Tetrapod Zoology

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I’m now leaving, again, this time for SVPCA. I’m hoping that I might be able to do some blogging from the conference, but the last time I said this (the Munich Flugsaurier conference back in September 2007) there was neither the time nor opportunity for it, so don’t get your hopes up. Thanks to SVPCA and other matters, I’ve obviously been unable to put anything substantial on the blog for a while now… making Tet Zoo all too much like a normal blog… and for personal (family-related) reasons, it’s been a strange and sad week here. We’re all in need of time off that we can’t afford to take. Apologies to those awaiting email responses, please hang in there.

Anyway: what’s with the pictures I hear you ask? My original intention for SVPCA was to discuss the functional morphology and feeding behaviour of waterbirds but, for various reasons, that hasn’t panned out and instead I’m going to be discussing the azhdarchid research that Mark and I published recently (Witton & Naish 2008). It has, however, given me an opportunity to throw together various thoughts on waterbird anatomy and behaviour, all of which will be covered here at Tet Zoo in due time. You might, or might not, be staggered to know how little work has been done on such things as heron morphology and function. Personally I love the fact that herons can catch and eat snakes, rodents, moles, ducklings, doves and bunnies as shown here: these images come from a sequence where a Grey heron Ardea cinerea caught, drowned, and swallowed a rabbit. I thought these images so cool I showed them to Will, but he didn’t share my enthusiasm (he’s 6).

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The photos aren’t new: they first appeared online in 2006 and were taken in June 2006, in The Netherlands, by photographer Ad Sprang. The heron caught the rabbit by the ear and flew off with it, with the rabbit shrieking and wriggling all the while. The rabbit was then drowned and swallowed whole.

Thanks to those who have provided support, see you on the other side.

Ref – -

Witton, M. P. & Naish, D. 2008. A reappraisal of azhdarchid pterosaur functional morphology and paleoecology. PLoS ONE 3 (5): e2271. doi:10.1371/journal.pone.0002271

Comments

  1. #1 Kilian Hekhuis
    September 1, 2008

    Appearently, the heron had specialized in eating rabbits, as he was caught a few days later for a second time: http://www.buiten-beeld.nl/nederlands/search/?search%5Bsearch_word%5D=reiger+konijn

  2. #2 Wilbert
    September 1, 2008

    First of all I’m sorry to hear that you had a bad time the past week. Everone goes through these things and it never seems to get any easier.

    And on the subject of herons.
    Does anybody know more of the enigmatic Easter island heron, (other newly found recent subfossil herons like the Bermuda night-heron ,the Ascension island night-heron and the night-herons of the Mascarenes are a bit less obscure but any information is welcome)

    I wonder why there seem to be no subfosisl remains of (flightless) species of Nycticorax on the pacific isles.

  3. #3 Wilbert
    September 1, 2008

    Another amazing thing about herons is their long evolutionary life-span. A Nycticorax fossil is found in the Early oligocene of Fayum so this particular genus exists for at least 34 million years. The turnover rate in birds is apparently quite different than in mammals.

    I’m also curious about the intelligence of these demonic herons. To catch yourself a cuddly lagomorphian snack by the ear, fly away with it, drown it somewhere else and gulp it down shows a high level of intelligence (at least to me).

  4. #4 David Marjanovi?
    September 1, 2008

    The turnover rate in birds is apparently quite different than in mammals.

    It’s not as if “genus” had a definition, though.

  5. #5 Mike from Ottawa
    September 1, 2008

    And here’s me having been thrilled to watch a perch slide down the throat of a local great blue heron last week. Actually, it was really cool to watch the lump slide down, plus a perch doesn’t have the cuteness factor of a bunny rabbit. Clearly what’s needed now is for Mark to do a series of Quetzalcoatlus pics showing the ‘monster stork’ swallowing a dino and the lump moving down its throat.

    As for posting rate, please don’t apologize. You’ve got to maintain yourself by attention to your family and attendance at things like SVPCA or you might not be the enthusiastic and genial host you are.

  6. #6 Wilbert
    September 1, 2008

    On the other hand it could be that this meek gentle heron was just trying to defend itself against a voracious serial-killer-rabit who accidently impaled itself on the poor heron’s bill.

    (ps.david Marjanovic, I don’t grasp your meaning I’m afraid. “it’s not as if “genus” had a definition though ?”

  7. #7 kereng
    September 1, 2008

    Ad_Sprang_2006_heron_photo.jpg is not a good name for a picture because it gets blocked by adblock in Firefox (with a quite usual configuration).

    Have you heard of the heron that took a piece of bread when the ducks were fed, but didn’t eat it. It put the bread on the water and waited for a fish. It was shown in TV and looked credible.

  8. #8 Darren Naish
    September 1, 2008

    Thanks for comments. Easter Island heron: virtually nothing is known about it, it’s known only from a fragment of synsacrum which – according to David Steadman’s Extinction and Biogeography of Tropical Pacific Birds (2006) – is similar to that of Egretta… though note that he seemed to be using Egretta in the ‘traditional’, inclusive sense rather than in the revised sense used by Sheldon et al. (2000). Where is Tommy Tyrberg? He will know more.

    Ref – -

    Sheldon, F. H., Jones, C. E. & McCracken, K. G. 2000. Relative patterns and rates of evolution in heron nuclear and mitochondrial DNA. Molecular and Biological Evolution 17, 437-450.

  9. #9 Darren Naish
    September 1, 2008

    Have you heard of the heron that took a piece of bread when the ducks were fed, but didn’t eat it. It put the bread on the water and waited for a fish. It was shown in TV and looked credible.

    Use of bait to attract fish is actually pretty common in herons and has been recorded in night herons and ardeine herons, most famously in striated herons Butorides striata (incidentally, killer whales will use bait to attract birds).

  10. #10 Mike from Ottawa
    September 1, 2008

    Use of bait to attract fish is actually pretty common in herons and has been recorded in night herons and ardeine herons, most famously in striated herons Butorides striata (incidentally, killer whales will use bait to attract birds).

    Now that’s why TetZoo is best blog (and thanks to kereng for bringing this up). That is just so cool.

    Of course, now I have to go hunt for info on this. TetZoo: the blog with homework.

  11. #11 Vasha
    September 1, 2008

    Wilbert — Suppose you have a bird species and a mammal species both living 30 million years ago. Suppose both of them have 30 descendent species living nowadays. Possibly, bird systematists could assign all the descendent species and the ancestor to one genus. And mammal systematists could divide the modern mammal species into 3 genera and assign the ancestor to a fourth. These would both be legitimate things to do because there’s no definition of “genus”. Then you could exclaim “Wow, the bird genus has been around for 30 million years!” No, actually, the situation here is exactly the same in the birds and the mammals, it’s just a difference in use of terminology.

