Tetrapod Zoology

Oh, what the hell: given that we’ve already covered a new Wealden theropod, and have looked a bit at the palaeobiology of Majungasaurus within the week, I may as well resist my urge not to do more dinosaurs. In other words, I may as well cover Limusaurus as well, despite my previous protestations. It is, after all, a pretty incredible animal. Limusaurus is a small, long-legged dinosaur with short, gracile forelimbs, tiny hands, a slender neck and tail, a short, deep skull, and a slender lower jaw with a down-curved tip. It is toothless, and beak tissue is preserved around its jaw margins. This description makes it sound something like a sort of generalised small ornithischian (bar the toothlessness), but the incredible thing is that this is a ceratosaur, the first from the Jurassic of Asia (Xu et al. 2009) [the holotype is shown below. Scale bar = 50 mm. The coloured inset shows bone histology within the fibula: growth rings show that the specimen was about 5 years old at death. The yellow arrows point to a crocodyliform lying right next to the dinosaur!].

The big deal for me is that this dinosaur really is something radically new: all the ceratosaurs known previously are carnivores (or so it’s been assumed), typically with big heads, big teeth and all the other features you associate with predatory theropods. Yet again, the fossil record surprises us by showing that we can still discover entirely new, totally unexpected lineages.

I have to note to begin with that ‘ceratosaur’ is now being used in a more restrictive sense than the Gauthieresque version you might be familiar with: Ceratosauria does not include coelophysids or dilophosaurids in recent phylogenies, but is used only for the ceratosaurid + abelisauroid clade (or, more specifically, for all theropods closer to Ceratosaurus nasicornis than to birds).

One frivolous observation I have on Xu et al.’s paper is that the animal’s name – Limusaurus inextricabilis – is – in my totally irrelevant and entirely idiosyncratic personal opinion – inexcusably lame. Meaning something like ‘mire lizard, impossible to extricate’, it refers to the fact that the type specimen* seems to have died after getting trapped in mud. Oh, come on. A toothless, beaked, probably herbivorous, Asian ceratosaur with a fused sternal plate (!), surreal stumpy little hands, gastroliths, super-long feet… and they give it a name that tells us that ~~one~~ two individuals died after getting stuck in mud? Sigh.

* One of two specimens that are known, both are from the Oxfordian Shishugou Formation of the Junggar Basin, Xinjiang.

Its very long, slender hindlimbs indicate that it was cursorial. While long legs and cursorial abilities are not at all unusual for theropods, note that this is not necessarily the case for non-coelurosaurs. Indeed, ceratosaurs typically have proportionally short, stocky hindlimbs compared to coelurosaurs: look at Majungasaurus and the small abelisaur Masiakasaurus [shown here, from Carrano et al. (2002)], for example. While I’ve said that Limusaurus is ‘radically new’, you’ll note that this is only partly true, as one of the most interesting things about this animal is that, superficially, it’s very similar to certain Cretaceous coelurosaurs (notably ornithomimosaurs), and to the non-dinosaurian shuvosaurids of the Triassic. None of these groups are closely related, yet they converged on highly similar bauplans: shuvosaurids and Limusaurus are especially similar in having large mandibular fenestrae and abbreviated forelimbs (Xu et al. 2009).

All the fuss over those weird little hands

It’s the very weird little hands of Limusaurus [shown here] that are getting all the attention. It seems that four metacarpals were present: digit I (the thumb, or pollex) lacked phalanges (only a small metacarpal remained), digits II and III had large, robust metacarpals and three phalanges each, and digit IV was short, and perhaps with a tiny phalanx. While it’s generally been thought that non-avian theropods exhibit what’s been termed lateral digit reduction (LDR) – that is, they lost digits V and IV (and III in tyrannosauroids and a few others) – it’s pretty clear that Limusaurus exhibited bilateral digit reduction (BDR): that is, that it lost digits from both the lateral and medial sides of its hand.

As you’ll surely know, embryologists have often (though not always) argued that birds exhibit BDR, such that their tridactyl hands represent digits II, III and IV rather than the I, II and III thought universal among coelurosaurian theropods. Those who contend that birds cannot be theropods have latched on to this as an integral bit of their case: Alan Feduccia in particular has repeatedly said that bird hands and theropod hands are fundamentally different, and that this degree of difference bars theropods from avian ancestry (Burke & Feduccia 1997, Feduccia 1999, 2001, 2002, 2003, Feduccia & Nowicki 2002) [developing ostrich hands from Feduccia & Nowicki (2002) shown below]. Yeah, as if one feature – no matter how profound or major – can somehow outweigh tens of others: what excellent science. The hypothesis (note: hypothesis) that bird hands represent digits II-IV rests mostly on the fact that the primary axis of condensation (the first digit precursor to appear in the embryonic hand) corresponds to digit IV: because bird embryos grow two fingers medial to this axis, these two must be digits III and II (incidentally, this is contested by some embryologists and is not universally accepted. To keep things as simple as possible, we’ll ignore that for now).

Despite what Feduccia and his ‘birds are not dinosaurs’ colleagues state, the morphological evidence showing that birds really are theropod dinosaurs is overwhelmingly good, so if birds and other theropods really do have different digit patterns in the hand, something unusual must have occurred during evolution. One idea is that a frame shift occurred: that is, that the condensation axes that originally produced topographical digits II-IV became modified during later development, such that the digits that grew in these places came to resemble topographical digits I-III instead of II-IV (Wagner & Gauthier 1999). If the frame shift hypothesis is valid, then – somewhere in theropod evolution – the ‘true’ digit I was lost, and ‘true’ digit II became digit I. However, evidence from Hox genes indicates that the condensation axis for embryonic digit I receives a Hox signal normally associated with…. topographical digit I, thereby showing that the bird ‘thumb’ really IS the thumb (Vargas & Fallon 2005, Vargas et al. 2008).

Here’s where we come back to Limusaurus. Xu et al. (2009) contend that, having lost topographical digit I, this theropod was in the process of turning its topographical digit II into a developmental digit I. In other words, that its hand provides evidence for the frame shift hypothesis. Because Limusaurus is basal to Tetanurae (the theropod clade that includes birds and all of the more bird-like theropods), then the digits I-III we see in all tridactyl tetanurans are, after all, topographical digits II-IV, and the frame shift occurred well prior to the origin of birds. If true, this would provide a tidy explanation of the supposed discrepancy that exists between the embryological data and the inferences that palaeontologists have made from fossils. This is the main take-home message from Xu et al. (2009), and it’s the bit of the paper that everyone is talking about.

However…

By this way, this debate is pretty involved, so well done if you’ve followed it so far.

However… how sure are we that Limusaurus was really caught in the act of ‘frame shifting’? There’s no doubt that its digit I was absent, but was its topographical digit II really morphing into a ‘new thumb’? I’m not convinced. While metacarpal II in Limusaurus does possess a few subtle features normally seen on metacarpal I (such as a dorsolateral flange), we may just as well be seeing a very weird, reduced little hand where all the digits were becoming short and stumpy.

We already know that ceratosaurs did some very freaky things with their hands. One of the best known ceratosaurs, Carnotaurus, does not have long, allosaur-like clawed fingers as usually shown in artwork and movies: instead, it had short, apparently claw-less digits I-III, while digit IV was absent, with only a posteriorly projecting metacarpal remaining. In its close relative Aucasaurus, digit I was absent and only represented by a conical metacarpal, metacarpals II and III had just one or two phalanges each, and metacarpal IV was also conical and, apparently, devoid of phalanges [Aucasaurus forelimb shown here, from Coria et al. (2002)]. Because Carnotaurus and Aucasaurus are deeply nested within the ceratosaur clade Abelisauridae, it’s never been suggested that their bizarre, reduced little hands might be at all relevant to what happened in the avian hand. Why, then, is Limusaurus regarded as being so informative?

Part of the answer lies in the phylogenetic position recovered for this dinosaur by Xu et al. (2009): they state that it occupies ‘a very basal position within Ceratosauria’ (p. 941), and hence they imply that its hand anatomy might tell us something about the ancestral condition for tetanurans. However, one of the first things that struck me about Limusaurus is how gracile its metatarsus is. This is reminiscent of what’s seen in Elaphrosaurus (the ceratosaur regarded by Xu et al. (2009) as the closest relative of Limusaurus), but it’s also the condition present in noasaurid abelisauroids (like Noasaurus and Masiakasaurus). Andrea Cau reports at Theropoda that he finds Limusaurus to be a noasaurid, specifically one close to the much larger African taxon Deltadromeus (this would be amazing if true, as it raises the possibility that Deltadromeus was an edentulous herbivore/omnivore too – wow!). If Limusaurus is deeply nested within Ceratosauria, rather than down at its base, its peculiar hand morphology might – one could argue – be less significant in terms of big-picture implications. More work is needed to sort this out. Xu et al. (2009) analyse a lot of character data, and, while they do report finding Limusaurus to group with at least some noasaurids in at least some analyses (this is in the 101-page-long supplementary data, not in the published paper), they conclude that Limusaurus is close to Elaphrosaurus, and that both are outside of a clade that includes Ceratosaurus and abelisauroids (noasaurids + abelisaurids). This position is only very weakly supported (it hangs on one character!) and, as noted above, might be wrong.

Don’t get me wrong: I think it’s certainly conceivable that Limusaurus says what the authors think it might… that a frame shift occurred pretty early in theropods, and that the topographical second digit came to function as a homologue of the first digit. However, the hand of Limusaurus is so weird, and the phylogenetic position of this theropod within Ceratosauria is so contestable, that I think this is open to question. And, as expressed here – I hope – I really think that the more interesting details about this animal are being mostly overlooked. A toothless, beaked ceratosaur, convegent on ornithomimosaurs and shuvosaurids, from the Jurassic of Asia… wow. Just, wow…

That really will be it on dinosaurs for a while now, I promise. Limusaurus has also been covered by Dave Hone (I should hope so, he’s on the authorship), Pharyngula, at Panda’s Thumb, by Carl Zimmer, and by a million others I’m sure. This is why I don’t like blogging about new discoveries. Anyway, for previous articles on Mesozoic theropods see…

Refs – -

Burke, A. C. & Feduccia, A. 1997. Development patterns and the identification of homologies in the avian hand. Science 278, 666-668.

Carrano, M. T., Sampson, S. D. & Forster, C. A. 2002. The osteology of Masiakasaurus knopfleri, a small abelisauroid (Dinosauria: Theropoda) from the Late Cretaceous of Madagascar. Journal of Vertebrate Paleontology 22, 510-534.

Coria, R. A., Chiappe, L. M. & Dingus, L. 2002. A new close relative of Carnotaurus sastrei Bonaparte 1985 (Theropoda: Abelisauridae) from the Late Cretaceous of Patagonia. Journal of Vertebrate Paleontology 22, 460-465.

Feduccia, A. 1999. 1,2,3 = 2,3,4: accomodating the cladogram. Proceedings of the National Academy of Sciences 96, 4740-4742.

- . 2001. Digit homology of birds and dinosaurs: accomodating the cladogram. Trends in Ecology & Evolution 16, 285-286.

- . 2002. Birds are dinosaurs: simple answer to a complex problem. The Auk 119, 1187-1201.

- . 2003. Bird origins: problem solved, but the debate continues… Trends in Ecology and Evolution 18, 9-10.

- . & Nowicki, J. 2002. The hand of birds revealed by early ostrich embryos. Naturwissenschaften 89, 391-393.

Vargas, A. O. & Fallon, J. F. 2005. Birds have dinosaur wings: the molecular evidence. Journal of Experimental Zoology (Mol Dev Evol) 304B, 86-90.

- ., Kohlsdorf, T., Fallon, J. F., VandenBrooks, J. & Wagner, G. P. 2008. The evolution of HoxD-11 expression in the bird wing: insights from Alligator mississippiensis. PLoS ONE 3(10): e3325 doi:10.1371/journal.pone.0003325

Wagner, G. P. & Gauthier, J. A. 1999. 1,2,3 = 2,3,4: a solution to the problem of the homology of the digits in the avian hand. Proceedings of the National Academy of Sciences 96, 5111-5116.

