I have a lot on at the moment, so getting this finished wasn't easy - but I managed it. Here we are with the rest of my recollections from 'Dinosaurs (and other extinct saurians) - A Historical Perspective', held at Burlington House (home of the Geological Society of London) on May 6th and 7th (part I here). This time round we look at the second day of talks, as well as the posters and whatever else I can think to write about...
So, the day kicked off with Phil Currie's talk on the history of dinosaur hunting in Asia. Yes, Phil Currie. After talking about the AMNH expeditions of the 1920s, Phil discussed the Chinese excavations of the 1930s and 40s, the USSR expeditions of the 1940s (in one year they removed more than a hundred tons of dinosaur bones), the Sino-Soviet expeditions of 1959 and 1960, the Polish expeditions of 1963-1971, and others. A lot of stuff, a lot of dinosaurs! Darren Tanke was up next, with 'Lost en route to England: the 1916 sinking of the SS Mount Temple and her Canadian dinosaur cargo'. Darren has gathered a huge amount of information about the SS Mount Temple, its history, and what happened to it on December 6th 1916. It was a story involving banana shipments, U-boats, examination of old photos, archaeology of Canadian dig sites, and lost dinosaur fossils. Geoff Tresise and Alan Bowden spoke about changing views on Chirotherium trackways, and on the sorts of environments the trackways are preserved in.
Christopher Ries discussed Gerhard Heilmann's (1859-1946) ideas and achievements: an incredibly gifted natural history artist, Heilmann produced outstanding drawings and paintings of living animals, and also designed coins and notes. He struggled with religion and eventually rejected it (he even had a go at reconstructing angels, as you can see from the adjacent photo), and corresponded with several experts as he became increasingly interested in avian origins, developing his ideas in parallel with those of D'Arcy Wentworth Thompson. We were then back to pterosaurs, with David Unwin examining the question 'Are we making progress?'. The answer was a resounding yes, with agreement now reached on most of the major issues once deemed problematical in pterosaur research (cough pteroid orientation cough), and with awesome new discoveries in the Lower Cretaceous of China and elsewhere helping to fill in at least some of the gaps in pterosaur evolutionary history. Octávio Mateus then spoke about the history of dinosaur work in Portugal: one interesting snippet was that Upper Jurassic dinosaur tracks from Cabo Espichel, exposed on a vertical cliff face, were interpreted in the 15th century as having been made by the donkey that carried the Virgin Mary (cue picture of Mary riding on the back of a dinosaur, I kid you not). Vanda Santos and Luís Rodrigues also covered this story on their poster. At the end of Octávio's talk, Peter Wellnhofer expressed his opinion that the cf. Archaeopteryx teeth described from Guimarota by Weigert (1995) cannot really be from Archaeopteryx because they possess serrations.
Peter Wellnhofer summarised the Archaeopteryx story, finishing with a brief discussion of his new book on the subject (he had a copy with him). I learnt in discussion that an English version is planned, and will appear not too far in the future. Cevdet Kosemen (with John Conway) gave a great talk on 'Visualising pterosaurs', although actually it was on 'pterosaurs through the ages' I suppose. With excellent new reconstructions (and not the same old boring ones we all know so well), they discussed Newman's marsupial bats, Wagler's aquatic flippered Pterodactylus, the scaly-skinned reptilian pterosaurs of the early 20th century, and, finally, different modern renditions of pterosaurs. Of course the biggest surprise (for most people in the audience) was Pterodactylus as imagined by Dave Peters: a flamboyant, bipedally walking lizard with ultra-narrow wings, elaborate cranial and dorsal crests, and a long tail [Kosemen and Conway depiction of such shown here]. Few people outside of pterosaur research are familiar with Dave's view of pterosaurs (for a little more on this issue go here), and there was an appropriate amount of gasping and swooning from some quarters of the audience. Kosemen and Conway also displayed a poster that showcased these different models. Attila Ösi discussed three Solnhofen pterosaur specimens stored in Hungarian collections. One is the supposedly lost 'Pester Exemplar' holotype of Pterodactylus micronyx Meyer, 1859. Donated to the Budapest University by Archduchess Maria Anna (1738-1789) in 1781, it therefore predates Collini's 1784 description of P. antiquus.