  12. #12 Wilbert
    September 1, 2008

    Thanks Vasha
    So it’s all a ‘scientific’ matter of whim and fashion ? When transcends a species into another species.
    Everything is in turmoil, old genera are getting obsolete (or dragged out of their dungeons) at an neck-breaking speed nowadays.

    I think most of the ‘scientists’ like to live easy, relax and talk endlessly about tiny (political/social) details (did man kill the Malagassy giant lemurs or some unknown force (read: bad weather) etc..)
    Everyone knows the truth.
    Even the unbelievers.
    But most zombies don’t seem to care.
    (don’t get me wrong I also like a good chat with mates and a nice bacchanal but that’s not the point)

    Even when some ‘scientist’ would find a unlucky diprotodon with ninety spears sticking out of it’s skull and ars they would blame it on the unpredictable summer 40.000 years BC (in November)

    In general I find the progress breath-taking slow.
    Were we rabbits we would be an easy meal for Ardeo cum suis.

  13. #13 Neil
    September 1, 2008

    The whole herons taking bread thing is amazing to watch. Mind you the ones in regents park tend to just eat it! As you can see from this one there not fond of sharing! http://flickr.com/photos/ukwildlife/2279719229/
    These guys are so tame you can walk right up to them, and the youngsters just ignore live fish the parents bring in from the thames, in favour of the pilchards and bread people give to the adults most the time, with the unfortunate result of lots of starving juveniles after they fledge.
    Incidently Ive seen a photo of the a Regents park (Grey) herons catching and eating a starling!

  14. #14 David Marjanovi?
    September 1, 2008

    So it’s all a ‘scientific’ matter of whim and fashion ? When transcends a species into another species.

    The term “species” has around 25 different definitions. The term “genus” has 0 definitions. (Well, OK, there’s one that’s occasionally proposed, but it’s almost never applicable, and — like most definitions of “species” — never to fossils.) I predict the term “genus” will largely fall out of use over the next decades.

    You can declare anything a genus, and you’re never wrong.

  15. #15 Stevo Darkly
    September 1, 2008

    Darren, sorry to hear you’ve had a bad week. I hope things get better. And enjoy SVPCA.

    In Predatory Dinosaurs of the World, I believe Greg Paul mentions seeing a film of a large heron hunkering down on its “hocks” — that is, assuming a plantigrade posture — in order to stalk (and presumably capture) a dove. Although that’s not as cool/creepy as predating on a rabbit.

  16. #16 Rob Jase
    September 1, 2008

    Everyone is tslking about the heron? Here we have a new cryptid, the first known aquatic rabbit, discovered by pure chance and its being ignored.

    Does anyone know if there are any photos of herons catching sasquatches?

  17. #17 Jerzy
    September 1, 2008

    BTW, tame herons apparently have a habit of pecking at owners eyes. So, don’t come too close.

    Interesting question – how big prey could pterosaur swallow? Did they have crop to dissolve extra-large food items?

  18. #18 Mark Lees
    September 2, 2008

    Several years ago while birdwatching at a local nature reserve I saw a heron apparently stalking ducks. It did nothing while I watched, but it led to a conversation with a reserve warden who told me of an incident he had observed previously. A heron (no reason to think it was the same one I saw) had been fishing with several ducks around it, when for no obvious reason it struck at a nearby pochard impaling it on its beak. The pochard was killed, but not eaten. He thought it remarkable since he had never seen that happen before.

    Interestingly the warden also told me of instances he had seen of shelducks taking eggs from nests of other ducks. He assumed they ate them, but only actually saw them (on more than one occasion) take them in their beaks and fly off with them.

    Regarding the fossil herons – it seems to me that since fossil bird remains are often so fragmentary assigning them to modern genera often seems to be best viewed as rather tentative.

    Darren refers to Steadman’s Extinction and Biogeography of Tropical Pacific Birds – it is a very impressive book. I didn’t really know what to expect when I ordered it, but it is very good (though somewhat repetitive in parts).

    Terms like species and genus have different ‘definitions’ according to context and user. I guess David was pointing out that genus is quite loosely defined, and often just reflects the opinions of the most recent taxonomist to review a group. That doesn’t mean it’s not a valuable concept, and I think that useful definitions (or at least concepts) have been proposed. I do think we shouldn’t get too hung up about genera being paraphyletic (or even in some cases polyphyletic) – genera like Haplochromis and Cichlosoma in the fish family cichlidae illustrate this as far as I am concerned. This is a very big topic, and being a vervent hater of Phylocode and phylogenetic taxonomy I suspect my views will differ from that of many other readers of this blog. :)

    Darren – sorry to hear you have had a tough week. I hope things work out ok for you.

  19. #19 Darren Naish
    September 2, 2008

    Yup, still around and checking comments, thanks again to all. Herons are clearly frickin’ awesome… and, yes, they do indeed catch and eat doves and ducks (though usually ducklings [images].. incidentally, has everyone seen the photo where a captive shoebill picks up a whistling duck? It doesn’t kill it or eat it however). More on this sort of thing when I get back.

    Shelducks picking up eggs: Mark, these were probably cases of parasitism (or cuckoldry). This is pretty common in ducks, and way more common in birds than most people realise… both interspecific and intraspecific. I used to find starling eggs in the back garden as a kid: my hypothesis (I was 10 yrs old) was that rats had left them there, but now I think they’d been dumped by parasitic females. We now know that some female starlings are habitual cuckoos and lay one of their own eggs in a host female’s nest, at the same time removing one of the host’s eggs (they have to remove an egg because birds can count).

  20. #20 David Marjanovi?
    September 2, 2008

    I guess David was pointing out that genus is quite loosely defined

    No, it’s not defined at all.

    Every few years someone proposes a definition in analogy to the two Biological Species Concepts: if two organisms can produce viable hybrids, they’re in the same genus. This has never been adopted by anyone except maybe (!) temporarily (!) its proponents, because it suffers from the same problems as the Biological Species Concepts, only worse, because data are even more difficult to get.

    That doesn’t mean it’s not a valuable concept,

    It does. Like all ranks above it, it’s an outright damaging concept: it makes people believe that they can count genera in order to quantify biodiversity, when in fact they need to use things like the Phylogenetic Diversity Index (D. P. Faith, 1992 onwards).

    and I think that useful definitions (or at least concepts) have been proposed.

    Like what?

    phylogenetic taxonomy

    There is no such thing. You probably mean phylogenetic nomenclature.

  21. #21 Steve Bodio
    September 2, 2008

    The film I saw (of a heron fishing with bread) was the gren heron, Butorides virescens.