Xu X, Clark JM, Mo J, Choiniere J, Forster CA, Erickson GM, Hone DW, Sullivan C, Eberth DA, Nesbitt S, Zhao Q, Hernandez R, Jia CK, Han FL, & Guo Y (2009). A Jurassic ceratosaur from China helps clarify avian digital homologies. Nature, 459 (7249), 940-4 PMID: 19536256

Comments

#1 Tim Morris
June 19, 2009

my only major beef with this critter’s media release is that they’ve illustrated it with feathers, when it’s a *ceratosaur* of all things. I know anything goes now, in the age of Tiyanulong, but seriously, I miss scaly theropods. Ceratosaurs and coelophysoids have always been my favorite because they’re awesome, scaly brutes, that illutstration that comes with it reminds me of Avimimus more than a ceratosaur.
#2 Andrea Cau
June 19, 2009

Hi, Darren!
Great post: I agree with all you wrote!
See my second post about Limusaurus’s hand, citing some basal tetanurans challenging part of the scenario depicted by Xu et al. (2009):
http://theropoda.blogspot.com/2009/06/limusaurus-inextricabilis-xu-et-al-2009_19.html
#3 Adam
June 19, 2009

I had the same thoughts about the name. On the drive home from work I found myself thinking of other potential names that were missed out on, Saurimitator was my fave (after Struthiomimimimus). All in all a really cool dinosaur and easily the most important new species for a long long time.
#4 Michael P. Taylor
June 19, 2009

Adam,

The name Struthiomimimimus would have been pretty cool; but don’t forget that this thing is morphologically convergent on the crurotarsan Effigia, which is itself an ornithomimosaur mimic. So a more appropriate name would be Ornithomimomimomimus.

I wonder if they considered it?
#5 Andrea Cau
June 19, 2009

Topographical digit II of Limusaurus possesses three phalanges, not two.
#6 Darren Naish
June 19, 2009

Topographical digit II of Limusaurus possesses three phalanges, not two.

Oops. I got this right early on in the text, just not on the second occasion. I’ll go back and correct it, thanks for noticing.
#7 David Marjanović
June 19, 2009

I can’t comment on Andrea’s blog (maybe it’s just Safari, but there’s nothing clickable anywhere close to “posta un commento”), so:

B1: L’ipotesi embriologica sulla mano aviaria è errata. Probabilmente, non è sempre vero che l’analisi embriologica dimostri l’omologia nelle dita della mano. In base a questa versione, la mano degli uccelli moderni, pur sembrando derivare dalle dita II-III-IV, sarebbe in realtà composta da I-II-III come nei theropodi.

That’s what I think.* In his latest paper, Kundrát found six things in the developing ostrich wing and mentioned two possible interpretations: fingers I through V and the pisiform, or the prepollex and fingers I through V. He immediately went on to dismiss the latter because a prepollex has never been found in Alligator. But what if the prepollex has returned as a byproduct of the fact that birds (and other coelurosaurs) generally emphasize the cranial margin of the forelimb? The prepollex is well known in many adult lissamphibians and in the ontogeny of the mouse lemur Microcebus; and no pisiform has ever been found in a non-neornithean dinosaur.

(Based on Tulerpeton, I personally wonder if the pisiform is the near-mythical postminimus. But I digress.)

Besides, even under the frameshift hypothesis, Mononykus has lost fingers III and IV (as a comparison to Shuvuuia easily shows) and thus falsifies the strict interpretation of the pyramid reduction hypothesis, unless yet another frameshift or suchlike is postulated out of nowhere.

* translate.google.com being what it is, I tried to read the original. Takes some time, but works pretty well with French, Latin, and elementary Spanish under my belt. So here’s my translation: “[Possibility] B1: The embryological hypothesis about the avian hand is erroneous. Probably it is not always true that embryological analysis demonstrates homology between fingers. Based on this version, the hand of the modern birds, although seeming to derive from fingers II-III-IV, is actually composed of I-II-III as in the theropods.” Any mistakes?
#8 Scott Hartman
June 19, 2009

>>>my only major beef with this critter’s media release is that they’ve illustrated it with feathers, when it’s a *ceratosaur* of all things.<<<

I admit I would have gone a different direction,but with dino-fuzzish structures plausibly argued as being basal to dinosaurs it’s a perfectly reasonable interpretation. I’m much more concerned about the bizzarely abbreviated tail they illustrated it with (not to mention the fact that the sacrum must be broken for the tail to exit the pelvis at that angle! Ouch!!!).

Granted the tail of the type is incomplete, but ceratosaurs generally have long, generous tail proportions, and the preserved tail in the fossil shows no signs of tapering off that quickly.
#9 Edgar
June 19, 2009

Agreed with first comment, any abelisaur appeared to be feathered…
#10 David Marjanović
June 19, 2009

not to mention the fact that the sacrum must be broken for the tail to exit the pelvis at that angle! Ouch!!!

Yeah. Obviously the artist is only familiar with mammalian hindquarters. Just try to imagine the shape of the ilium in that thing, based on the shape of the thigh… looks outright human.
#11 Darren Naish
June 19, 2009

I chose not to say nasty things about the artwork; I like its muppetness.

As for furry integuments on non-coelurosaurian theropods, serious question: given what we now know about the integument in basal ornithischians (well, one basal ornithischian) and pterosaurs, should a fuzzy covering be the default integument for small dinosaurs?
#12 Brett Booth
June 19, 2009

The artist simply ran out of room. That’s why the tails are short. I think the straight ‘raptor’ tail idea prevented them from curving it.
#13 Andrea Cau
June 19, 2009

@David, your translation is perfect!
Would you like to work for me? The google.translator is often terribly wrong… very frustrating!

@Darren, this is my opinion about ornithodiran integument.
#14 Zach Miller
June 19, 2009

Darren, I do think that protofeathers should be the default for small dinosaurs (and pterosaurs). Great article–I’ll jump in here and say that the BAND perspective will be posted at my blog before the end of the day.

And shuvosaurs aren’t ornithomimosaur-mimics, it’s the other way around (since shuvosaurs came first). You might say that ostrich dinosaurs are limusaur mimics, and limusaurs are shuvosaur mimics.

I hate the name, too.
#15 Michael Erickson
June 19, 2009

WHY DO ALL THESE AWESOME NEW DINOSAURS KEEP GETTIN’ SUCH LAME, CRAPPY NAMES????!!! CRAPPY CRAPPY CRAPPY!!!!!!! Phew. I’m under control now. Anywho, an amazing, awesome discovery, by any name. About the feathers, I think it’s going a wee bit too far to start putting fuzzy junk on EVERYTHING just because pterosaurs and a basal ornithischian have it. Besides, is there really any proof that ptero-fuzz has anything to do with dino-fuzz? Really, I’m innocently curious. Also, I’m not quite sure that Tianyulong does much for the “all ornithodirans were fuzzy” thing. I mean, those structures on its tail look more like the quills of psitticosaurs (which I personally don’t think have much to do with feathers at all) than the protofeathers of Sinosauropteryx.
#16 Michael Erickson
June 19, 2009

That painting, by the way, looks a freakin’ muppet. I… LOVE IT! Accurate or not, I think it’s just adorable!
#17 Michael Erickson
June 19, 2009

About comment 15: Feel free to try and convince me otherwise about feathers and fuzz.
#18 Bob Michaels
June 19, 2009

I am more perplexed about this conundrum. What came first the Dinosaur or the egg? Can anyone solve this or offer a rational hypothesis?

thank you
#19 I. M. Anonymous
June 19, 2009

Bob, if you’re serious: animals had been producing eggs for tens of millions of years before dinosaurs came along.

If you’re not being serious: not funny.
#20 Michael Erickson
June 19, 2009

Bob Michaels: What the…? Seriously, dude, you need to get a life. You must have WAY to much time on your hands if you can watse it writing that nonsense on a SCIENCE BLOG.
#21 Michael Erickson
June 19, 2009

Zayiflama: What is wrong with you? Why do you keep taking quotes from other peoples’ comments (which taken out of context often make no sense) and post them yourself? You’ve done this to me and to Scott Hartman, and frankly I’m sick of it. Either post your own comments, or get lost. Thank you.
#22 Bob Michaels
June 19, 2009

I am very serious, it`s an important part of unanswered evolutiuonary theory and has much too long gone unanswered.i am in the process of delving into this phenomenon
#23 Michael Erickson
June 19, 2009

Bob Michaels: Animals were laying eggs millions upon millions of years before dinosaurs appeared. Therefore, the egg came first. There. You have your answer, idiot. Now leave us alone.
#24 Owlmirror
June 19, 2009

@#22: Zayiflama is a Turkish comment spammer. That’s why.

A Turkish-to-English dictionary says that “zayıflama” means “reducing, slimming” (and “bilgileri” means “knowledge, learning, cognizance, information (etc)”)

I would infer that the link is for some sort of weight loss/diet pill site. I am not going to follow the link, though, since there may well be unpleasant browser hijack scripts on the other end.
#25 Owlmirror
June 19, 2009

Ah, I see that the spam comment was deleted already, changing the comment numbering. D’oh.

My #24 should refer to @#21, now. Sorry.
#26 Michael Erickson
June 19, 2009

Ok, Owlmirror, I get it now. I thought that Zayiflama was just an idiotic individual with way too much time on their hands.
#27 Bob Michaels
June 19, 2009

Mr Erickson I believe, It`s obvious the Dinosaur came first and then the Egg, where is your logic me boy?
#28 Michael Erickson
June 19, 2009

Bob Michaels, you’re REALLY getting on my nerves. This is a SCIENCE BLOG. These are supposed to be SERIOUS comments. Either you’re mentally retarded, or you’re just trying to bother people, at which, I am sorry to say, you have already succeded at. Again, this is SCIENCE BLOG. Our comments should protain to SCIENCE. I’ve had enough of your nonsense. Enough is enough.
#29 Michael Erickson
June 19, 2009

You, Bob Michaels, are doing nothing but wasting space. Get lost, turkey. And I AM serious.
#30 jck
June 19, 2009

Outside of wings and therizinosaur claws there seems to be relatively little discussion of theropod forelimbs. Given the variety of forms they take, I would think that they had to serve purposes other than flapping or digging. There seem to be a lot of species with tiny forelimbs but they all seem to be tiny in different ways. Would that mean they all became vestigial in different ways or is something else going on?
#31 Michael Erickson
June 19, 2009

Bob Michaels, I just want to say that if I were you, I wouldn’t say another word on this thread. The next comment of yours that relates to your “question” very well may be responded to with a comment so hate-filled, rotten, and unpleasent that I wouldn’t be surprised if Darren deleted it. Be wise. LEAVE MY PRESENCE, AND LEAVE THE PRESENCE OF ALL THE OTHER INNOCENT TET ZOOERS THAT ARE BEING SUBJECTED TO YOUR IDIOCY.
#32 Michael Erickson
June 19, 2009

Andrea Cau: I LOVE LOVE LOVE your blog. There’s just one little problem: I can’t read it. Google translator is so crappy that I often don’t even know what the post I’m reading is supposed to be about. If only there was some way I could read it, I’d be a happy theropod-lover. Happy indeed.
#33 Michael Erickson
June 19, 2009

I seem to be the only one commenting – what’s with the dark silence that has decended over this article? Anywho, I’ve got a very revelant question – Where can I find the PDF for this sucker? Darren said that one exsisted, but I haven’t been able to locate it. Help! Please! I’m sinking in the mud*!

*Pun on name of new dinosaur
#34 Rhys D.
June 19, 2009

Hi, first time posting here. I’ve got to say, little Limusaurus (I kinda think the name’s cute) is a really impressive animal. I mean, damn, it’s so distinct, so unique, and surprisingly important, and in such an unassuming looking animal. Screw Darwinius, Limusaurus is WAY more impressive.
#35 Michael Erickson
June 19, 2009

Rhys D: Welcome to Tetrapod Zoology! Yes, SCREW DARWINIUS! There’s no way some stinkin’ little mammal can beat such an awesome, important dinosaur! Long live Limusaurus!
#36 Michael Erickson
June 19, 2009

I have a soft spot for animals, and I think that a living Limusaurus would be simply precious. I mean, look at that skull. It’s face must have been so cute!
#37 Michael Erickson
June 19, 2009

And its tiny little hands. Awww! Adorable.
#38 Rhys D.
June 19, 2009

@Michael Erickson: Thanks! I know right? Sure, Darwinius is a beautifully preserved fossil, but it hardly has ANY relevancy to human evolution.