In the final talk session of the entire meeting, Jean Le Loeuff looked at Mathurin Méheut's artwork (in 1943 Méheut produced a fairly surreal painting titled Les Diplodocus), and Allison Ksiazkiewicz spoke about... about.. well, I'm not entirely sure, but it was something to do with how viewers interpret the gaze of ancient animals as depicted in artwork. And, in the very last talk of the conference, Jeff Liston provided an outstanding overview of how the dinosaur renaissance was depicted in the comics and books of the 1970s. A 1977 story from 2000 A.D., 'Flesh', has Late Cretaceous theropods ganging up on villainous humans who have come back in time to harvest herbivorous dinosaurs. Led by the matriarchal tyrannosaur Old One Eye, a coalition of tyrannosaurs and spinosaurs co-operated: where else could you hear the line 'From the north came the furry tyrannosaurs'? Important is that the story incorporated Deinonychus. So agile, furry dinosaurs had infiltrated popular culture pretty soon after Bakker's early articles (Bakker 1968, 1971, 1972, 1975). Halstead's The Evolution and Ecology of the Dinosaurs (a formative volume for my young self) included a lot of this new stuff (even if Halstead himself strongly disagreed with it), with the excellent paintings of Giovanni Caselli depicting such things as a furry Sordes, an agile Deinonychus, and even a running tyrannosaur (Halstead 1975). At least some sci-fi stories of the 1970s pre-empted 'Jurassic Park' in just about all of the key details.
So that's it for the talks. There were also quite a few posters at the meeting. Dick Moody and I displayed one on the contributions of Alan Charig (1927-1997), John Sibbick and colleagues had one on reconstructing Baryonyx, and there were many others. Niels Bonde's poster, on new anatomical details gleaned from some of the Archaeopteryx specimens, included the startling news that the London Archaeopteryx might possess an alula: it is reported that reviewers and editors have been hostile to this idea and hence have prevented its publication. Niels also contends that the vertebral and pelvic pneumatisation reported previously (Christiansen & Bonde 2000), and later called into question (O'Connor 2006), is indeed genuine.
On the Thursday morning, a select elite set out from London and headed to the Isle of Wight, where brilliant weather (a bit too brilliant I think) provided us with excellent viewing conditions for our coastal excursion. We looked at the iguanodontian tracks at Hanover Point, at exposed plant debris beds, and at some neat land slips, but didn't find any tetrapod fossils. More interesting were the water buffalo, llamas and helmeted guinea-fowl that inhabit the island... I'm not joking! And on the Friday we visited Dinosaur Isle Museum: I had hoped to give a sort of guided tour, but this proved simply impossible because of the constant chorus of loud animal noises made by the museum's overhead system. It's a neat museum for Wealden dinosaurs: the holotypes of Neovenator [shown below] and Eotyrannus are on display, as is the Barnes High brachiosaur, 'Angloposeidon', an awesome Goniopholis specimen, and much else [image above shows the so-called 'pink iggy']. For some reason they have a display of replica primate skulls and an exhibition on Paul Sereno, both of which look totally out of place.
All in all, the entire conference ran smoothly and was a great success. I really enjoyed it and got a lot out of it, and everyone else I spoke to said likewise. We were supported, not only by the Geological Society's History of Geology Group, but also by the Dinosaur Society (which does still exist) and some oil companies. It was a neat social gathering, and special thanks to those who attended after hearing about the meeting here at Tet Zoo. Thanks also to the kind individuals who provided me with bed and board, and to Dick Moody and the other organisers for making it all happen.
Yikes, have to be up in three hours...
Refs - -
Bakker, R. T. 1968. The superiority of dinosaurs. Discovery 3 (2), 11-22.
- . 1971. Dinosaur physiology and the origin of mammals. Evolution 25, 636-658.
- . 1972. Anatomical and ecological evidence of endothermy in dinosaurs. Nature 238, 81-85.
- . 1975. Dinosaur renaissance. Scientific American 232 (4), 58-78.
Christiansen, P. & Bonde, N. 2000. Axial and appendicular pneumaticity in Archaeopteryx. Proceedings of the Royal Society of London B 267, 2501-2505.