    David– I am fascinated by your “new definition” of genus, partly because a lot of birds are going to need revision if it is so. I know of, in birds of prey, a recent hybrid of Aquila chrysaetos and the ornate hawk- eagle (Spizaetus ornatus). Earlier examples are Buteo regalis X Parabuteo unicinctus and, weirdest of all, P unicinctus X Accipter cooperi.

    Since I suspect that large Buteos could be crossed with eagles that would put all the above in one “genus”. Guess I prefer cladistic trees.

    And we haven’t even gotten to some old crosses of Columba livia and one of the New World doves– I think maybe Zenaida macroura.

  22. #22 David Marjanovi?
    September 2, 2008

    Not mine! One of the proponents is Alain Dubois, the frog researcher at the National Museum of Natural History here in Paris. There are maybe two or three others, and that was it. In my not so humble opinion, applying this definition would be very time- and money-consuming, would change awful lots of names (intergeneric hybrids are not only known in birds — I’m sure Darren can rattle off a long list; some of them are hybrids between current subfamilies), and still wouldn’t make the resulting genera biologically comparable, so it would be futile anyway. And then, of course, this definition is only applicable to extant sexually reproducing organisms in the first place.

  23. #23 Simon Fraser
    September 2, 2008

    The most remarkable bit of bird feeding I’ve ever seen was near a watering hole on the Serengeti. Some kind of flying insect was emerging from the ground and taking flight ( a Termite? ), numerous Swallows were swooping and circling above the ground stuffing their beaks with bugs. While all this was happening there were 3 Marabou Storks (Leptoptilos crumeniferus) seemingly just standing there. Suddenly one of the Storks jabbed it’s head forward, caught a Swallow in it’s beak and swallowed it. As we watched they did this several more times, never missing as far as we could see.
    This is one of the reasons I found your Azhdarchid paper so compelling.
    Great Blog by the way.

  24. #24 Mark Lees
    September 3, 2008

    David, sorry if I misrepresented your views, not my intention. Though it seems we disagree more fundamentally than I thought we did.

    Though I am unable to find it at the moment – I recall reading an interesting proposed definition of genus that wasn’t based on extrapolations of reproduction based species definitions. It was based around the idea of a set composed of species that are similar in terms of biology, morphology etc and that occupy a similar ecological niche and share one or more adaptations related to their niche that distinguishes them from other related genera. I?m afraid I may have somewhat garbled the concept in trying to repeat it, but the idea had some elements that interested me, and allowed for at least some degree of paraphyly and even possibly polyphyly.

    Phylogenetic taxonomy as opposed to phylogenetic nomenclature ? I?m sure your right (though I do think your being a bit picky). Though it doesn?t actually make a lot of difference what you call it as far as I am concerned, I still think it?s rubbish. :)

    Linnaean ranks are artificial ? we all know it. They don?t purport to be anything other than a classificatory mechanism. While it is desirable that they to some degree reflect (or at least don?t conflict with) actual relationships ? that isn?t the be-all-and-end-all, indeed a good classificatory mechanism should be capable of being used when discussing different phylogentic hypotheses.

    Phylogenetic ?nomenclature? ;) seems too subject to change at the whim of the person undertaking the analysis. I?m afraid that while I accept that cladistic analysis plays a part in drawing conclusions about origins and relationships, it usually tells me more about the preconceptions of the person undertaking the analysis. Things like choice of out group, choice and weighting of characters etc all seem way more art than science. And if you think that assigning ranks are also art not science, I would agree to some extent, but Linnaean ranks don?t pretend to be anything other than a model. A fundamental problem with phylogenetic nomenclature is that it is only a model, but it is also strongly associated with a specific phylogenetic hypothesis, and therefore (a) very sensitive to changes in hypothesis; and (b) takes on the feeling of being more than a model and in some sense a picture of reality.

    Give me the manifest artificiality of Linnaean ranks ahead of the illusion of reality that is created by phylogenetic nomenclature.

    To twist a well known phrase ‘there are lies, damned lies, and cladistics’ :)

    I guess that was controversial enough, and I strongly suspect that many/most readers of this blog will disagree greatly with me. But please accept that while I respect your views, I think we have to agree to disagree on this matter.

    In passing, on the matter of hybrids, bird hybrids are more common than one may expect. While bird watching I have several times encountered birds that were probably hybrid.
    In captivity male goldfinches and green finches will attempt to pair with just about any female finch ? and I have seen a wild individual that closely resembled pictures of goldfinch x linnet males hybrids, and several examples of green finch x ‘some other finch’.
    Ducks are also commonly give rise to hybrids and several times I have thought I had discovered a rare vagrant only to discover it was a hybrid (tufted ducks and pochards seem like they haven’ quite got the species concept sorted even among themselves!).
    I once also spotted a grebe that I am as sure as I can be was a Little Grebe x Black-necked Grebe. I spent half an hour watching it carefully, examining it point for point against several field guides and came to the conclusion that it was an almost perfect intermediate (maybe just tending slightly towards black-necked). Other birders also noted it ? some concluding it was an aberrant black-necked grebe, and a few that it was an odd little grebe. I find this one intriguing as it doesn?t occur in ‘Handbook of Avian Hybrids of the World’.

    If you are interested in bird hybrids I recommend ‘Handbook of Avian Hybrids of the World’, by Eugene McCarthy. A large annotated list rather than a discussion, but I find it useful, and considering the sheer volume of information and research involved in it relatively cheap.

  25. #25 Jerzy
    September 3, 2008

    Genus definition based on viable hybrids wouldn’t stand, because intergeneric hybrids in birds are very common. All Anatidae would be one genus, and Phasianidae + Tetraonid/nae.

    I looked at recent book on bird hybrids among the world, and it had some big surprises for molecular biologists. One is several hybrids between cracids genera and chicken – modern view its not just between families, but between orders.

    There is even a mention of Australian bird breeder trying to captive breed lyrebirds. He reported failure… but got accidentally lyrebird x chicken cross – Passeriformes x Galliformes! But I feel thats too incredible to believe without specimen.

  26. #26 Jerzy
    September 3, 2008

    About some extinct island herons – I’m a bit sceptical.

    I feel many recently described “extinct island bird species” are just temporary populations or vagrants of known birds. Bird osteology is difficult and there is a tendency to assume that any bird bone on remote island must be breeding population, at the level of species, and wiped out by man. Yep, you had overkills by ancient man, but you also have island colonization/extinction and vagrancy.

    Kenyon’s Shag from Pacific, first described as new species from subfossil bones, then traced to small females of living shag species.

  27. #27 David Marjanovi?
    September 3, 2008

    But please accept that while I respect your views, I think we have to agree to disagree on this matter.