And dino-fuzz or no dino-fuzz, Limusaurus is a cute little animal. I want one for a pet!
#39 Michael Erickson
June 19, 2009

You’re quite welcome. Yes, I want (no, need) one for a pet as well. It’s just too adorable.
#40 Andrea Cau
June 20, 2009

@Michael Erickson:
Thank you for loving my blog!
Unfortunately, I’m an Italian mother-language, and my English is not so good for being the language of my posts (I like using rethoric, play of words and so on, while when I write in English I’m too linear and stereotyped…): in fact, it’s (almost) good for my (modest) scientific productions, but not for writing a blog.
It’s a good limitation, given that there’s a growing number of non-Italian readers of my blog: I’ll find a solution, but I don’t know if I’ll ever write entirely in English…
#41 Jura
June 20, 2009

Darren wrote:

As for furry integuments on non-coelurosaurian theropods, serious question: given what we now know about the integument in basal ornithischians (well, one basal ornithischian) and pterosaurs, should a fuzzy covering be the default integument for small dinosaurs?

I get that putting feathers on bloody everything, is now in vogue, but seriously guys, lets pull it back some.

As scientists, we are supposed to take a parsimonious approach to data interpretation. I get that a lot of dinosaur paleontologists have a thing for feathers, but that’s no excuse to ignore Occam’s Razor.

Throw Tianyulong, Sinosauropteryx, Psittaccsaurus and Sordes on a cladogram with representatives from the other major branches of Archosauria, and it becomes pretty apparent that fuzzy integument (if indeed, what we see on some of these ornithischians, is really integument), is most likely not related to any of these groups.

Remember, we have skin impressions for the majority of dinosaur groups now. Almost all of them show the presence of scales. Since scales do not equal naked skin, this means that if “fuzz” was the default trait for dinosaurs, or ornithodirans, then it had to have been lost at least 7 different times. Furthermore, scales would have to have re-evolved another 7 times. That’s a whole lot of steps required to make all dinosaurs fuzzy (even if we assume simultaneous loss and re-evolution, that’s still at least 7 steps). Especially when “fuzz” convergence need only happen 4 times.

As for those who will inevitably push the “we have scales on body section X, that doesn’t mean feathers couldn’t have been everywhere else” angle, I would like to point out that there have been a number of evo/devo studies which show that, while scales and feathers are intertwined developmentally, their relationship is an antagonistic one (e.g. Gregg et al 1984, or Sawyer & Knapp 2003). Feathers suppress scale development, and scales (when re-evolved in birds) suppress feather development. So, yeah, scales on any part of the body (save the tibial-tarsal, and possibly head regions. And that’s just because they are part of a different integumental cascade) are a pretty likely indicator of scales all over the body.

So, in regards to Tim Morris’s comment; yeah making Limusaurus fuzzy is just as scientifically inaccurate as making Velociraptor scaly.

Quick refs:

Gregg, K., Wilton, S.D., Parry, D.A., and Rogers, G.E. 1984. A Comparison of Genomic Coding Sequences for Feather and Scale Keratins: Structural and Evolutionary Implications. Embo J. Vol.3(1): 175-178.

Sawyer, R.H. and Knapp, L.W. 2003. Avian skin Development and the Evolutionary Origins of Feathers. J. Exp. Zool. (Mol Dev Evol). Vol.298B:57-72.
#42 Nathan Myers
June 20, 2009

I wish to go on record here admitting that my example, in a previous thread suggesting to David M. that some phylogenetically relevant facts would be hard to code in an input matrix, was, to the best of my knowledge, completely fictitious. That it involved uncertainty about digit numbering almost identical to that presented above was — and I mean this entirely, literally, and seriously — completely coincidental. I was not being disingenuous, I really am, as I said, pig-ignorant. I do wonder what the timely coincidence says about the customary insistence on parsimony.

On a completely different note, I wonder if people posting here would find L. so muppetifically cute if it had been reconstructed more like a Skeksis.

Finally, Michael, sometimes it’s better to leave a comment in the edit window for an hour or so before hitting “Post”, in case you have further, or second, or (better) third thoughts, rather than posting and re-posting ad infinitum. (I.e., if you would like us to take the time to think through your remarks, won’t you please do so yourself?) Also, direct commands to other correspondents, no matter how annoying they may be, seldom lead to a desirable result. This is particularly the case with trolls, for whom exhaustive experience demonstrates the only useful response is to ignore them.
#43 Andreas Johansson
June 20, 2009

In addition to be dull, Limusaurus is also crappy Latin – the stem isn’t “limu-” but “limo-”.

Maybe David and I should set up a consulting bureau helping authors to get their classical languages right when coining scientific names?
#44 Andrea Cau
June 20, 2009

Jura,
I think we have to follow Hutchinson & Allen (2009)’s message: the “scaly-feather (or scaly-fuzz)” may be a false dicothomy. Birds are feathered and scaly at the same time, in different body regions. Microraptor was more feathered than modern birds. Psittacosaurus was less fuzzy than Tianyulong. Euoplocephalus was more scaly than Psittacosaurus. It’s a continuum of fuz-scales body covering distribution. Given that dermal scales, bony scales and fuzz/feathers preservational conditions are different, I think we have not to read the fossil record literally. I remember that not all the Archaeopteryx specimens shows feathers: were they scaly? The ventral surface of the Scansoriopteryx’s tail shows tubercolate scales: was it entirely scaly? Idem, Juravenator. Scipionyx preserves the the intestine, but no fuzz or scales: was is naked? (In my opinion, all the answers are: “No”).

Hutchinson J.R. & Allen V., 2009 – The evolutionary continuum of limb function from early theropods to birds. Naturwissenschaften. DOI 10.1007/s00114-008-0488-3.
#45 zayıflama
June 20, 2009

I get that putting feathers on bloody everything, is now in vogue, but seriously guys, lets pull it back some.
#46 Andrea Cau
June 20, 2009

In the post, Darren cited my hypothesis that Limusaurus would be close to Deltadromeus. I’ve re-run my data matrix, after the inclusion of new characters present in the supplementary data of Xu et al. (2009). Now, Limusaurus results a basal ceratosaur, siste-group of Elaphrosaurus.

In my opinion, this result is not a stronger support to the notion that manual I reduction is a synapomorphy of Averostra: other (more derived) ceratosaurs (Ceratosaurus, Aucasaurus) and the basal tetanurans bearing four metacarpals (Xuanhanosaurus, Megaraptor) show a more robust Mc I, often bearing articulated phalanges. So, it’s more parsimonious to consider the condition in Limusaurus as an autapomorphy.
#47 Steve P
June 20, 2009

If secondary loss of feathers always resulted in naked skin, I’d be inclined, as other posters have stated, to be cautious of depicting Limusaurus and any other groups not shown to have definitely had feathers, as having been feathered.

However, if secondary loss of feathers does not necessitate naked skin but could allow reversion back to scales, I’d be inclined to agree with the existence of a feathered basal dinosaur. I wonder how (or indeed if) this could be tested? The comment above (44 by Andrea) sums up a lot of what I would’ve said well – I like the point he makes regarding the possible false dichotomy between scaled or not scaled, nowhere in between – my chickens still have scaly feet (though their faces are not scaly where feathers are absent…).

Large mammals obviously wind up with naked (albeit thick) skin when they lose their fur. I would think that no known post-Mesozoic birds attained large enough sizes to warrant loss of feathers, though I did just read (admittedly on Wikipedia) that the feathers of Gastornis (which I dearly wish was still Diatryma… sigh) are unknown – is there any possibility that these birds were secondarily featherless? I know moas definitely had feathers (as they were used ceremonially by the Maoris), though don’t know about Aepyornis either. Just throwing it out there…
#48 Andrea Cau
June 20, 2009

The fact that large-sized (tropical) mammals lose their fur does not mean that large dinosaurs followed the same trend.

Stupid suggestion: in large mammals, the loss of fur is related to the surface/volume ratio and the dissipation of heat. A large dinosaur, with a long tail and/or long neck, and (?) air sacs, maybe should not lose the fuzz-feathers to maintain an efficient temperature control.
#49 David Marjanović
June 20, 2009

David, your translation is perfect! Would you like to work for me?

Gladly. Just give me a few extra hours per day.

Where can I find the PDF for this sucker?

By begging someone who has it.

Or by FedExing about forty pounds of Sterling silver to Macmillan Inc., the corporation that publishes Nature. As Austin Powers said: “Capitalism! Yyyyyyyeeeeeah.”

Remember, we have skin impressions for the majority of dinosaur groups now. Almost all of them show the presence of scales. Since scales do not equal naked skin, this means that if “fuzz” was the default trait for dinosaurs, or ornithodirans, then it had to have been lost at least 7 different times. Furthermore, scales would have to have re-evolved another 7 times. That’s a whole lot of steps required to make all dinosaurs fuzzy (even if we assume simultaneous loss and re-evolution, that’s still at least 7 steps). Especially when “fuzz” convergence need only happen 4 times.

What if there was a switch between scales and feathers, and what if selection for each orientation of the switch was size-related?

Maybe David and I should set up a consulting bureau helping authors to get their classical languages right when coining scientific names?

If Nick Pharris joins. I don’t know Greek.

I remember that not all the Archaeopteryx specimens shows feathers: were they scaly?

No, they drifted around rotting for too long, so the skin isn’t preserved at all.

Scipionyx is a different case: its internal organs rotted so fast that they caused calcium phosphate and the like to precipitate, while the skin lasted longer and is gone entirely.

A large dinosaur, with a long tail and/or long neck, and (?) air sacs, maybe should not lose the fuzz-feathers to maintain an efficient temperature control.

We do have completely scaly titanosaur hatchlings from Argentina…

==================

Darren, the spambot is back (currently comment 45). Ask PZ how to ban it.
#50 Andrea Cau
June 20, 2009

@49:”No, they drifted around rotting for too long, so the skin isn’t preserved at all.”

Yes, exactly what I meant: different taphonomic conditions among specimens of the same species produce different preservations. So, we would avoid to read “literally” the distribution of integument among fossils. It has to be interpreted in phylogenetic-ecologic-climatic context.

“We do have completely scaly titanosaur hatchlings from Argentina…”
They are probably lithostrotians: a derived lineage of heavy armored neosauropods. In my scaly-fuzzy gradient model shown in Comment N°13, they’re placed at the scaly top of the continuum.
#51 Michael Erickson
June 20, 2009

Nathan Myers: What makes you think that I don’t think through my remarks? And yes, It probably isn’t best for me to go beserk on annoying correspondents. I just wish we could stay serious here. It makes me upset when trolls like Bob Michaels waste space and our time with garbage like “What came first the Dinosaur or the egg”. This isn’t a joke/riddle/nonsense blog, it’s a science blog, and I just wish we could all do our part to keep it that way. But I understand that some people are just fools who don’t plan on doing this, and I’ll keep it under control next time. My comments did scare him off, though.
#52 Nathan Myers
June 20, 2009

Michael E.: Hank the Cowdog succeeds in scaring off the postman every time… Postings at (e.g.) 1:38, 1:41, 1:47 suggest haste. We all would much rather feel like “Oh, good, a Michael E. posting!” than “Oh, no, not another Michael E. posting.”

David M.: “…completely scaly titanosaur hatchlings” seems to me to cinch the question. I guess I’m speculating that hatchlings ought to tell us more about the basal condition.
#53 Michael Erickson
June 20, 2009

Okie Dokie, Nathan. I understand. Oh, and I’ve got a very good, well thought-out comment coming right now.
#54 Michael Erickson
June 20, 2009

I agree with Jura 100% on this dino-fuzz thing.