Halstead, L. B. 1975. The Evolution and Ecology of the Dinosaurs. Peter Lowe, London.
O'Connor, P. 2006. Postcranial pneumaticity: an evaluation of soft-tissue influences on the postcranial skeleton and the reconstruction of pulmonary anatomy in archosaurs. Journal of Morphology 267, 1199-1226.
Weigert, A. 1995. Isolated teeth of cf. Archaeopteryx sp. from the Upper Jurassic of the coalmine Guimarota (Portugal). Neues Jahrbuch fur Geologie und Paläontologie, Monatshefte 1995, 562-576.
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Off the back of discussions at the Munich meeting, I can confirm that an English version of Peter's Archaeoptery book is in the works, not porjected to be ready until next year though sadly. Still, I have got my hands on some pages and it looks awesome. German speakers can order it online already.
Dude (looks at Pterdactylus drawing) what the hell is that!?
And Dave thinks that something like that could fly? It looks like it would be more at home in Wonderland.
Excellent review, couldn't have put it better myself!
Bizzare, but no more than Helmeted Guineafowl.
Anybody other than Dave Peters tried his techinque of scanner fossil watching?
Your efforts are appreciated, Darren - even if you're just telling us furry tales...!
per jura:
"Dude (looks at Pterdactylus drawing) what the hell is that!?
"And Dave [Peters] thinks that something like that could fly? It looks like it would be more at home in Wonderland."
not being a paleontologist, this stumped me. i googled the name.
to those in-the-know: would i be mistaken if i suggested that dave peters is to pterosaur paleontology what [insert name of token young-earth creationist here] is to the study of evolutionary biology?
Spelling: Kösemen, Niels (with "ee", not with "eye").
Also note the little Nephthys in there.
Yes, I have, on his own photos. I'll post the link later. He has replied; I have yet to read that reply...
No, he isn't dangerous.
People!!! Specialists!!!
Great sorry, sorry, sorry for the terrible offtopic, but I need info very much!!!
Now I prepare a review of cetacean evolution and creationist accusations to it. I found a plenty of material on Indohyus, Pakicetus, Ambulocetus and some other ones. But I have some problems in my work, like these ones:
1) Very poor information about the origin of modern groups of whales and the connection between Archaeoceti and modern suborders of cetaceans;
2) The variability of early Oligocene cetaceans and their relations with later groups of whales;
3) The age of some archaeocetes. In the article Overselling the whale evolution by Ashby L. Camp (published in 1998) there is the information:
***
The generally accepted order of the archaeocete species, in terms of both morphological (primitive to advanced) and stratigraphical (lower/older to higher/younger) criteria, is Pakicetus, Ambulocetus, Rodhocetus, Indocetus, Protocetus, and Basilosaurus (see note 16). One problem for this tidy picture is that the stratigraphical relationships of most of these fossils are uncertain.
In the standard scheme, Pakicetus inachus is dated to the late Ypresian, but several experts acknowledge that it may date to the early Lutetian.[] If the younger date (early Lutetian) is accepted, then Pakicetus is nearly, if not actually, contemporaneous with Rodhocetus, an early Lutetian fossil from another formation in Pakistan.[] Moreover, the date of Ambulocetus, which was found in the same formation as Pakicetus but 120 meters higher, would have to be adjusted upward the same amount as Pakicetus.[...] This would make Ambulocetus younger than Rodhocetus and possibly younger than Indocetus and even Protocetus.[]
In the standard scheme, Protocetus is dated to the middle Lutetian, but some experts have dated it in the early Lutetian.[] If the older date (early Lutetian) is accepted, then Protocetus is contemporaneous with Rodhocetus and Indocetus. In that case, what is believed to have been a fully marine archaeocete was already on the scene at or near the time archaeocetes first appear in the fossil record.[]
(References omitted P. V.; there is no answer yet at the Askabiologist forum)
***
4) The origin of similarity in dentition of mesonychids and early whales how to explain it from the evolutional point of view? Earlier the similarity of their teeth was an argument of the mesonychian ancestry of whales, and the creationist John Woodmorappe in the article Walking whales, nested hierarchies, and chimeras: do they exist? tries to use it for the proving of creation:
***
Alternatively [in case of the inheriting of double-pulleyed astragalus from artiodactyls P. V.], the cetacean-like teeth of mesonychians must be the product of convergent evolution (). The latter rationalization, in fact, is the one that appears widely accepted by evolutionists. Such thinking constitutes a revolution of sorts in mammalian paleontology. Prior to the recent turn of events, teeth had been used for construction of mammalian phylogenies, more or less uncritically, for over a century. All this time, dental features had been generally considered too detailed to be capable of being duplicated independently via convergent evolution.