    What? You want the stop the discussion? What kind of scientist are you? :-) I’ll come back in a few hours, and then I’ll reply to each of your points at length. It is evident that you have misunderstood a lot of things — you don’t even seem to have noticed that cladistics (how to reconstruct a tree) and phylogenetic nomenclature (how to name branches on a tree) are completely independent!

    In the meantime, please read
    - the Wikipedia article linked to above;
    - this paper (pdf) which, among other things, demonstrates that rank-based nomenclature leads to much more instability than phylogenetic nomenclature;
    - the PhyloCode itself (much easier to read than the ICZN, and much shorter).

    One is several hybrids between cracids genera and chicken – modern view its not just between families, but between orders.

    I think I’ve seen the word “Craciformes” once, but apparently it was given up after a very short time when it turned out to describe a paraphyletic group. However, chickens and cracids are pretty far apart; didn’t they diverge in the Eocene?

  28. #28 Jerzy
    September 3, 2008

    Not sure when, but far apart.

  29. #29 Mark Lees
    September 3, 2008

    Thanks for that David. I wasn’t trying to stifle discussion, merely suggesting that this is an area where different outlooks may actually be responsible for our differing conclusions rather than simply evidence. I’m not going to be dogmatic in saying that either is right or wrong, but we certainly view things differently.

    You could be right, perhaps I am misunderstanding. But I think I do understand, I just come to a different conclusion. I do realise that cladistics and phylogenetic nomenclature are different things. But I was (perhaps not very clearly) trying to make a somewhat different point, but I won’t belabour that.

    As for what sort of scientist I am – well I think you were joking, so I’ll leave that one – lol.

    Any way on to more interesting stuff.

    Sibley & Ahlquist united Cracidae and Megapodidae in an order Craciformes as sister group to Galliformes. Most more recent authorities have placed Cracidae and Megapodidae in Galliformes (dispensing with Craciformes) and treated the Megapodidae as sister group to the rest of the Galliformes.

    I checked Handbook of the Avian Hybrids of the World and The Pheasants of the World – Biology and Natural History for Phasianidae x Cracidae hybrids – I found the following :

    Gallus gallus x Ortalis guttata – early 20th century anecdotal evidence – said to cross easily, but now seems to be considered a mistaken identification.

    Gallus gallus x Ortalis vetula – 19th century anecdotal evidence

    Gallus gallus x Penelope superciliaris – reported captive hybrid from Brazil

    Gallus gallus x Penelope sp – a museum specimen is said to exist, but apparently cannot be traced, and it seems unclear if this was a complete specimen or just a sternum. Another references to Gallus gallus x Penelope sp states that specimens were obtained in Paraguay and kept at Buenos Aires zoo, but it seems unclear what evidence other than anecdotal there was that this was a hybrid, and the snippet of an account in McCarthy suggests that the original author Holmberg thought it was just an unfamiliar species of guan (Penelope sp).

    Gallus gallus x Crax alberti – apparently several accounts of this all seem to trace back to a single 19th century anecdotal account, which is considered dubious.

    Gallus gallus x Crax blumenbachii – reported captive hybrid, the description does seem intermediate.

    Gallus gallus x Crax sp – report of a captive hybrid between a male curassow and a female chicken. Said to be poorly documented and dubious.

    Gallus gallus x Pipile jacutinga – reported captive hybrid, the description, though not detailed, seems to be intermediate.

    Numidia meleagris x Penelope superciliaris – reported captive hybrid

    None of these reports can be considered confirmed. The Gallus gallus x Crax blumenbachii seems to have the most going for it.

    The alleged hybrids between domestic chickens and lyre birds were shown at bird shows in Melbourne. They were capable of producing fertile young when mated with each other. Based on the very brief description I am fairly sure this was just an odd breed of domestic chicken.

    Reported hybrids between domestic chickens and tinamous were shown to be just a breed of chicken.

    There have been several reports of domestic chicken x mallard duck hybrids – all very doubtful. There was also a reported guineafowl x mallard – also very very dubious.

    A 1930s report of a budgerigar x canary from California is based on a bird that is said to have looked like a green canary, but with a heavily curved upper mandible and a longer than usual tail. Besides its slightly odd appearance there seems to have been no other evidence supporting its unlikely hybrid origin.

    I hope that helps.

  30. #30 Oruga
    September 4, 2008

    I always knew heron was a queen of birds, so I’m not too surprised it can eat rabbits. What I’m pondering about is how it can swallow such big prey with it’s S-shaped neck. So I’ll wait for the post about anatomy.

  31. #31 David Marjanovi?
    September 4, 2008

    Sorry for the delay.

    Phylogenetic taxonomy as opposed to phylogenetic nomenclature ? I?m sure your right (though I do think your being a bit picky). Though it doesn?t actually make a lot of difference what you call it as far as I am concerned, I still think it?s rubbish. :)

    Taxonomy is how to make a classification. Nomenclature is how to name taxa. These don’t need to have any connection at all.

    Linnaean ranks are artificial ? we all know it. They don?t purport to be anything other than a classificatory mechanism.

    And then the same people who state explicitly that the ranks are artificial and have no meaning turn around, in one case (Benton’s latest paper in Acta Palaeontologica Polonica) within the same sentence in the abstract, and say they are in fact great proxies for quantifying biodiversity. And then they go ahead, count genera, families or even orders, and present the results as if they had quantified biodiversity, when in fact they have quantified the shifting opinions of a couple taxonomists as to which clade (or paraphyletic assemblage…) should be awarded which rank.

    The ranks are positively misleading. There are papers on this (the one I linked to cites one or two of them).

    While it is desirable that they to some degree reflect (or at least don?t conflict with) actual relationships ? that isn?t the be-all-and-end-all, indeed a good classificatory mechanism should be capable of being used when discussing different phylogentic hypotheses.

    What do you mean? That paraphyletic taxa make sense for ecologists, for example? Then let them have them. Just don’t let them impose those taxa on everyone else. (Or each other. Not all ecologists, functional morphologists, etc. can make use of a compatible set of paraphyletic taxa.) Some people need Reptilia, other people need Archosauria, and both cannot exist in the same classification. Some need Mammalia, others need to talk about the currently unnamed group of egg-laying synapsids, again a conflict.

    The PhyloCode (not phylogenetic nomenclature in general) cuts this Gordian knot by only allowing clades to be named. Clades objectively exist, and they make at least some sense for everyone (“nothing in biology makes sense except in the light of evolution”, “nothing in evolution makes sense without a good phylogeny”). We need to talk about the tree. Rank-based nomenclature prevents us from naming certain clades because they overlap with named paraphyletic taxa. Away with the problem!