Reasons that we have gone WAY WAY WAY too far with fuzz:

Reason 1) We have skin impressions from nearly every major dinosaur clade there is. What do these impressions show? SCALES, SCALES, SCALES, AND MORE SCALES. In nearly every case, skin impressions reveal dinosaurs to have been scaly. Scaly hides are known to have been present in:

Ceratopsians

Stegosaurs

Ankylosaurs

Hadrosaurs

Sauropods (including embryos)

Most Theropods (including ceratosaurs, allosaurs, and tyrannosaurs)

Dinosaurs were VERY, VERY scaly. (Proto)feathers are the EXEPTION. They are not the rule.

Reason 2) The often-used counter-argument to Reason 1) is that (proto)feathers could have been lost as animals grew larger, or perhaps (proto)feathers were an ontogenetic affair – with fuzzy babies growing bald as they hit adulthood. But there’s a flaw in this counter-argument: Scales, you see, are NOT the same as naked skin. Scales, just like feathers, are a type of integument. They lie on top of the epidermis. Which brings us to…

Reason 3) It has also often been said (even on here) that since birds have both scales and feathers, both types of integument could have been present on dinosaurs as well. But this argument is also flawed, as it generalizes the relationship between scales and feathers. Scales in birds do NOT occur because of an absence of feathers. In reality, they occur from active surpression of feather formation. Look at a plucked chicken, and you will notice a very distinct lack of scales on the whole of the body, minus the feet. Then there are ostriches, which are special in having lost a good deal of their integument. Take a good look at the featherless legs and neck of an ostrich. There are no scales to be seen. The only scales on the body occur on the tarsometatarsal portion of the bird. There is actually a very sharp demarcation where this occurs, something that agrees well with Alibardi & Thompson’s (2001) studies that show how integument formation occurs in diapsids.

Reason 4) Feather B-Keratin proteins are probably homologous with the scale B-Keratin proteins. However, they are also smaller than scale proteins. This, and the contents of Reason 3), when taken together, strongly suggests that the relationship between scales and feathers is an antagonistic one. One that determines integument placement based off of where one protein ends, and another begins. To put it another way, it’s time to stop putting feathery mohawks on scaly dinosaurs. It’s just way too unlikely. The ontogenetic argument is even less likely, because it requires that dinosaurs lost one type of integument as babies, revealing a naked skin, then grew a completely different type when they reached adulthood. This would make dinosaurs unique AMONG ALL VERTEBRATES in doing this. We need to quit with the fuzzy T. rex and hadrosaur hatchlings.

Reason 5) This one’s gonna stir up trouble, although it shouldn’t. It’s the plain truth, and you can love it or lump it. Here we go…
Compsognathus. Here we have an animal well within the known protofeather brondries, closely related to Sinosauropteryx, that is known to be scaly. Yes, scaly. In Peyer’s recent (2004) redescription of the French Compsognathus specimen, Peyer identifies on the tail “13 patches of uniformly sized, bumpy structures… resembling the turbercles forming the integument of Juravenator in their shape, arrangment, and relative size”, which are present up until the very last preserved caudal vertebra on the specimen. Reasons 3) and 4) show why it’s very unlikely that Compsognathus would have had scales on the tail and feathers everywhere else. Besides, Sinosauropteryx has a decidedly fluffy tail. So, as I said, here we have an animal, well within the known phylogenetic boundries of protofeathers, that was scaly. This should help to show very well why we have gone WAY too far with our distribution of fuzz and fluff. And as a side note, depictions of Compsognathus with fuzz, a la Sinosauropteryx, should stop immediately. Those depictions are probably wrong.
#55 Michael Erickson
June 20, 2009

I’m so sorry for posting my comment twice. I have no clue how it happened.
#56 Michael Erickson
June 20, 2009

Now I get it. The first occurence of my comment shouldn’t be there; I clicked “Post” when I meant to click “Preview”. It’s the second comment of mine that’s meant to be read, not the first. Again, I’m sorry.
#57 Spudley7
June 20, 2009

Michael, Tetrapod Zoology has become the ‘Michael Erickson show’ recently. Please, dude, tone it down a bit. Your enthusiasm and passion are great, but we don’t need ten or more of your thoughts for every single post. Don’t take this as an attack – more as a bit of friendly advice.
#58 Michael Erickson
June 20, 2009

Sure, I’ll tone it down a bit. But if you’re referring to my most recent (and longest) comment being shown twice, it was a MISTAKE. An ACCIDENT. But aside from that, I’m not sure what I’m supposed to do if I have a lot to say. Just not say it? It is America, after all. But I suppose I still could combine several small comments into one big comment. Would that help?
#59 Dr. Nick
June 20, 2009

Maybe David and I should set up a consulting bureau helping authors to get their classical languages right when coining scientific names?

If Nick Pharris joins. I don’t know Greek.

Thanks, David!

I’m no expert, really, but I’m game!
#60 Andreas Johansson
June 20, 2009

@Michael: If you regularly have this much to say, you might want to consider starting your own blog. There can, after all, never be too many biology blogs on the ‘Net.
#61 Michael Erickson
June 20, 2009

That’s a good idea, Andreas. I just might do that. Thanks!
#62 David Marjanović
June 20, 2009

But I suppose I still could combine several small comments into one big comment. Would that help?

Yes, as would a blog of your own.

I have to read Peyer (2004) again. Something is fishy here.
#63 Michael Erickson
June 20, 2009

Yes, a blog of my own would be nice. But is the world ready for it? That’s the question.
#64 Michael Erickson
June 20, 2009

I’m sorry, I know that I’ve been posting way too much. But this is urgent. Zach Miller over at When Pigs Fly returns is saying that Limusaurus is a bird, and that it proves that birds are not dinosaurs. What the…? I desperately need help here. What in Heaven’s name going on with this?
#65 Hai~Ren
June 20, 2009

Michael Erickson: Zach’s just being sarcastic and imagining how a BANDit might try to get Limusaurus to fit the BANDit framework.
#66 Michael Erickson
June 20, 2009

Okay, I get it now. That’s halarious! Thank you!
#67 AnJaCo
June 20, 2009

David Marjanović:
It seems that Limosaurus may be preoccupied, a Google book search yields the following:
one
two
three
These old refs seem to discuss Limosaurus in the context of stratigraphy rather than taxonomy, so specifically what this critter was is not clear. To me anyways. Perhaps you can penetrate the language of the last one, it seems to be in German. Sauropterygian of some sort perhaps?
Given the paucity of recent search results I would guess that Limosaurus has been sunk into synonymy by now, somewhere…
#68 DDeden
June 20, 2009

Maybe emusaurus rather than limusaurus?

I think this theropod was derived from an omnivorous fly-gliding archosaur that became isolated on a small volcanic island rich in short plants and poor in animal prey, when sea levels dropped it migrated back to the continent. Might the feet have had some webbing? Could it have fed on shallow benthic seafood also (noting the gastroliths, for grinding and ballast, as in penguins and crocs)? Could the fused sternal plate parallel the early turtle fused plastron for ballast and/or armor (males pecking at each other’s colorful chests?)? Were its legs particularly densely boned (for wading in deepish lagoon water on mud) or lightly boned for endurance running?
http://scienceblogs.com/pharyngula/2008/11/odontochelys_a_transitional_tu.php
#69 Michael Erickson
June 21, 2009

Since this is an article is on theropods, I’d rather ask my question here than on one of the next articles Darren posts. Does anyone know if a good skeletal recontruction of Troodon formosus exists? I’ve looked everywhere and can’t seem to find one. If anybody can help me I’d greatly appreciate it. (And please don’t get mad at me for posting another comment; If I casn’t ask my question here, where can I ask it? Even if I have posted a lot of comments lately, I still should be able to ask a serious scientific question on a science blog without being attacked.)
#70 Zach Miller
June 21, 2009

Jaime Headden’s gotta have done Troodon. Check out the DinoForum and troll around looking for Qilong’s posts. That’s Jaime, he’s kind of a god when it comes to skeletals.

And yeah, Mike, that Limusaurus article is a parody of BAND. If I convinced just ONE PERSON…I’ve totally done my job. Now BAND itself will hijack my post, claim that Limusaurus is a ratite, and we will LAUGH AND LAUGH AND LAUGH.

I’m surprised the flying pig in the background didn’t clue you in.
#71 Michael Eickson
June 21, 2009

Hey Zach, thanks for the heads-up on the Troodonskeletal. I saw the flying pig in the background of the drawing, but I thought it was just there because the name of the blog is When Pigs Fly Returns, not because the article was a joke! I really thought you had totally lost your mind and turned BAND on us! What a stupid bag ‘o nuts I am…
#72 Michael Erickson
June 21, 2009

Wait a second, Zach… I don’t have access to DinoForum! Any more bright Troodon ideas?
#73 Michael Erickson
June 21, 2009

Oh, never mind Zach. Now I see that registration is free. I really am a stupid bag ‘o nuts!
#74 Eric
June 21, 2009

>>>Reason 1) We have skin impressions from nearly every major dinosaur clade there is. What do these impressions show? SCALES, SCALES, SCALES, AND MORE SCALES. In nearly every case, skin impressions reveal dinosaurs to have been scaly. Scaly hides are known to have been present in:

Ceratopsians”

I’m pretty sure that their is a well preserved triceratops with what appear to be bristles in amongst the skin.

Plus, I seem to recall that the many examples of scaly skin found amongst the dinosaurs you mentioned, are from areas of the body that are not really part of the main hide(with hadrosaurs and sauropods the exception). Indeed I find it odd that theriznosaurs are depicted as fuzzy, even large ones. Of course this stems from the fact that bei piosaurus has been found with fuzz. But dilong has been found with fuzz, so why don’t we extend this to tyrannosaurs? Gigantoraptor has also been illustrated with fuzz, presumably because of finds of a related oviraptor in Liaoning and finds like “Big Mama” having their arms in a position over their eggs which imply that they were feathery in some way. And since oviraptor appeared to have feathers and yet some species were man sized or bigger, why can we not extend this to other theropods of similar size. Maybe the ceratosaur skin was found directly on the hide but I am not so certain that it is. So in absence of this knowledge it seems that the fossilized skin doesn’t congregate in areas that might hold feathers.

The scales on compsognathus strike me as odd. After all theropods were pneumatic so they could be much cooler compared to animals without air sacs in their vertebrae. And wasn’t the presence of scales brought up by Von Huene and later struck down by Osborn? Anyway compsognathus seem much smaller than beipiaosaurus, which has been perserved with fuzz indicating that relatively large dinosaurs would have retained their plumage. Maybe this is one of the things we will never know.

Personally though, I find the image to be look more like the artist was painting an ornithominoid then a ceratosaur. Althrough it is still a nice piece of art.
#75 Darren Naish
June 21, 2009

AnJaCo (comment 67) notes that Limosaurus seems to be preoccupied, as a few sources refer to a Limosaurus gaillardoti. These are definitely references to the nothosauroid Simosaurus gaillardoti, but there is no indication from the literature on Simosaurus that Limosaurus was ever used for it (Simosaurus was coined by von Meyer in 1842, and Simosaurus gaillardoti by von Meyer and Plieninger in 1844). I conclude that Limosaurus is, therefore, a typo.
#76 Dino
June 21, 2009

I looks like an emu!

amazing finding!

BTW have a nice father’s day, Darren!
#77 David Marjanović
June 21, 2009

Perhaps you can penetrate the language of the last one, it seems to be in German. Sauropterygian of some sort perhaps?

The last two are in German, and I confirm that it’s Simosaurus gaillardoti. So, most likely it’s indeed a typo that they copied from each other.

I don’t know what that makes it nomenclaturally.

But dilong has been found with fuzz, so why don’t we extend this to tyrannosaurs?

Because scaly skin impressions have been found that apparently belong to the tail of Tyrannosaurus. There’s not much published on them, though.
#78 Andrea Cau
June 21, 2009

How could a dinosaur be both scaly and feathered (in different ares of the body, for example, feathered in the dorsal half and scaly in the ventral one)? Is it possible or not?
…it has been suggested for Juravenator.
#79 AnJaCo
June 21, 2009

Curious that Simosaurus should become Limosaurus in [at least] 3 different places. Probably happened the way you say David, mutual copying. Oh well. Stranger things have happened…

Its still a dull name…
#80 Dr. Nick
June 21, 2009

Perhaps you can penetrate the language of the last one, it seems to be in German. Sauropterygian of some sort perhaps?