***
So, thats all at least, at this stage of the article preparing You may think it is idle work to discuss with creationists. But I try to do my work not for them (there is a proverb in Russia: The cut out chunk will not adhere back, and I think creationists are cut out chunks), but for people who may fall under their influence.
So, if you dont whant to proceed the offtop here, send me emails to sivatherium(a)land.ru
I may promise only adequate translation and the mention of the author of the information (article, etc.), because I work not for money, but for idea.
It would be futile to reconstruct angels as physical beings...they were pure spirits.
Most didnt have wings anyway.
Stratigraphy doesn't matter all that much -- the tree of life is just that, a tree, not a ladder --, but I bet that a lot of new information has surfaced since 1998! I mean, that was ten years ago! :-)
This has improved pretty drastically in the last 10 years. Try to find information on the toothed carnivorous mysticetes like Janjucetus... Aetiocetus, the odontocete with baleen, is here.
Convergence. :-|
Yep, that was a mistake. The whole idea of "reliable characters" is precladistic. Relying only on a selected set of characters does not work; all of the evidence must be taken into account.
Dave Peters has some interesting ideas. "Interesting" taken here to mean "Dude, what are you on?
Dave Peters has been a regular correspondent of the Dinosaur Mailing List for a number of years - if you want more information on his interpretations of pterosaurs, you may want to go to the DML archives and run a search.
Thank you, David, but as for Aetiocetus, creationists say: "It was just baleen whale having teeth".
re: David Peters. I've been following the David Peters / the Paleo community dialogue on DML (dialogue that sounds a bit ill-tempered on both sides at times, I regret to say) for a while. Peters doesn't sound like a TOTAL nut, and his dedication to his research project would do any professional proud. Does anyone know his background? Does he have some training in paleontology, or is he a complete autodidact?
re: Archeoceti. The switch from "whales are derived Mesonychians" (orthodoxy not many years back on basis of morphology) to "whales are artiodactyls" (now I think the majority view, suggested first by molecular studies with morphological evidence just beginning to come in) seemed quite dramatic, and it wouldn't be surprising if well-informed creationists jumped on it ("See, the evolutionists are making it up as they go along: even they have admitted that the sort of evidence they used to cite for a whale-Mesonychian link is inconclusive!"). I think it's worth pointing out that in one sense it isn't THAT big a shift: my impression is that, both before and after, the view has been that Mesonychians and Artiodactyls are quite closely related: that, asked to choose from other taxa well represented in the early Eocene, paleontologists might reasonably identify Mesonychians and early Artiodactlys as sister taxa.
I both liked and respected Dave's earlier work on pterosaur reconstruction (back in the days of pterosaurinfo.com).
It was really just when he started "seeing" things in the fossils through the use of hi-res images and Photoshop, that it started looking like he was going off the deep end.
No intended offense to Dave himself. I've corresponded with him a few times and followed him on the DML. He always comes off as a very nice, and dedicated fellow. There's just certain things about this new Photoshop angle that don't quite sit right.
Just a quick addendum. Technically I could say I like and respect Dave's earlier work. I was having a tenses issue.
Also, I believe Dave's earlier site was Pterosaur.com, which later became pterosaurinfo.com...I think.
Darren wrote:
Ogden Nash wrote:
About Dave Peters:
OK. I am asking now only about his method. He makes extremely high resolution scan of a fossil, and looks at fine irregularities of grains of rock around the skeleton. The idea is that layup of sediment preserves outline of decomposed soft parts. As a scientific hypothesis or method, it seems totally plausible. And is reproducible. The guy probably misinterprets or overinterprets results. I ask - did anybody else try his method and what he/she seen?