    Phylogenetic ?nomenclature? ;)

    Well, how is it not nomenclature?

    seems too subject to change at the whim of the person undertaking the analysis.

    Man, have you got it backwards. Phylogenetic nomenclature has one source of instability: disagreements about the phylogeny, i. e., contradicting scientific hypotheses. Rank-based nomenclature has three sources of instability: disagreements about the phylogeny, mood swings about which taxa should be given which ranks causing name changes up and down the classification, and mood swings about which paraphyletic taxa should be officially recognized. Fine, the last of these three is slowly dying out, but that still leaves two. See the paper I linked to for what this means in numbers.

    I?m afraid that while I accept that cladistic analysis plays a part in drawing conclusions about origins and relationships, it usually tells me more about the preconceptions of the person undertaking the analysis. Things like choice of out group, choice and weighting of characters etc all seem way more art than science.

    You have changed the topic. You have changed the topic from nomenclature (the conventions on how to name branches on a tree) to phylogenetics (the science of how to reconstruct the tree). It is very important to be aware of this difference. Phylogenetic nomenclature does not require cladistics. If you’re familiar with bird origins, you’ll know that Gregory S. Paul uses phylogenetic nomenclature in his 2002 book Dinosaurs of the Air, but rejects cladistics.

    Perhaps you prefer it in philosophical terms: Phylogenetic nomenclature names objective reality, the really existing tree. It is applied to phylogenetic hypotheses, hypotheses about what objective reality looks like. These hypotheses may have been generated and tested by means of cladistics — or not.

    (But I like digressions. :-) Choice of outgroup: Don’t choose, use all that are reasonably close. The more, the merrier, because adding taxa breaks up long branches and improves the chances that the reconstruction of the ancestral states for the ingroup are correct. Choice of characters: Great care must be taken to eliminate correlated characters, and eliminating characters that lack phylogenetic signal doesn’t hurt either. Although they are almost never used, two different tests exist, one for both problems and one for phylogenetic signal only. I’ll supply references later. But the most important thing is to have a high enough ratio of characters to taxa. There is a theoretical limit above which adding characters adds asymptotically less signal, but this seems never to have been reached; if you can’t find at least three times as many characters as taxa, don’t bother publishing. Numbers help because the signal will add up while the noise, being random, will cancel itself out. Weighting of characters: In morphology, a priori weighting is currently impossible, so everyone gives all characters the same weight. A posteriori weighting is interesting, is implemented in PAUP* and a few other programs, and is occasionally used.)

    And if you think that assigning ranks are also art not science, I would agree to some extent, but Linnaean ranks don?t pretend to be anything other than a model.

    But they aren’t even a model. There’s no hypothesis attached to them. They are a meaningless, and (see above) actively misleading, convention.

    Nonetheless, phylogenetic nomenclature in general, and even the PhyloCode in particular, does not forbid the use of ranks. It only removes their influence on names.

    A fundamental problem with phylogenetic nomenclature is that it is only a model,

    No, it is not a model either. It is nomenclature. It names things, it doesn’t predict anything about them.

    but it is also strongly associated with a specific phylogenetic hypothesis,

    The precise contents of the taxon to which a name applies do depend on the phylogenetic hypothesis to which the name is applied. But — see above — they don’t depend on anything else. Splitting and lumping are impossible under phylogenetic nomenclature. Yes, seriously.

    Give me the manifest artificiality of Linnaean ranks ahead of the illusion of reality that is created by phylogenetic nomenclature.

    Please explain.

    To twist a well known phrase ‘there are lies, damned lies, and cladistics’ :)

    That’s the third time you change the topic.

  32. #32 Carpworld
    September 4, 2008

    Sorry for the lateness and apologies for an old link but the pelican eating a pigeon video seems appropriate here:

    http://www.youtube.com/watch?v=PO5ifLzLYiU

    I always thought azhdarchids looked like these things.

  33. #33 Zach Miller
    September 4, 2008

    I’ve really got to take a closer look at PhyloCode. I just never have the time. I certainly agree that the Linnaean structure leads to more headaches than reliefs. Just recently on my blog I described my irritation about how mammalian and dinosaurian taxonomy differed, and then how extent and extinct taxonomy–even among members of the same family–differ.

    My “from the gut” paleoartist definition has always been this: If the skeleton suggests features which would differentiate an animal from its relatives after you apply all of the muscles and skin, it’s a different genus. Otherwise, it’s simply a different species. Unless, that is, you can make a good case for sexual dimorphism, which I always encourage.

    Example: Velociraptor mongolensis and Velociraptor osmolskae would be different species (not genera) because the features which separate them (differences in the maxilla), while fairly significant, would not be noticable on the living animal. Of course, what if we find the entire skeleton of V. osmolskae and discover that it looks completely different? I’ve never cared for the practice of naming a new animal based on such scrappy remains as a single maxilla!
    Anyway, Velociraptor is a separate genus from Deinonychus because of size, location, and age differences. The two would look very different with all the meat on their bones.

    That’s just my artistic interpretation, but I’ll admit that even this simplified definition has problems…:-(

    Could somebody explain how PhyloCode addresses the arbitrarity (not a word) of the Linnaean system?

  34. #34 Nathan Myers
    September 4, 2008

    arbitrarity (not a word)

    It is now.

  35. #35 William Miller
    September 4, 2008

    I’m sorry, but one question: in a system such as PhyloCode which allows only clades to have names, how does one refer to groups such as “Reptilia”?

    Doesn’t “Reptilia” paraphyletically defined as excluding birds, still have ecological/functional validity, even though not evolutionary? Birds have a very different set of niches than reptiles-minus-birds.

  36. #36 David Marjanovi?
    September 4, 2008

    Could somebody explain how PhyloCode addresses the arbitrarity (not a word) of the Linnaean system?

    By leaving it.

    And if you think you don’t have time to read it, think again. It’s short. It has just 22 articles.

    Doesn’t “Reptilia” paraphyletically defined as excluding birds, still have ecological/functional validity, even though not evolutionary?

    IMHO, less and less the longer you look at it. The Center for North American Herpetology, for example, has recently restricted the meaning of “reptile” to “lepidosaur”, so they now send out newsletters referring to the “reptiles and turtles of North America”, for example.

    But if you still want to use it, go ahead. You can even give it a phylogenetic definition. All you’re forbidden to do is to give it an official, registered name.

    And if you had read the Wikipedia article I linked to, you would know all that :-)

  37. #37 Zach Miller
    September 4, 2008

    I use the term “Reptilia” to refer to all tetrapods that are NOT synapsids. I’ll print out the PhyloCode and read it over a few days. I’m a slow reader! :-)

  38. #38 kad
    September 4, 2008

    Interesting comments/discussions, but one cannot help but notice that everyone is dancing around the REAL issue here, namely…

    are herons capable of climbing up their rabbit prey?