The last two are in German, and I confirm that it’s Simosaurus gaillardoti. So, most likely it’s indeed a typo that they copied from each other.

I don’t know what that makes it nomenclaturally.

Even if Limosaurus is preoccupied, “Limisaurus” (which is actually better Latin) appears to be available.
#81 Dr. Nick
June 21, 2009

How could a dinosaur be both scaly and feathered (in different ares of the body, for example, feathered in the dorsal half and scaly in the ventral one)? Is it possible or not?
…it has been suggested for Juravenator.

And, lest we forget, every living species of dinosaur has feathers on some parts of the body and scales on others.
#82 Michael Erickson
June 21, 2009

I’m a bit confused here. Even if LimOsaurus is preoccupied, why does this mean anything at all when the ceratosaur’s name is LimUsaurus? I thought that one way to get around the fact that a name is preoccupied is to change a letter, like the UltrasaurUs/UtrasaurOs deal. Since the name LimOsaurus would be the one that’s preoccupied, this should mean nothing for the validity of the (albeit very crappy) name LimUsaurus. What’s going on?
#83 Michael Erickson
June 21, 2009

Oh, and I swear I’ll shut up for a while right after I request that everyone interested in the scales/fuzz issue read comment 54. Thank you.
#84 Andrea Cau
June 21, 2009

@80, Dr Nick,
I know that. In fact, I wrote it in comment n°44.
My question was directed to those arguing that feathers and scales are mutually exclusive. How, and why? Is it true? Could they cite some study on that topic? I’m very interested.
#85 AnJaCo
June 21, 2009

Michael,
You are correct: it all has no effect whatsoever on the validity of Limusaurus. David had mentioned elsewhere that LimOsaurus would have been preferable on linguistic grounds. I brought up the possibility of preoccupation, with the implication that maybe, just maybe, the authors may have been aware of this previous usage and thus spelled it the way that they did. [I don't really know, I have not seen the paper, with any possible discussion of why they chose the spelling that they chose.]

This is all just a sidebar discussion. Which goes to David’s remark: “I don’t know what that makes it nomenclaturally.” What is the fate of a name that is originally a typo? Without a proper description and no designated type specimen, is it thus now preoccupied or is it still available for usage? I dunno. Above my pay grade…
#86 Michael Erickson
June 21, 2009

“…it all has no effect whatsoever on the validity of Limusaurus.”

I didn’t think so. Thanks!
BTW, I havn’t seen the paper either, AnJaCo. Does a PDF even exist? I could’ve swore that Darren said there was one. Did he make a mistake? And is that even possible?
#87 Christopher Taylor
June 21, 2009

Typos don’t count as published names for purposes of homonymy. So if ‘Limosaurus‘ has only appeared as a typo for something else, then the name Limosaurus would still be up for grabs.
#88 Jura
June 21, 2009

Andrea, see comment 41 for references.
#89 Jura
June 21, 2009

Dr. Nick wrote:

And, lest we forget, every living species of dinosaur has feathers on some parts of the body and scales on others.

Birds are a red herring. They only have scales develop on their tarsal metatarsal region. Scales never develop beyond this point (no body scales, no wing scales). Even when feathers are lost (like in the legs of ostriches) the scales do not replace them. Further, the scales that do exist, are able to do so only by actively repressing feather formation. Integument type seems pretty locked to epidermal formation.
#90 Steve P
June 21, 2009

Michael (C85), there is a PDF; like David said (Comment 49): you either need to fork out for it or beg someone who has it to send it to you.

Regarding the name, I’m just glad they didn’t call it Imitator…
#91 AnJaCo
June 21, 2009

Christopher Taylor, thanks for the rules clarification.
#92 Michael Erickson
June 21, 2009

Ok Steve P, thanks. I suppose there isn’t a free access PDF, then. Well, it looks like I’d better start begging. Who should I beg? Know of anybody?
#93 Steve P
June 21, 2009

Michael, is it your artwork on Epilogue? If so, is the mailing address listed as being yours correct? Loaded question, much?
#94 Michael Erickson
June 21, 2009

Has anyone here read my Comment 54 regarding the scales/fuzz issue? Three possibilities: 1) No one has, 2) They just haven’t responded to it, or 3) I got everything right and the comment can’t be argued with =;-)
#95 Michael Erickson
June 21, 2009

What’s Epilogue?
#96 Steve P
June 21, 2009

An artwork website – thought the Michael Erickson up there might’ve been you. Anyway: I have the PDF, if you want it I’ll send it to you.
#97 Michael Erickson
June 21, 2009

What’s the artwork of? Dinosaurs? I am a dinosaur artist, however I have not posted any work on the Internet. Anyway, may I PLEASE PLEASE PLEASE have the PDF? My email adress is tcmfamily@juno.com. Thank you!
#98 Eric
June 21, 2009

Here is a picture of a featherless Limusaurus for those who are interested in seeing one.

http://hodarinundu.deviantart.com/art/Limusaurus-126609548
#99 Michael Erickson
June 22, 2009

Everybody, Eric has posted a link to a picture of a featherless Limusaurus. However, don’t get too excited – It’s really no good. Sure, it’s got no feathers, but anatomically it’s only very slightly better than the cutsie “Muppet” picture in the article. It really doesn’t even look like Limusaurus. (Apoligies to the artist.) I don’t suspect we’ll get a really good life restoration until someone does a skeletal recontruction.
#100 Cameron
June 22, 2009

I thought this name looked familiar – the 2005 “World of Kong” book features a “Limusaurus” which happens to be a marine molluscivorous salamander! I’m certain there’s some Latin phrase out there to describe this prior, fictional usage
#101 Dave Howlett
June 22, 2009

@100 – this phenomenon has occurred to me. As a child I used to invent hypothetical dinosaurs, and at least two of the names I invented (Eotyrannus and Suchomimus) have later been given to real dinosaurs.
#102 Michael Erickson
June 22, 2009

Really, Dave Howlett, yoy thought up Eotyrannus and Suchomimus as a kid, before they were officially named? Dang, what a coincidence.
#103 Zach Miller
June 22, 2009

It’s not so strange. I used to do much the same thing (spec evolution) when I was a lad. I came up with all sorts of critters I would only later learn were real, including thalattosuchians (though mine were rather extreme), dicynodonts (mine had upwardly-directed flanges on the lower jaw–I don’t know why), and turtles that had flat bodies like rays (basically placodonts).
#104 Michael Erickson
June 22, 2009

Here’s a question: Does anybody know why the Bradycneme material, first identified as belonging to a giant owl, has been re-identified as non-avian theropod material? Darren has mentioned the “bradycnemids” before, but has never elaborated on the situation. If all we have to work with is the same old scrappy material, how are we juustified in saying that the original identification was wrong? I’ve noticed that people seem to always want to re-identfy any Mesozoic bird material they can as being from non-avian theropods. Like that lower jaw from a Cretaceous parrot, the one that everybody couldn’t wait to say was from a oviraptorosaur (It sure don’t like no oviraptor I’ve ever seen).
#105 Dr. Nick
June 23, 2009

@80, Dr Nick,
I know that [birds have feathers and scales on different parts of the body]. In fact, I wrote it in comment n°44.

Ah, I see now. Apologies.
#106 David Marjanović
June 23, 2009

Darren has mentioned the “bradycnemids” before, but has never elaborated on the situation.

He has… in his papers…

Like that lower jaw from a Cretaceous parrot, the one that everybody couldn’t wait to say was from a oviraptorosaur (It sure don’t like no oviraptor I’ve ever seen).

Either it’s specifically a loriid, or it’s not a psittaciform at all. The latter is much more parsimonious. Sure, it’s probably not an oviraptorosaur, but there are other options out there!
#107 David Marjanović
June 23, 2009

Those tubercles on the middle parts of the tail centra of the French Compsognathus specimen… could they be goosebumps?

Karin Peyer: A reconsideration of Compsognathus from the upper Tithonian of Canjuers, southeastern France, JVP 26(4), 879 — 896 (11 December 2006, not 2004)
#108 Michael Erickson
June 23, 2009

In which of Darren’s papers has he elaborated on why the bradycnemids are not really owls?

“…could they be goosebumps?”

Seriously though, I don’t think that they could be anything other than scales. In the rest of comment 54, I did my best to show why it would be very unlikely for Compsognathus to have a mix of feathers and scales, or to be scaly on the tail and feathered everywhere else. Let’s stop with the fluffy, Sinosauropteryx-style Compsognathus. At the very least we should leave the tail scaly in those depictions.
#109 David Marjanović
June 23, 2009

Seriously though, I don’t think that they could be anything other than scales.

Why, really?
#110 Michael Erickson
June 23, 2009

They look nearly identical to the structures seen on Juravenator* (which are most certainly scales – and the supposed “protofeather” impressions ajacent to them are definitely just muscle tissue). They also are a good match for other known theropod scale impressions. Occam’s Razor, my friend – they look like scales, smell like scales, taste like scales, they are scales.

*And if Juravenator turns out to be simply a juvenile Compsognathus, which I suspect it to be, that would probably clinch it. It would also possibly lay to rest the “babies and juveniles of scaly adult dinosaurs were fluffy” jive.
#111 Zach Miller
June 23, 2009

Juravenator may not be a compsognathid–it might be something more basal.
#112 David Marjanović
June 23, 2009

which are most certainly scales

I’ll have to look into that.

if Juravenator turns out to be simply a juvenile Compsognathus

:-/

It’s pretty different as far as I remember.

Juravenator may not be a compsognathid–it might be something more basal.

There’s good evidence for that — from Göhlich & Chiappe’s own matrix:

Richard J. Butler & Paul Upchurch: Highly incomplete taxa and the phylogenetic relationships of the theropod dinosaur Juravenator starki, JVP 27(1), 253 — 256 (12 March 2007)
#113 Michael Erickson
June 23, 2009

It is, indeed, possible that Juravenator is not a compsognathid. However, I beleive all phylogenetic analyses have returned the little guy as a compsognathid. Utill an analysis finds Juravenator more basal than the coelurosauria, I’ll treat it as a compsognathid. But regardless of what Juravenator is, Compsognathus was still scaly – the only skin impressions known show scales. Isn’t it illogical to assume that it simply MUST have had protofeathers just because its close relatives had them, especially when we have real evidence to the contary?
#114 Michael Erickson
June 23, 2009

David Marjanovic:

“It’s pretty different as far as I remember.”

Take a look at Jaime Headden’s skeletals over at DeviantArt. There’s a comparison of Juravenator and the French Compsognathus – and they look pretty similar. However, neither one looks much like the German Compsognathus specimen, which is also shown – maybe the French one IS a different species after all. But that’s off the subject.
#115 Darren Naish
June 23, 2009

I’ve spent a reasonable amount of time with Compsognathus and Juravenator (and with Sinosauropteryx, Mirischia and Aristosuchus), and there’s no way that Compsognathus and Juravenator are the same. They’re utterly different (even if they are close relatives, which is what I’ve recovered in phylogenetic work).

As for integument, we really don’t have enough evidence either way to make any confident statements about these taxa. The small bumps reported on the bones of the Canjuers Compsognathus could be just about anything (they remind me of the pathological tubercles present on some Messel bird bones) and cannot be assumed to be integumentary: they’re preserved on the bones, which makes it highly doubtful that they’re scales. Remember also that small patches of skin do not tell you about the whole of the animal’s integumentary covering.
#116 Michael Erickson
June 23, 2009

Thanks, Darren, for clearing up the Juravenator/Compsognathus deal. And I didn’t know that the “scales” were preserved ON the bones – I was under the impression that they were AROUND the bones.

“Remember also that small patches of skin do not tell you about the whole of the animal’s integumentary covering.”

I don’t know… Take a look at Jura’s Reptilian Rants blog – the post “Plucking at the Idea of Feathered Dinosaurs.”
#117 David Marjanović
June 23, 2009

It is, indeed, possible that Juravenator is not a compsognathid. However, I beleive all phylogenetic analyses have returned the little guy as a compsognathid.

No. The one I just cited, in the comment just above yours, finds it outside. It’s based on the original matrix of Göhlich & Chiappe, just with no taxa excluded from the analysis.