Chris Bennett did a critique of Peters' tracing method in relation to Anurognathus ammoni that you can read here.
Thanks!
Curiously, Bakker's classical skinny Deinonychus is also now outdated.
Here is part of a message I once submitted to the DML on Dave Peters and his methodology...
---------------------
David: obviously your efforts to document pterosaur phylogeny and origins by way of comprehensive character analysis are worthwhile pursuits. While there is still some completed work to appear on how your proposed phylogenetic schemes match up with the evidence (recall that Dave Hone referred to unpublished material in his phd thesis), I would argue that there is a very good reason why your phylogenies are not being accepted as the most parsimonious: this is because your choice of characters, and coding of them, rests on your photo-interpretation technique. I've said it before and I'll say it again (and everyone else I've spoken to says the same) - none of us hold any confidence in your many unique interpretations of pterosaur bones and teeth, soft tissue crests, frills and tail-whips, multiple babies etc. Every time I (or anyone else I've heard from) looks at pterosaurs, Longisquama, Sharovipteryx, Huehuecuetzpalli or whatever, we come away rejecting your multiple unique interpretations. As discussed in personal correspondence, I have found that your photo-interpretation method has led you astray on Istiodactylus, Tupuxuara, and Solnhofen Pterodactylus and Rhamphorhynchus specimens, and I have heard likewise from workers with first-hand experience of the Triassic taxa that are integral to your prolacertiform/squamate origins hypothesis. You are coding characters and character states that are not present.
The conclusion is that your data sets are cluttered with a significant amount of irrelevant noise (I'm not sure how much, but recall it looking like more than 50%), hence the lack of acceptance. Sorry, but my ideas on this haven't changed, nor have those who have criticised this aspect of your work in the past. And this isn't me being nasty, as I was initially really impressed with your 'four prolacertiforms' paper.
So what? They're wrong, and you can explain why they're wrong. Tell them that toothed whales and baleen whales differ in more than just these two characters.
Besides, a baleen whale with teeth ought to make them pause, too! Again: Janjucetus.
The latter.
No, he does not make extremely high-resolution scans, nor are they of fossils. He takes low-resolution photos from the literature, scans them in, descreens them to remove the pixelization -- which is counterproductive, because it pretends to add information, when in fact it removes information.
I repeat: He never looks at the fossils themselves. He only looks at published photos.
Not when the "decomposed soft parts" are supposed to be entire skeletons that are supposed to have been somehow unossified!
Neither when the matrix is below the level of the fossil. Remember the Nyctosaurus specimen with the outrageous crest? He saw all manner of things around the skeleton -- even though the matrix around the skeleton had been prepared away.
I have tried, and I'll show you the results later today. The results are not reproducible because the method is a Rorschach test.
OT, but regarding bones, tissues and cetaceans: a necropsy of a (balleen) pygmy right whale, shows flattened ribs, laryngeal air sac, blowhole etc. at the Te Papa blog:
whale dissection link
Thank you for nice photo of the hair of baleen whale!
And how to pronounce correct the name of Janjucetus???
Mr. Naish, and what about to tell anything about fossil whales?
(;-)))
Mr Naish says.. answering your questions properly would require me to write an entire article on the subject. I'm happy to do that, of course, but I'm kind of busy right now (and, sorry, planning to cover other stuff at Tet Zoo). In the meanwhile, I would direct you to the following literature... some of which is freely available on the web...
Fitzgerald, E. M. G. 2006. A bizarre new toothed mysticete (Cetacea) from Australia and the early evolution of baleen whales. Proceedings of the Royal Society, London B 273, 2955-2963.
Gatesy, J. & O'Leary, M. A. 2001. Deciphering whale origins with molecules and fossils. Trends in Ecology & Evolution 16, 562-570.
Geisler, J. H. & Uhen, M. D. 2003. Morphological support for a close relationship between hippos and whales. Journal of Vertebrate Paleontology 23, 991-996.
Gingerich, P. D. 2002. Progress on the origin of whales. Geoscience News, University of Michigan Winter 2002, 7-11.