  39. #39 William Miller
    September 4, 2008

    only if they (the rabbits) are struck by meteoroids!

  40. #40 Nathan Myers
    September 5, 2008

    And can herons and rabbits engage in cuppa?

  41. #41 johannes
    September 5, 2008

    > I use the term “Reptilia” to refer to all tetrapods that
    > are NOT synapsids.

    Including non-amniote tetrapods, like lepospondyls, temnospondyls and lissamphibians :-0?

  42. #42 Horwood Beer-Master
    September 5, 2008

    Speaking of furry creatures being attacked by dinosaurs, Darren, could you or one of your readers help in identifying Professor Steve Steve’s attacker before it strikes again? I’m sure the little panda would be very grateful.

  43. #43 David Marjanovi?
    September 5, 2008

    BTW, Zach, your blog only allows comments from people with a Google/Blogger account, so I have to say it here: in your “deadline” post you have a logo that shows the crown-group definition of Archosauria (MRCA of birds and crocs, and all its descendants) above the skull of Euparkeria — which, under this definition, is not an archosaur.

  44. #44 Mark Lees
    September 5, 2008

    David, thank you for the effort you have gone to, but I remain unmoved. I apologise if my comments indicated I didn’t understand, or that I was changing the subject. I don’t think either was actually the case, though I may well have been unclear in my statements. If you check the literature you will see that I am not alone in using Phylogenetic nomenclature and phylogenetic taxonomy as closely related terms, though not it is true actually synonyms. Also the connection with cladistics is not one that I am unique in making.

    I had previously read Phylocode (it is at least refreshingly short) – I wasn’t impressed then, and on rereading it at your suggestion I remain unimpressed. I have now also read the Wikipedia item – sorry it hasn’t changed my views.

    You state that: “The precise contents of the taxon to which a name applies do depend on the phylogenetic hypothesis to which the name is applied” – absolutely, which is why, for example, Benton states that “the name Deinonychosauria,which can contain 20 or 10,000 species depending on which current tree is correct.” All I can say is that is an interesting concept of stability, and that such a system may be stable, but it also crap.

    Some potentially very useful literature has to my mind been ruined by pointless and seemingly endless PN defnitions. Monsch, 2006 and Benton, 2007 both available free from Acta Palaeontologica Polonica – give in my opinion a good summary of why Phylocode is best aborted now before it does any further damage.

    By the way ‘there are lies, damned lies, and cladistics’ was a joke.

    Anyway – I think we are hogging this thread with an off topic matter, so perhaps best we get back to herons devouring innocent lagomorphs!

    NB Rabbits are notorious for engaging in cuppa!

  45. #45 Sven DiMilo
    September 5, 2008

    I predict the term “genus” will largely fall out of use over the next decades.

    Are we to abandon binomial species names? If not, haw will we refer to the noun in the binomial if not as a “genus”? And if so, who’s going to come up with all those new nonredundant species names?

  46. #46 Sven DiMilo
    September 5, 2008

    Guess I should add that, in case it’s not obvious, I know jackshit about the PhyloCode, mainly because I don’t care much what you want to call the organisms that interest me. Just keep it so I can use a term for a species that means the same thing to everybody. Thanks.
    (So I’m too lazy to read the damn thing–are we supposed to abandon binomials?)

  47. #47 Zach Miller
    September 5, 2008

    David, yeah, I know. I’m not doing Euparkeria; Scott Elyard is. We’re both aware that little bugger is an Archosauriform (not an archosaur proper), but Scott wanted to start at the beginning and restore the birth of a dynasty, as he puts it. Don’t worry–Scott’s write-up for Euparkeria will make everything clear.

    And I didn’t mean tetrapods–brain fart there. Amniotes! Reptilia = all non-synapsid amniotes!

  48. #48 ScottE
    September 5, 2008

    “Scott wanted to start at the beginning and restore the birth of a dynasty, as he puts it.”

    Man, did I actually put it that way? That’s pretty good. I should write that down.

  49. #49 Tommy Tyrberg
    September 6, 2008

    Tommy Tyrberg here.

    Sorry for the late response. I’ve been down in Australia for the SAPE (Society of Avian Paleontology and Evolution) meeting and then out in the outback birding. I only just got around to catching up with Tetrapod Zoology.

    As for the Easter Island Heron I have nothing to add, nothing is known about it in addition to the original find.

    However there are several extinct island Nycticorax known from the Pacific. Nycticorax kalavikai from Niue, and unnamed forms from Buka, Tonga and Mangaia.
    As for the validity of such island forms, that is of course a difficult question. They were almost certainly reproductively isolated, but may well have been able to interbreed with other populations if they had an opportunity. In some cases there are however rather striking morphological changes such as in Nycticorax carcinocatactes on Bermuda which was adapted to feeding on (very hard) land crabs. Incidentally the crabs became a pest after the herons were exterminated, so Night Herons have been (re)introduced to Bermuda to control them. This has been completely succesful, but while waiting for evolution to take its course the poor herons have to keep bashing each crab for an average of 15-30 minutes to get at the crabmeat.

  50. #50 kereng
    September 6, 2008

    As for the Easter Island Heron I have nothing to add

    May I add that it feeds on Easter Bunnies!?

  51. #51 Nathan Myers
    September 6, 2008

    With kereng‘s posting, this thread is officially over. Nothing could possibly top that.

  52. #52 David Marjanovi?
    September 7, 2008

    Are we to abandon binomial species names? If not, haw will we refer to the noun in the binomial if not as a “genus”? And if so, who’s going to come up with all those new nonredundant species names?

    Very good questions, and it took very long to solve them. However, they are now solved. Basically, governing species names is left to the rank-based codes, and then the genus name is interpreted away. This is now (and has been for close to two years) Article 21 of the PhyloCode; read it for yourself. If that’s not enough as an explanation, try this paper:

    Benoît Dayrat, Philip D. Cantino, Julia A. Clarke & Kevin de Queiroz: Species names in the PhyloCode: the approach adopted by the International Society for Phylogenetic Nomenclature, Systematic Biology 57(3), 507 — 514 (June 2008)

    ———————————

    You state that: “The precise contents of the taxon to which a name applies do depend on the phylogenetic hypothesis to which the name is applied” – absolutely, which is why, for example, Benton states that “the name Deinonychosauria,which can contain 20 or 10,000 species depending on which current tree is correct.” All I can say is that is an interesting concept of stability, and that such a system may be stable, but it also crap.