Utill an analysis finds Juravenator more basal than the coelurosauria

That’s not necessary (and probably not going to happen anyway).

Take a look at Jaime Headden’s skeletals over at DeviantArt.

No, I’ll take a look at the actual paper.

And I didn’t know that the “scales” were preserved ON the bones – I was under the impression that they were AROUND the bones.

Oh, so you didn’t actually see the paper? I got the impression you had it in front of you. As I wrote, the tubercles are preserved on the middle parts of the centra, but not on their proximal and distal rims, and not around the bones at all. They look like parts of the centra (…so perhaps they are the kind of pathological tubercles Darren mentioned, though that would be a great mystery).
#118 Michael Erickson
June 23, 2009

I do, indeed, have the paper, and have read it. I just forgot the actual location of the bumps – that they were preserved on the middle parts of the centra, but not on their proximial and distal rims, slipped my mind. Next time I’ll RE-read the paper, rather than having total faith in my memory of it.

“Take a look at Jaime Headden’s skeletals over at DeviantArt.”

“No, I’ll take a look at the actual paper.”

What kind of snobbish remark is that?

BTW, Darren has informed me that there’s no way that Compsognathus and Juravenator are the same, and I’m not entertaining that thought anymore. Therefore, it’s not even nessasary anymore for you to look at Headden’s skeletals comparing the two. But your refusal to even veiw them strikes me as snooty.
#119 Zach Miller
June 23, 2009

It’s not snotty at all–I’ll look at the skeleton and read the descriptors in the scientific paper before I look at a paleo-artist’s interpretation of it. No offense to Jaime Headden, Scott Hartman, etc., but this is question of primary versus peripheral sources. You would not “cite” a Headden skeletal restoration, for example.

Jaime doesn’t proclaim his skeletals to be the end-all. In fact, he often updates them based on new information, papers, and fossils. Thus, you may as well look at the primary source ANYWAY–it’s where Jaime is getting his information in the first place.
#120 Michael Erickson
June 23, 2009

Okay, maybe It wasn’t snooty after all. But it did come across that way, at least to me. The reason I wanted David to look at Jaime’s skeletals was because Jaime has a diagram that compares Juravenator and Compsognathus side-by-side – something the paper does not have. The way David’s remark came across was “Jaime Headden? Humbug, I’ll look at the actual paper – I am not going to waste my time and intellect on some idiot’s skeletal drawings.” I realize now that’s not what he meant – It is, however, how it appeared.
#121 Nathan Myers
June 23, 2009

“We all would much rather feel like “Oh, good, a Michael E. posting!” than “Oh, no, not another Michael E. posting. comment”.

Not There Yet.
#122 Michael Erickson
June 23, 2009

I’m trying to cut it down Nathan, but goodness, now I can’t even respond to comments that concern something I said? I suppose I’ll just not even get into discussions anymore. In fact, the only comments I’ll ever post will say “Hey Darren that article was cool” and I’ll never say anything different as long as I live.
#123 David Marjanović
June 24, 2009

What kind of snobbish remark is that?

Why should I remove myself one more step from the data? Why should I look at gross body shape?

After having seen the paper, I’ll be able to form an opinion on Jaime’s skeletal restorations. Judging from the rest of his work, they’re probably good, but I can’t tell without having reread the paper (…which, unfortunately, I still haven’t done).

I’m trying to cut it down Nathan, but goodness, now I can’t even respond to comments that concern something I said?

Sure you can. Just:
– try to collect everything you want to say into one comment, rather than ending up with threads where half the comments are by you;
– on the Internet, adopt a more Vulcan attitude. You come across as very emotional: overenthusiastic about interesting hypotheses, outright hostile at differences of opinion. You’ll exhaust yourself and everyone else if you continue like that.

Live long & prosper.
#124 Peter Mihalda
June 24, 2009

I cannot believe – they have found an ornithomim, and they call it a ceratosaur…
Well, this game is REALLY coming to absurdity.
Darren Naish, do not forget to delete it, please.
Sure, I may name many diagnostic features of ornithomims present in this fossil.
But is ANYBODY of this wicked crew interested in?

Peter Mihalda
#125 Peter Mihalda
June 24, 2009

Oh, Michael Taylor (No 4) is also a part of this theatre… I believed he is interested in science.
Well, I may be wrong too. And I often am, unfortunately.

Peter Mihalda
#126 Michael Erickson
June 24, 2009

David Marjanovic: Thank you for the tips. I promise I will take them to heart and do much better. My goal is to be a nice person to talk and debate with, rather than an overemotional fool, which is what, looking back over some of my comments, I’m sure I look like.

Peter Mihalda: Limusaurus is not an ornithomimosaur. You claim to have “evidence” that it is, but why should we listen to you instead of to the paleontologists who published the thing? You are not a paleontologist. You have not published. Xu Xing is a paleontologist. He has published. I shall not listen to Peter Milalda. I shall listen to Xu Xing. Limusaurus is a ceratosaur. Good day.
#127 Zach Miller
June 24, 2009

My sense is that Peter is insane (check out his last comment in the “100 Years of T.rex” post).
#128 Zach Miller
June 24, 2009

My sense is that Peter is insane (check out his last comment in the “100 Years of T.rex” post).
#129 Eric
June 24, 2009

I’ve found another picture of a scaly Limusaurus. But this one is a little harder to find.

Go here: http://channel.nationalgeographic.com/episode/dino-death-trap-2998/Overview#tab-interactive

Then, click on the 3-d dinos tab and you should get a pop-up.

You then have to drag your mouse down, eventually you’ll come to a yellow dinosaur. That limusaurus, only they call it a beaked-ceratosaur, presumably because the site came out before the information on the creature was published. This version of Limusaurus is probably my favorite.

Also if you scroll down enough you will come to a grayish dinosaur. This one doesn’t have a name either (it is referred to as a alvavrezsaur-like theropod) but I think it is highly interesting and I just thought that I should have alerted you to it.
#130 Michael Erickson
June 24, 2009

Eric: Good job finding this! But, unfortuanately, that Limusaurus is also very, very wrong. We’ll start with the legs. Its leg muscles are WAY too skinny. The feet are also too fat. Now the hands – the hands are crazy! Limusaurus had very tiny hands; the hands on that thing are HUGE! They’re also positioned wrong – its palms should face inward (medally), not downward (pronated) like a human’s. They made this mistake on the other theropods too. Another mistake is not putting feathers on Guanlong – the site was made after the discovery of feathers on other basal tyrannosaurs, so they should have known this. As for the “alverezsaur-like theropod” (not sure what its real name is), the site said that the animal possibly had fur or feathers. It did, indeed, probably have feathers, but fur is a no-no. Fur is found in mammals only. Anyway, thanks for sharing.

Zach Miller:

“My sense is that Peter is insane.”

I agree, brother. But I’m also surprised that you got away with that – I got into a bunch of trouble for calling John Jackson an “idiot”. BTW, are John and Peter twins or something? Or maybe they’re just “partners in grime”?
#131 Nick Gardner
June 28, 2009

[from Darren: sorry, delated by spam filter]

David Marjanović wrote:
There’s good evidence for that — from Göhlich & Chiappe’s own matrix:

Richard J. Butler & Paul Upchurch: Highly incomplete taxa and the phylogenetic relationships of the theropod dinosaur Juravenator starki, JVP 27(1), 253 — 256 (12 March 2007)

http://dml.cmnh.org/2007Mar/msg00164.html

As a casual reminder.

Nathan Myers wrote:
We all would much rather feel like “Oh, good, a Michael E. posting!” than “Oh, no, not another Michael E. posting. comment”.

There is an easy solution for this:
http://userscripts.org/scripts/show/4107

Michael Erickson: I am going to keep your name killfiled until your comments do not account for a worthless forty percent of a thread.

But back on the topic of Limusaurus, I agree largely with comments by Mickey and Andrea. I find it disturbing that Nature is hosting a SI that is nearly 101 pages long, when a large bulk of the pages (i.e. matrices) could have been presented separately as data files. Are the SI of papers peer-reviewed? Is it normal for the SI of a paper to have a text component that is more than five times the length of the published paper? And towards their data/commentary itself, it is no surprise to me that the results find it is more parsimonious (or at least equally parsimonious) for the hands of all theropods to be I-II-III, rather than II-III-IV. I find some of their methodology confusing, and I can see that I’ll be doing some serious lit diving on the matter.
#132 David Marjanović
June 28, 2009

As a casual reminder.

Oh, thanks. I’ll cite Mortimer 2006 along with Butler & Upchurch 2007 next time.

Are the SI of papers peer-reviewed?

Depends on the reviewers.

Is it normal for the SI of a paper to have a text component that is more than five times the length of the published paper?

In Nature and Science these days, yes. And my next paper, recently accepted by Evolutionary Biology, has a supp. inf. which was added at the request of a reviewer and is basically a paper of its own.
#133 Michael Erickson
June 28, 2009

“I’m going to keep your name killfiled until your comments do not account for a worthless forty percent of a thread.”

Huh? What’s all that mean?
#134 Nick Gardner
June 28, 2009

@C133/Michael Erickson: If you had bothered to read my post (and followed the links) before sending a response, you would understand. Basically, it means all of your comments currently appear as “Comment by Michael Erickson blocked”.
#135 Michael Erickson
June 28, 2009

Okay. But why block my comments? I have done nothing.
#136 Nick Gardner
June 28, 2009

Peter wrote:
“I cannot believe – they have found an ornithomim, and they call it a ceratosaur…
Well, this game is REALLY coming to absurdity.
Darren Naish, do not forget to delete it, please.
Sure, I may name many diagnostic features of ornithomims present in this fossil.
But is ANYBODY of this wicked crew interested in?”

Peter, I would not object. Please feel free to contact me through email.
#137 Michael Erickson
June 28, 2009

Why are you blocking my comments when I have done nothing wrong?
#138 Daniella Perea
June 28, 2009

Michael: seriously, I am begging you, PLEASE cut down on the comments. PLEASE. You are dominating the comments here.
#139 Nathan Myers
June 28, 2009

M.E.: Not. There. Yet.

Nick doesn’t care to see any more of your comments, so he arranged not to see them. That’s all. He even explained why he arranged it. Please go back and re-read all the advice you have been given, and learn. Also, please do not reply to this posting.
#140 Michael Erickson
June 28, 2009

I know you asked me not to reply, but can’t I at least apologize?
#141 Nathan Myers
June 28, 2009

You are really, really not getting this, are you? No. The rest of us do not need to learn of your inner thoughts. We have inner thoughts of our own that we are polite enough not to bother others with. Can you be polite enough to spare us your inner thoughts? (That was a rhetorical question, meant to provoke thought, not another posting.)

Please stay away for at least a week — no postings at all — to think over your problem, and to re-read and contemplate the advice you have been offered. If you’re not entirely certain you understand completely, stay away another week. Repeat.
#142 Miss Manners
June 28, 2009

When it has been hinted that one is speaking too much, and then asserted outright that one is speaking too much, and one is then asked to not speak after having spoken too much, then speaking, even if it is an apology, is in fact not appropriate.

Finger to the lips.

Rather than stay away for a week, I would recommend limiting comments to one per thread per twenty-four-hour period. This will both limit the number of comments and allow you to gather everything you want to say in one large comment, which can be perused in a far more efficient manner. Open a text file, and add to it everything you might want to say. This will also allow you to edit it down before posting it, if, on a careful re-read, something looks a little too off-topic. Does this make sense?