- . 2003. Land-to-sea transition of early whales: evolution of Eocene Archaeoceti (Cetacea) in relation to skeletal proportions and locomotion of living semiaquatic mammals. Paleobiology 29, 429-454.
- ., ul Haq, M., Zalmout, I. S., Khan, I. H. & Malkani, M. S. 2001. Origin of whales from early artiodactyls: hands and feet of Eocene Protocetidae from Pakistan. Science 293, 2239-2242.
Madar, S. I., Thewissen, J. G. M. & Hussain, S. T. 2002. Additional holotype remains of Ambulocetus natans (Cetacea, Ambulocetidae), and their implications for locomotion in early whales. Journal of Vertebrate Paleontology 22, 405-422.
Nummela, S., Hussain, S. T. & Thewissen, J. G. M. 2006. Cranial anatomy of Pakicetidae (Cetacea, Mammalia). Journal of Vertebrate Paleontology 26, 746-759.
O'Leary, M. A. 1999. Parsimony analysis of total evidence from extinct and extant taxa and the cetacean-artiodactyl question (Mammalia, Ungulata). Cladistics 15, 315-330.
- . 2001. The phylogenetic position of cetaceans: further combined data analyses, comparisons with the stratigraphic record and a discussion of character optimization. American Zoologist 41, 487-506.
- ., Gatesy, J. & Novacek, M. J. 2003. Are the dental data really at odds with the molecular data? Morphological evidence for whale phylogeny (re)reexamined. Systematic Biology 52, 853-864.
- . & Geisler, J. H. 1999. The position of Cetacea within Mammalia: phylogenetic analysis of morphological data from extinct and extant taxa. Systematic Biology 48, 455-490.
Thewissen, J. G. M. & Bajpai, S. 2001. Whale origins as a poster child for macroevolution. BioScience 51, 1017-1029.
- ., Cooper, L. N., Clementz, M. T., Bajpai, S. & Tiwari, B. N. 2007. Whales originated from aquatic artiodactyls in the Eocene epoch of India. Nature 450, 1190-1195.
- . & Williams, E. M. 2002. The early radiations of Cetacea (Mammalia): evolutionary pattern and developmental correlation. Annual Review of Ecology and Systematics 33, 73-90.
- ., Williams, E. M., Roe, L. J. & Hussain, S. T. 2001. Skeletons of terrestrial cetaceans and the relationship of whales to artiodactyls. Nature 413, 277-281.
That's just a quick list, there's lots more to check. I note that an impressive amount of 'creation science' crap has started to appear on fossil whales - all devoted, of course, to showing that proto-whales aren't really proto-whales - so it's important to combat it.
Looks like I missed out, wish I could have made it.
And at the risk of looking like Im groverling for forgiveness from Darren check out his paper in Geology todays 'fossils explained' series
Naish,. D., Fossils explianed: ancient toothed whales, Geology Today, Vol. 20, No. 2, March-April 2004
Its a good summary - well I got a good mark in my BSc exam using it anyway...
The promised links to my opinions on some of David Peters' tracings:
http://www.unet.univie.ac.at/~a0000265/tracings/arthurdactylus.htm
http://www.unet.univie.ac.at/~a0000265/tracings/cycnorhamphus.htm
http://www.unet.univie.ac.at/~a0000265/tracings/dimorphodon.htm
http://www.unet.univie.ac.at/~a0000265/tracings/haopterus.htm
http://www.unet.univie.ac.at/~a0000265/tracings/mpum_6009.htm
http://www.unet.univie.ac.at/~a0000265/tracings/noripterus.htm
http://www.unet.univie.ac.at/~a0000265/tracings/pterodaustro.htm
http://www.unet.univie.ac.at/~a0000265/tracings/scaphognathus.htm
http://www.unet.univie.ac.at/~a0000265/tracings/sordes.htm
The disclaimers made above apply. I haven't even checked if the links all work; please tell me.
Bad news: none of the links work. None.
> prolacertiform/squamate origins hypothesis
Prolacertiformes, in spite of their name, are archosauromorphs, and not closely related to squamates. Both are diapsids, but that's all.