    Well, this is one more piece of evidence that Benton didn’t read the PhyloCode. (Hey, we’re talking about the man who publishes faster than his shadow!) There are plenty of Rules and Recommendations in the PhyloCode against such careless definitions that have totally different contents depending on the phylogenetic hypothesis, and have been for years.

    Perhaps the most important one is Article 4.2, which requires peer-review for valid publication! That’s right: every name and every definition must pass peer-review.

    Then it goes on with Recommendations 9A and 9B, Recs. 11.7A and 11.7B, Art. 11.8 and Recs. 11A through 11G.

    And if all that fails, you can simply emend the definition! Arts. 15.8 through 15.15 have been part of the PhyloCode for as long as the Article on species names (see above). Read especially Art. 15.11 with its notes and their examples.

    Finally, keep in mind that nothing prevents me from declaring Deinonychosauria a superclass and including Class Aves in it under the ICZN. Under the ICZN, Deinonychosauria does not even have a type! (Only superfamilies and lower-ranked taxa have types.) Consider Cotylosauria for a moment: it was created for Diadectes, which was thrown out of Cotylosauria once Cotylosauria became understood as a wastebasket for basal amniotes and Diadectes turned out not to be an amniote. That’s completely legal, and if you read a 19th-century paper that mentions Cotylosauria, you have to know all this history to understand what it talks about. Or consider Plantae: ever since it has been used as a clade name, it has been used for at least three different nested clades (all eukaryotes with a plastid by primary endosymbiosis; all members of the previous clade whose plastids are green, i. e., contains chlorophyll b, and who are multicellular homologously to land plants; land plants only). All this is allowed and in fact inevitable under the rank-based codes, and forbidden under the PhyloCode. Single source of instability, remember? No splitting, no lumping.

    ————————————-

    I apologise if my comments indicated I didn’t understand, or that I was changing the subject. I don’t think either was actually the case, though I may well have been unclear in my statements.

    I maintain that you changed the subject — back and forth between phylogenetic nomenclature and cladistics — without noticing it. This is only possible if you didn’t understand this difference — as is also suggested by your next sentence:

    If you check the literature you will see that I am not alone in using Phylogenetic nomenclature and phylogenetic taxonomy as closely related terms, though not it is true actually synonyms.

    You are in the best possible company — the seminal theoretical papers on phylogenetic nomenclature have “phylogenetic taxonomy” in the title (e. g. de Queiroz & Gauthier 1992). These authors have been made aware of the difference between taxonomy and nomenclature and have all been using the term “phylogenetic nomenclature” for the last several years. Perhaps most importantly, the PhyloCode has always used it ever since the first draft came online in 2000. So, let me just repeat: taxonomy is how to make a classification, nomenclature is how to name taxa. Interestingly, the rank-based codes conflate these to some extent (for example, to name a species you must at least pretend to know something about its phylogenetic relationships, because you have to put it into a genus), while the PhyloCode keeps them apart; I’d even go so far as to say that phylogenetic nomenclature makes taxonomy superfluous. Instead, make a tree (that’s called the science of phylogenetics) and then tie labels to its branches (phylogenetic nomenclature); you can, but don’t need to “translate the tree into a classification” — you can just include the labeled tree in your publication as a figure. There is a book on extant vertebrate anatomy whose table of contents is a labeled tree.

    Also the connection with cladistics is not one that I am unique in making.

    That still doesn’t make it correct.

    The only connection there is is historical — cladistics made it much easier to get testable phylogenies, so tree-thinking started, and the romerograms began to disappear; Hennig wanted to name only clades; phylogenetic nomenclature is designed for making this easy (even though it can just as easily be used to define the names of paraphyletic and even polyphyletic taxa — but the PhyloCode forbids that). Cladistics and phylogenetic nomenclature were introduced into several fields by the same seminal paper, like Gauthier (1986) for theropod phylogeny and bird origins; this has led many people to believe they are two parts of the same thing, but that’s not the case. You can have cladistics and the principle to only name clades without phylogenetic nomenclature (anything by Hennig; Patterson & Rosen 1977; anything by Benton after the mid-80s, except he does use a few paraphyletic taxa; Frost et al. 2006, who don’t even use ranks above the superfamily; and so on); and you can have phylogenetic nomenclature without cladistics (Paul 2002).

    Monsch, 2006 and Benton, 2007 both available free from Acta Palaeontologica Polonica – give in my opinion a good summary of why Phylocode is best aborted now before it does any further damage.

    Yeah. Monsch evidently didn’t understand what he was talking about, though, to be fair, the articles on species names and emendations didn’t yet exist when he wrote his paper; Benton (2007) is the paper I mentioned that manages to contradict itself — even in the same sentence, and that sentence is even in the abstract — on whether ranks mean something or not, and contains odd ideas about how stable, say, the classification of Carnivora has been lately. If you want, I can give details on both, though I recommend you read a couple of recent papers first, most importantly Laurin (2008) which is linked to above. “Damage”? The rank-based codes are best restricted to species before they do any further damage! :-)

    Anyway – I think we are hogging this thread with an off[-]topic matter

    You think? I think Darren needs more traffic :-)

  53. #53 David Marjanovi?
    September 7, 2008

    (I have written a long comment on phylogenetic nomenclature with too many links in it, so it’s awaiting moderation. Check back when Darren comes back.)

  54. #54 Andreas Johansson
    September 8, 2008

    Finally, keep in mind that nothing prevents me from declaring Deinonychosauria a superclass and including Class Aves in it under the ICZN.

    And just to drive the point about sources of instability home again, there’s nothing in the ICZN stopping me from putting Subinfracohort Aves in Superduperdivision Deinonychosauria. Phylogenetic nomenclature is unstable when the phylogeny is poorly known, rank-based nomenclature is unstable whether the phylogeny is known or not.

  55. #55 Edgar
    September 8, 2008

    And returning to the heron; anyone knows what happened with this bird? not become a scourge for rabbits farms?or now exist a entire colony of rabitt eating herons?

  56. #56 David Marjanovi?
    September 8, 2008

    And just to drive the point about sources of instability home again, there’s nothing in the ICZN stopping me from putting Subinfracohort Aves in Superduperdivision Deinonychosauria.

    Or all turtles back into Testudo the way Linnaeus had it. Or all crocodiles back into Lacerta crocodilus. Or all caudates except Siren into Lacerta salamandra. I kid you not.

  57. #57 Zach Miller
    September 8, 2008

    Deinonychosauria doesn’t have a TYPE? Well, I suppose that’s…understandable. You can’t use Troodon or Deinonychus because Deinonychosauria includes both families (Troodontidae & Dromaeosauridae). You can’t use Mahakala because it lacks a few features present in both dromaeosaurs and troodontids (short arms, for one thing). Rather, Mahakala might better represent a basal paravian, but things get even muddier there, don’t they?