If one still desires to chat, it might be worth pointing out that there are far more chatty places for chatting than the tetrapod zoo.
#143 Michael Erickson
June 28, 2009

I will be quiet after I say this. You all have the problems, not me. I comment way too much. Okay… I have cut it down consdiderably since this thread, or have you not noticed that on the latest thread only 4 out of 20 comments are mine? I’d hardly call that dominating the comments. And I’m working on cutting it down even more. I don’t get why you all have to be so friggin’ rude. You can’t even accept an apology? Besides, it’s Darren’s blog. It’s not your place to tell me to shut up – only Darren can do that. And anyway, I live in AMERICA. America is a free country – I do not have to cut my comments down any bit at all, but I am doing so out of curtesy. Also, this is a science blog, and I ask serious science questions and discuss serious science topics. I am not a troll or a Peter Mihalda. I also find it very insulting that someone on the latest thread asked me how old I was, and said that they sensed “fan-boy syndrome.” This rudeness is completely, ridiculously out of hand. I’ve never seen so much rudeness in one place. I think you all have issues to work out. P.S. I am not checking back on this thread, so you might as well not even respond – all you’ll be doing is wasting your own time. Good Day.
#144 Peter Mihalda
June 29, 2009

Thanx David for sending me supplementary data.
Well, this only shows I was right. The cladogram is, as always, very wrong. How can Sinraptor, with 4 manual digits and many many plesiomorphies listed by Currie and ?Dong, 1993, be higher than Allosaurus? To have 4 manual digits is PRETTY normal for theropods, and I am very glad they have showed Coelophysis Fig 3Sb with 5 digits.
There are some persons who ONLY insult and attack others, without having knowledge. Like Darren Naish, who claimed before that manual digit formula is diagnostic for Theropoda, and I am a fool and an idiot. O.K. if he feels fine, he may target me, but as I said before
HE CANNOT STOP THE TRUTH.
Never forget this. The most people of this list, and those whom you call “professionals” are grossly infamiliar with an object of study, and literature, and when someone points out their errors, they simply hide behind some stupid, incredible, even kindergarden excuses, how they are perfect and professional and I do not know what else.
I remember when they have challenged Feduccia to come and face facts, all right ask me and I shall demonstrate BASED ON SOLID SCIENTIFIC DATA that Dinosauria as defined today is not a monophyletic group.
Eoraptor is STILL kept in Saurischia, without hyposphene-hypantrum and laminae on dorsal neural arches. This is an OPEN lie.
I may continue but shall not to waste my energy. And those who want to target me -
“Hold me – thrill me, kiss me – kill me”
Violence, that is their method. And threats. GOOD luck.

To Michael Erickson – America is a free country? I regret you. You are completely out of informations.

Peter Mihalda
#145 Darren Naish
June 29, 2009

I don’t need to make a fool of you: you are an expert at doing that yourself. On the hand of Coelophysis, maybe it’s time you learnt that a metacarpal is not the same thing as a digit.

By the way, it’s a hallmark of the lunatic fringe that they rant and rave on other people’s websites, only ever saying negative things and proclaiming that everything in the ‘mainstream’ is wrong. What’s it like to be a fringe lunatic? I imagine it must be frustrating, knowing that no-one takes you seriously.

One more negative comment and I will start deleting your messages again.
#146 David Marjanović
June 29, 2009

Thanx David for sending me supplementary data.

So you admit to having talked about stuff you had not even read yet.

Telling.

Sinraptor, with 4 manual digits

Metacarpals, not digits.

Yes, I know some people misuse the term. Don’t let that confuse you.

higher than Allosaurus?

“Say never higher or lower” – Charles Darwin, 1844

Allosaurus and the coelurosaurs lost the (already strongly reduced) 4th metacarpal several times independently. The strong reduction of that metacarpal, on the other hand, is an autapomorphy of Tetanurae.

Eoraptor is STILL kept in Saurischia, without hyposphene-hypantrum and laminae on dorsal neural arches. This is an OPEN lie.

It’s being redescribed. Wait for the paper.

Violence, that is their method.

Banning you from a blog is “violence”? ROTFL!
#147 Kryptos18
July 1, 2009

http://ntamura.deviantart.com/art/Limusaurus-126449519

This is my favorite reconstruction of Limusaurus so far. Featherless, tiny-armed, and full of basal-ceratosaurian glory! It may not be perfect, but it’s a hell of a lot better than that gaudy thing they’ve been showing on all the news sites…
#148 David Marjanović
July 1, 2009

Beautiful. Just the leg proportions look wrong.
#149 Zach Miller
July 1, 2009

Rescription of Eoraptor, David? Exciting.

Peter talks like Fawful in Mario & Luigi: Superstar Saga. I HAVE FURY!
#150 Peter Mihalda
July 1, 2009

WARNING: FRINGE LUNACY, NOT TO BE TAKEN SERIOUSLY (all Peter Mihalda messages will now come with a health warning)
——————————-

Yes, four digits mean there are 4 metacarpals, of course. How can you call that extremity which is a metacarpal but does not have other, more dital portions of that digit?
I do not NEED to wait for a redescription of Eoraptor – me I have personally observed its cast, in detail, and have good photos of that (2 casts presented side by side). Both EXTREMELY broad metatarsals, UNABLE to be carried in upright position, relative to digits, or toes (for dumber ones).
There are many other things why it is not a saurischian, I may name them.

This taxon we are speaking about is a theropod, and that way a ceratosaur (as Ceratosaurus is the first known theropod) but then their clade is called Ornithomimosauria, because ornithomims are GOOD theropods, and thus you may call it derived ceratosaurs. BTW, Ceratosauria as defined now is not monophyletic.

My dear Darren, I am not raving, am very calm, because I know I am much closer to the truth than you are. Many people take me seriously, of course not of your crew ( would I expect that? That liars may agree with one who is speaking about the truth?), and of course you may delete anything, it is your blog. I only joined because English (unfortunately!) also means “European”, but now I see you are much closer to U.S.A., as one actor already sung about. Again, your choice. You see – I am not threating, as opposed to you.
And to that fool (or a liar) I may only address the same – if “America” (he probably menat U.S.A.) is a free country, then voice your opinion, something against the government. If you give me your address of jail, I shall send you apples from my farm.

Peter Mihalda

——————————-
WARNING: FRINGE LUNACY, NOT TO BE TAKEN SERIOUSLY (all Peter Mihalda messages will now come with a health warning)
#151 Darren Naish
July 1, 2009

The above might seem like a nasty thing to do, but I feel it’s necessary in order to try and minimise the spread of misinformation being promoted by this individual. We are dealing with someone who honestly thinks that phylogenetics can be done by looking superficially at (literally) one or two characters.
#152 I. M. Anonymous
July 1, 2009

I don’t think Peter Mihalda needs any sort of labeling. He labels himself (e.g. with ALL CAPS assertions), and posts infrequently enough that his ravings serve mainly as an example of how to recognize bad reasoning, and the measured responses illustrate sound responses to bad reasoning. (Likewise, in Jackson’s case.)

The real threat is Michael Erickson, who has single-handedly reduced the pleasure one can get from following TetZoo comments in a way no loon has managed. I’ve addressed it locally with Firefox/Greasemonkey, but that only helps me. I guess the posting-frequency filter has helped some, but it’s the sheer thoughtlessness of his comments that makes them so annoying. That’s hard to filter for.
#153 David Marjanović
July 1, 2009

Yes, four digits mean there are 4 metacarpals, of course.

But not the other way around!

How can you call that extremity which is a metacarpal but does not have other, more dital portions of that digit?

I call it… a metacarpal…

Big surprise there, eh?

I have personally observed its cast, in detail

How detailed is the cast itself…? And I think there’s new material, too.

Ceratosauria as defined now is not monophyletic.

As defined now, this name cannot help applying to a monophylum, not even in theory. Look, here’s the definition: “all organisms more closely related to the type specimen of Ceratosaurus nasicornis than to that of Passer domesticus“.

There are many other things why it is not a saurischian, I may name them.

Publish them.
#154 Michael Erickson
July 2, 2009

I AM SICK AND TIRED OF BEING TREATED LIKE CRAP FOR POSTING TOO OFTEN. THERE IS NO LIMIT ON HOW MANY COMMENTS THAT CAN BE POSTED ON TET ZOO – THEREFORE I AM NOT TAKING UP SPACE FROM OTHER PEOPLE. I AM SICK OF THE ATTACKS. THERE ARE ONLY SO MANY ATTACKS ONE PERSON CAN TAKE. I AM SICK OF HAVING PEOPLE BLOCKING MY COMMENTS FROM THEIR SIGHT LIKE I’M SOME KIND OF MONSTER. I APOLOGIZE FOR THE ALL-CAPS ASSERTIONS, BUT I AM ONLY A HUMAN BEING AND I CAN’T HANDLE THE SENSELESS ABUSE ANYMORE. THE VAST MAJORITY OF MY POSTINGS ARE SERIOUS SCIENTIFIC QUESTIONS, INQUIRIES AND COMMENTS. IT’S NOT LIKE I’M SOME SORT OF LOON LIKE PETER MIHALDA OR JOHN JACKSON. WHAT IS EVERYBODY’S PROBLEM? THIS IS ENOUGH. THE RUDENESS, THE MEANNESS, THE ABUSE, IT MUST END. I HAVE FEELINGS TOO. I AM NO THREAT TO ANYONE. I HAVE JUST AS MUCH RIGHT TO BE HERE AS ANYONE ELSE. I AM SICK OF THIS!!!!!!!!! AGAIN I APOLOGIZE FOR THE ALL-CAPS, BUT I DON’T KNOW WHAT ELSE TO DO. I CAN’T HANDLE THE ABUSE ANY LONGER.
#155 Nathan Myers
July 2, 2009

Michael/Bonnie: None of us has a right to post here; we are all here as guests, on Darren’s sufferance. (Darren is not, incidentally, American.) If you came to a party at Darren’s house and pissed on the rug, you would be asked, with increasing urgency, to stop, before being ejected. Same here.

Your feelings of persecution are undoubtedly keenly felt, but there is nothing we can do for them. Please seek immediate professional medical help. Seriously. The modern pharmacopoeia might well have just what you need.
#156 Michael Erickson
July 2, 2009

Who is Bonnie? What are you talking about?
#157 Connie Sue Erickson
July 2, 2009

Nathan Myers, My son is Michael Erickson. He is highly upset over your earlier comments. You see, he is just a child. A child with vast knowledge, but a child. I hope this explains things. Now that you know the situation, I am sure that it will be worked out. After all, who in the scientific community wants to loose a mind full of knowledge like he has at such a young age. Thank you
#158 Peter Mihalda
July 8, 2009

WARNING: FRINGE LUNACY, NOT TO BE TAKEN SERIOUSLY (all Peter Mihalda messages will now come with a health warning)
——————————-
Yes, I do not read those articles. A waste of my valuable time. I look at the fossil, and see what it is. Now I saw they have compared manual formulae of many clades. Good. But a very bad news – manual formula is NOT diagnostic even in EXTREMELY related forms. Here,s an example: Indian and African elephants, 5/4 vs 4/3 manus/pes.
Here we go to another issue Darren Naish tried to question: what is incorrect, that Coelophysis has a 5-dactyl manus? It is photographed! And here nicely shown Sereno,s nonsenses about a reduction of theropod formula! Digit IV has 3 phalanges and an ungual (claw), and V still has a phalanx. And Darren Naish, because of his considerable ignorance, does not know that Teratosaurus? minor Huene, 1907 does not have a phalanx on its digit V, so is more reduced than theropods! BTW, Sauropodomorpha is wrongly defined by Ezcurra (2006) Saturnalia+Plateosaurus, since it technically means Prosauropoda+Segnosauria, because Plateosaurus is an animal leading to segnosaurs. Here the formula is somehow diagnostic because one of a very few synapomorphies of Sauropoda is their manus, and segnosaurs have only 3 digits (but I believe they will find some early member with 4). So Sauropodomorpha should be Saturnalia+Camarasaurus.
Theropoda is not monophyletic unless you count forms with a cleft on the lesser trochanter (Limusaurus has it, or only a wing like Ceratosaurus?).
I apologize to Mrs Erickson, I just thought her son is another US provocateur. Sorry baby.

Peter
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WARNING: FRINGE LUNACY, NOT TO BE TAKEN SERIOUSLY (all Peter Mihalda messages will now come with a health warning)
#159 Peter Mihalda
July 8, 2009

WARNING: FRINGE LUNACY, NOT TO BE TAKEN SERIOUSLY (all Peter Mihalda messages will now come with a health warning)
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Dr. Naish is not any specialist in psychiatry, yet he diagnose people for a long distance. I would say he is not any doctor, looking at his weak “work” (those few articles).
To others I may say – do not listen to those who lie, or are “out”, it is just a final stage of their agony.
Everyone who is “in” must agree that my scheme is much more probable.

Peter Mihalda
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WARNING: FRINGE LUNACY, NOT TO BE TAKEN SERIOUSLY (all Peter Mihalda messages will now come with a health warning)
#160 Peter Mihalda
July 8, 2009

WARNING: FRINGE LUNACY, NOT TO BE TAKEN SERIOUSLY (all Peter Mihalda messages will now come with a health warning)
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To Myers: ME I have THE right to post here, because it is a topic I may say much about, and second it is a PUBLIC forum. Without people corresponding here dear Darren may write to himself, like Mr Bean. Not to say I have a strong feeling he does many things on purpose (eg misinforming people).
And to baby Erickson – do not be sad about fools and wicked people, it is the only thing they can do, because they have nothing to say scientifically.
And come back home, to EUROPE!
Darren Naish is really not American, but he acts like one of them. No wonder – they have already lost their identity, they watch US films, they speak like Yanks, and they THINK like Yanks. He should be awarded in Washington by “his” president Obama (=warmonger), for his contribution to U.S. “science”.

Peter Mihalda
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WARNING: FRINGE LUNACY, NOT TO BE TAKEN SERIOUSLY (all Peter Mihalda messages will now come with a health warning)
#161 johannes
July 8, 2009

> they speak like Yanks

Er, people in England were speaking English since the Saxon invasions of the fifth century, some 1300 years before the US even existed, so Hollywood movies are hardly to blame here. The fact that the language we use here is called ENGLISH should had been a hint for you ;D.
BTW, what is the source of your, er, remarkable, political views? Stormfront? Barbarossa Publishing? Dieudonne M’Bala M’Bala? Jürgen Elsässer? Pierre Guillaume?
#162 Zach Miller
July 8, 2009

Yes, “segnosaurs” (who uses that term anymore?) are derived prosauropods. Falcarius and Beipaiosaurus say nothing of a theropod ancestry. Why am I even responding to this bait?
#163 Peter Mihalda
July 13, 2009

WARNING: FRINGE LUNACY, NOT TO BE TAKEN SERIOUSLY (all Peter Mihalda messages will now come with a health warning)
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Yes, everywhere wanna-gonna, very English… BTW, English who live here in Europe speak good English, and when I asked why they left England, the answer is almost always the same: headache. Nausea. Vomitting. After all, you will be sink very very soon, by your own stupidity. The only “advantage” you have is that you may call yourself “English” and those who will liquidate you are just “British”.
My views reality wrote.

Now to saurischians. Zach Miller, certainly an expert on these animals, surely missed the second paper on Beipiaosaurus, showing its sauropod-like ilium (and a non-existent pygostyle). I ask you – show me ONE, only one, theropod with an ilium like that.
Segnosaurs are used because Segnosaurus has been described in 1979, like Nanshiungosaurus, but the latter was referred to sauropods. Therizinosaurus Maleev, 1954 are just claws.
What about Falcarius? It is a derived prosauropod, and you find its skeleton online. The skull is, however, reconstructed too big.
But this is still nothing what I want to say, if prosauropods or derived rauisuchids (=theropods) still only saurischians. I show you who makes a GREAT fool of himself. His name is Carpenter, and here you may see “the lie in action”
https://scientists.dmns.org/sites/kencarpenter/PDFs%20of%20publications/Hesperosaurus.pdf
Fig 3.4.F the bone below the postorbital is nothing else than the postfrontal, diagnosed to be absent in dinosaurs. Maryanska 1977 also showed it on a juvenile ankylosaur.
Still believe in your fairytale? So sleep tight, my baby, and do not use your mind, WE think for you, and then tell you how it is

Peter Mihalda
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WARNING: FRINGE LUNACY, NOT TO BE TAKEN SERIOUSLY (all Peter Mihalda messages will now come with a health warning)
#164 Crash Peck
August 1, 2009

Why did you people even discussed a HodariNundu’s drawing here? Had you bothered to see through his gallery you would have seen that he is not a paleo-artist, he does draws a lot of dinos but he like re-designs them. I don´t see why anyone would take a drawing of this kid and discuss it as if it was serious paleo-art (with all due respect to the guy, of course).
#165 David Marjanović
August 3, 2009

Yes, I do not read those articles. A waste of my valuable time.

You deliberately try to stay ignorant? That explains something.

ME I have THE right to post here, because it is a topic I may say much about, and second it is a PUBLIC forum.

Bullshit. This here is a blog. It’s the private property of Darren Naish and Seed Magazine.

(This is also something that Michael Erickson needs to learn: you are not in America here, you’re on the Internet.)

Yes, everywhere wanna-gonna, very English…

That’s the difference between spoken English and written English, o ignoramus. What you’re talking about is that Americans are, on average, more comfortable with writing the way they speak.

On the other hand, no native speaker of English or any other language that has articles would ever say “I have THE right to post here”. Try emphasising “have” or “right” next time.

Read more, and think about why people wrote what they did. This way you’ll learn how to use articles. There is no other way.

Fig 3.4.F the bone below the postorbital is nothing else than the postfrontal, diagnosed to be absent in dinosaurs. Maryanska 1977 also showed it on a juvenile ankylosaur.

That was a misinterpreted palpebral. As usual, you don’t know what happened in the last 32 years.
#166 Darren Naish
August 3, 2009

Note: racist moron ‘Peter Mihalda’ is banned for life. He still submits comments, but they’re all filtered away and safely deleted before anyone gets to read them.
#167 DDeden
August 3, 2009

@ 47 Steve, “I would think that no known post-Mesozoic birds attained large enough sizes to warrant loss of feathers”, did you see the news on the little songbird in Laos with a bald head?
#168 Terry Hunt
August 3, 2009

Perhaps not relevant to the wider context of Steve’s observation, DDeden. Steve was discussing a possible analogy between loss of feathers in previously feathered dinosaur lineages and large mammal lineages’ whole-body losses of fur as an aid to thermoregulation (and/or adaptation to an aquatic habitat, presumably). We already know that feathered theropods can lose feathers in favour of baldness for other reasons in selected body areas, to wit, the heads and upper necks of vultures; to avoid serious feather soiling when delving into the body cavities of corpses, it was assumed. This new Laotian songbird is certainly intriguing in that it has a very similar loss pattern but presumably does not feed like a vulture!

On Steve’s proposed feather-loss-by-reversion-to-scales scenario, I wonder (rather late in the day, I admit) if this could actually be investigated by selectively breeding chickens with an eye to varying areas of their leg integument between all feathers, intermixed feathers and scales, and all scales (or even feathery scales)? If Charles D could gain evolutionary insights by breeding pigeons. maybe Steve P could emulate him.
#169 Cameron
August 3, 2009

Terry,

Among the aegypiine vultures it is notable that Gyps is the messiest feeder but only Torgos and Sarcogyps are completely bald. Also interesting is that giant petrels can get extremely gory at carcasses but don’t seem to have any trouble washing off their fully feathered heads. It would be interesting to test the effectiveness of baldness as a means to prevent soiling (how? I’m not sure…); but considering the temperature extremes the birds have to deal with it seems much more likely that baldness is almost or entirely an adaptation for thermoregulation in vultures. In case you haven’t seen it already:

Ward, Jennifer P., et al. 2008. Why do vultures have bald heads? The role of postural adjustment and bare skin areas in thermoregulation. Journal of Thermal Biology 33, 168-173

While a lot of large birds have partially lost their feathers it really isn’t obvious why a (presumably tiny) songbird would – except as some bizarre form of display.
#170 Dartian
August 4, 2009

Cameron:

While a lot of large birds have partially lost their feathers it really isn’t obvious why a (presumably tiny) songbird would – except as some bizarre form of display.

According to Woxvold et al. (2009), the bare-faced bulbul Pycnonotus hualon is about 20 cm long (i.e., about the same length as a wood thrush Hylocichla mustelina). As for other bald-headed/bald-faced passerines, there are a few. For instance, the friarbirds Philemon, the rockfowl Picathartes, and the capuchinbird Perissocephalus tricolor. But I don’t know whether these taxa share any particular biological characteristics that could explain their baldness.

Reference:

Woxvold, I.A., Duckworth, J.W. & Timmins, R.J. 2009. An unusual new bulbul (Passeriformes: Pycnonotidae) from the limestone karst of Lao PDR. Forktail 25, 1-12.
#171 Brian
August 4, 2009

Regarding bald-headed passerines, there’s also Picathartes. Exactly why these cave-frequenting insectivores are bald isn’t clear to me. Perhaps the striking patterns of their heads make recognising each other in the dark of caves and shaded rainforest easier.

Then there’s the Bornean Bristlehead (Ptyriasis, if I’m not mistaken) This passerine has one big head and I believe it is largely bald. I have no idea why it’s bald-headed.

I believe there also exist bald cotingas.

Parrots offer a few examples too: Pyrilia vulturina and Pyrilia aurantiocephala have completely bald heads as adults. This is probably related to messy feeding on fruit. The other members of their genus have normally feathered heads (though rather strikingly coloured ones, which also happens to be the case with the ‘baldies’. Vulturina has a black and yellow head, while aurantiocephala’s is orange/yellow.)
The most bizarre are perhaps the vasa parrots (Coracopsis) as these have seasonally bald heads. During the mating season these birds lose the feathers on the head and their naked skin grows yellow. During this time they also have externally visible genitalia. Given that they also tend to be polygamous these birds have a bizarre sex life, as parrots go.
#172 DDeden
August 4, 2009

I hadn’t known that baldness in small birds was so common. The bald parrots and the feather-headed kin remind me of the NW monkey bald headed Uakaris, I think they’re Amazon canopy frugivores. I recall the penguin which suffered from complete feather loss, the zookeepers provided a wetsuit which worked adequately. BTW there’s an article about bacteria which eats feathers, IIRC there’s a blue bird with toxic feathers and preening oil, so there may be an interspecific arms race in feather retention (more so in very hot areas?). I’m confused why feather coloration can be of either (generally toxic?) pigment or structural color, but I guess related to sociality of species in environment (regarding bacterial contagion) and niche. Bird lower legs have scaly skin, but I thought that was more like our knuckles with folds/wrinkles than actual scales, allowing extension beyond normal taut skin, for running/hopping, in addition to prevention of algal flotsam and dirt from coagulating on the feathers, as well as thermoregulation (snowbirds have thick feathered legs, ostriches don’t).
#173 Zach Miller
August 4, 2009

I will miss Peter’s insane, hate-filled rants. He’s really the Mike Adams of paleontology.
#174 LeeB
August 4, 2009

Wilson’s bird of paradise Cincinnurus respublica has a weird bald blue head with a black cross on it in both sexes.
It looks like there are a number of small tropical birds with bald heads for species or sexual recognition purposes.
Outside the tropics they would probably lose too much heat for this to be viable, at least in winter.

LeeB.
#175 Jean-Pierre D'Amour
September 4, 2009

Deleted.
#176 Alexander Vargas
October 6, 2009

Vargas, AO, Wagner GP, and Gauthier, JA. Limusaurus and bird digit identity. hdl.handle.net/10101/npre.2009.3828.1

Here is our response to the Limusaurus paper. It was recently rejected by nature, not for any technical reason but because it was considered not to be of sufficient interest/importance.

We have uploaded it at the nature precedings citable archive, because we think it is important there is a quick and citable reply that unlike Xu’s proposal, is consistent with the view of the larger community of theropod paleontologists, namely, that tetanuran digits still are I, II, III. We are preparing a longer paper on this topic.
#177 Thomas R. Holtz, Jr.
October 6, 2009

Alexander (comment #176):
I am certainly more favorable to the hypothesis you, Gunther & Jacques propose than the initial Xu et al. explanation, and look forward to your longer paper.
#178 Darren Naish
October 6, 2009

If the link given above doesn’t work, use this one. Thanks, Alexander, for posting this here.
#179 David Marjanović
October 6, 2009

I just sent the link to the DML and will read the paper ASAP.
#180 Mario
February 11, 2011

Hmm, i wonder mr.naish could it be possible that deltadromeus was in fact a very primitive and one of the first noasaurids ?? Thus he had many primitive features ?? but deltadromeus foot also das features present in Masiakasaurus. Or is that impossible.