    Can Mahakala stand to be the type for a group that includes, on one hand, Utahraptor, and on the other hand, storks? I suppose it can, if we can show that Mahakala represents some arbitrarily small number of specialized features unique to both the ancestor of deinonychosaurs and birds.

    And then you’ve got ambiguously basal taxa like Archaeopteryx, who could either be a basal paravian, deinonychosaurian, or bird. Does Mahakala or the urvogal better represent the SPLIT between deinonychosaurs and birds? And is that even something we’ll ever know?

    Man, my head hurts.

    So, I guess my question is this: Is it even possible to determine a type species for any clade larger than the rank of Family?

  58. #58 William Miller
    September 8, 2008

    “Perhaps the most important one is Article 4.2, which requires peer-review for valid publication! That’s right: every name and every definition must pass peer-review.”

    Is this really a wise idea? I’d always heard that many biologists wanted to be able to name & classify as many species as possible, so that we would have warning if stuff was going extinct; we wouldn’t know if it was in trouble/extinct if it had never been described. Wouldn’t making the naming process more involved slow this down? Are there even enough peer-reviewers to review every species named?

  59. #59 Nathan Myers
    September 9, 2008

    @William Miller: Good point. There had better be an exception for bugmen, or Chris Taylor will need a lot more than two decades to catalog the daddy-long-legses properly.

  60. #60 David Marjanovi?
    September 9, 2008

    Deinonychosauria doesn’t have a TYPE?

    Nothing above the family group of ranks has a type under the ICZN. Above the family group very few ICZN rules apply — basically those on spelling. Not even priority applies. Zoological names above what amounts in most cases to the superfamily rank are practically a code-free zone.

    Wouldn’t making the naming process more involved slow this down? Are there even enough peer-reviewers to review every species named?

    Read Article 21 again: the PhyloCode will not regulate species names.

    Besides, I bet even most species names are nowadays being published in peer-reviewed journals anyway.

  61. #61 David Marjanovi?
    September 9, 2008

    Incidentally, you can read the entire ICZN here.

  62. #62 Jerzy
    September 9, 2008

    Well, if you have traditional taxonomy, you cite family, order, class and phyllum to give taxonomical information. For cladistic taxonomy, you should give 1000′s of clade names from the first split of Eubacteria and Archaea+Eukaryota.

    In practice, cladistic just omits the problem and picks some clade names as you please and free for all. It is not “more stable” or “more informative”, just no rules.

    You could e.g. describe taxonomical position of Deinonychus as (Eukaryota, Bilateria, Celomata, Amniota). Or pick any other obscure and uninformative clades. Or describe cladistic position of one taxon 10 times, never using the same clade names twice, creating chaos.

  63. #63 Andreas Johansson
    September 9, 2008

    You could e.g. describe taxonomical position of Deinonychus as (Eukaryota, Bilateria, Celomata, Amniota). Or pick any other obscure and uninformative clades.

    I can do the same while conforming to the traditional phylum, class, order, family scheme merely by arbitrarily reranking the groups in question. No nomenclatural code is proof against deliberate obfuscation.

    Further, your implication that under PN one should name every clade an organism belongs to is a strawman – nobody is saying any such thing.

  64. #64 David Marjanovi?
    September 9, 2008

    Well, if you have traditional taxonomy, you cite family, order, class and phyllum to give taxonomical information.

    That’s not even true, neither in theory (the codes say nothing about it) nor in practice.

    And once again, there is no such thing as “cladistic taxonomy”, and phylogenetic nomenclature has nothing to do with cladistics!

    BTW, do try to distinguish phylon “stem” from phyllon “leaf”… :-)

  65. #65 Tobias
    September 9, 2008

    As a non-scientist all I can do is ask: does this mean that Kings no longer Play Chess on Funny Glass Stools?

    Damn, I think that’s the only thing I remember from high school biology.

  66. #66 Jerzy
    September 9, 2008

    Forgive my disinterest in naming. What I say, that in both approaches you must pick few taxonomic divisions which best describe species status. In traditional taxonomy its formalized. Using clade names you will soon have the same problem. Basically, important is clarity, and problem of naming or taxonomy is secondary.

  67. #67 Christopher Taylor
    September 9, 2008

    Forgive my disinterest in naming. What I say, that in both approaches you must pick few taxonomic divisions which best describe species status. In traditional taxonomy its formalized.

    But as pointed out by Andreas and David, that appearance of formality is actually an illusion, because there is no guarantee as to which taxa are at which rank. Even worse, two completely different taxa put at the same rank by two different classification systems may be required to have the same name (compare different interpretations of “Hominidae”, for example), which can compromise the informativeness of the ‘formally significant’ taxa.

    In practice, besides, researchers use whichever taxa are most informative in the context of what they’re working on. I work alongside a number of ant researchers – all ants belong to the family Formicidae, but the universal nature of that taxon for their purposes makes it pretty useless, so they always refer to the separate subfamilies.

  68. #68 David Marjanovi?
    September 10, 2008

    I have seen things like “Dinosauria: Theropoda” much more often than “Reptilia: Saurischia”.

    all ants belong to the family Formicidae

    Wow. Just… wow.

  69. #69 Darby
    September 10, 2008

    Since I teach basic taxonomy to basic students (you know what I mean), I would like to be able to at least give a flavor of Phylocode, since that may be what many of them will be using. And I have tried, several times, to wade through the website and develop an understanding myself of how the system is constructed and used.

    It always gives me a headache. I have no clue how the taxonomy or the nomenclature is used beyond any given clade and a few neighboring ones. I can’t see any cohesive system in it, and it’s hard to imagine how it would be useful to someone learning, for instance, basic entomology.

    I come away with the vague impression that I’ve been briefly watching a cult ritual, but lack the indoctrination to know what the heck they were doing or why they were doing it.

    This is just an impression, and I am getting older and slow of mind, but I have to think that my problems with it aren’t mind alone.

  70. #70 Darby
    September 10, 2008

    Not an attempt at clever phrasing, just a typo – mine alone.

  71. #71 David Marjanovi?
    September 10, 2008

    70 comments are not enough! We need to reach Pharyngula level!

    It always gives me a headache. I have no clue how the taxonomy or the nomenclature is used beyond any given clade and a few neighboring ones. I can’t see any cohesive system in it, and it’s hard to imagine how it would be useful to someone learning, for instance, basic entomology.

    If you could be a little more precise about what exactly you don’t understand, I’d be glad to explain.

  72. #72 Angela C
    September 16, 2008

    Wow, that is just amazing. I’ve seen a lot of these birds locally but I’ve never seen one eat a rabbit! Thanks for sharing these photos.

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