Hi Johannes. You've misunderstood I think. Dave Peters originally promoted the view that pterosaurs are nested within Prolacertiformes (though the group he had in mind would now be termed Protorosauria, given that Prolacerta appears close to archosaurs and is not part of the same clade as Protorosaurus and the tanystropheids). While he continues to regard this as the case (though he now regards Protorosaurus as well away from other taxa usually included within Protorosauria), he has more recently argued that his 'prolacertiform' + pterosaur clade is nested within Squamata. I base this on the most recent version of his cladogram, presented at the Munich 2007 pterosaur meeting. More on protorosaurs here soonish, by the way.
> More on protorosaurs here soonish, by the way.
:-) Yeah! More obscure Permo-triassic hellasaurs (hums: I'm not a lizard, not yet an archosaur)!
Links don't work, but thanks, I made my mind already :)
The links didn't work because I had... completely forgotten to, you know, actually upload the files. The links work now.
However, they presuppose that you know the rest of the discussion and have seen the original tracings. So, please start here and check its link out, then go here, and then here.
Please excuse the ugly background.
Thank you, Darren! And the next question about your old article about cetacean evolution: what is the name of the whale evolved trunk? I translated a part of that article, but the trunked (proto-)whale remained a kind of mystery for me.
The trunked stem-whale is Makaracetus bidens.
The .pdf is here.
Thank you!
Speaking of unusual views of prehistoric reptiles (and ammonites) while googling for images to compare with this week's quiz, I found that Klaus Ebel has rather unusual ideas about the mode of life of dinosaurs, returning theropods, sauropods and several ornithopods to the water, based on comparisons with several rather specialised modern taxa. Unfortunately as I don't read German (nor do I know much about biomechanics), I can't adequately criticise his theses, other than to say everything else I've seen makes me think he's flat out wrong.
And his ideas on the mechanics of pterosaur and early bird flight don't sit well either.
Ah yeah. I actually liked his paper on Archaeopteryx (N. Jb. Geol. Paläont. Abh. December 1996, in Engrish), but the DML's resident aerodynamicist says the math rests on a few flawed assumptions, and last time I visited his website he had never heard of hyposphene & hypantrum and therefore seriously believed saurischians had no means of keeping their vertebral columns from sagging! He also seemed to have no idea that the science of sedimentology existed. After a short conversation (he had found a DML post of mine), I wrote a very long e-mail in reply to his website, and then the computer crashed. Looks like I have to try again one day.
Biggest flaw in the paper on Archie (and long-tailed pterosaurs): he doesn't say how he found out where all these animals had their center of gravity; probably he didn't find it out but just guessed. Failure of peer-review.
I wonder what he would make of most mammal vertebrae. Clearly without massive neural spines they can't be terrestrial either. And yet somehow they are.
I'm reasonably open to the idea that Archaeopteryx had a similar mode of life to a dipper or puffin(underwater swimming using the wings) but would like to see rather more detailed comparisons of wing shape before committing any further.
About Dave Peters:
He really is a nice guy and is fully willing to discuss and talk with you and your theories (even about his theories) at leisure. I met Dave before the photointerpretive technique began to be employed, and we discussed the identity of elements of the Batrachognathus skull in some depth, but I've not had the opportunity to sit down and retrace his observations, though I have used some similar techniques in piecing out elements of the Protarchaeopteryx robusta skull, counting "dentition", etc. Dave is also aware that people don't believe in his position, and that some people have not bitten his technique. He chalks this up as because there are too many people who are not willing to try his technique as he does it.
So far, no one I know of has tried to do a double-blind test of the technique, allowing third parties to take pieces of specimens at high resolution, use the technique, and compare with strict visual observation. This would actually take a lot of money or a reasonably-sized collection of specimens from different sedimentologic and depositional regimes.
One of the biggest problems here is that Dave is not a geologist, and while some of us have not held this against him, his strategy requires some knowledge of the method by which these fossils arrive in their current condition, including the process of slab-splitting and irregular preparation.
Sorry!!! Aetiocetus is not an odontocete, it's a mysticete!!! I had misinterpreted the Laelaps post (which calls it a toothed whale, which it is... it's a whale, and it has teeth...). I'm now finally reading the paper. Aetiocetus is even more closely related to the toothless mysticetes (Eomysticetus, Cetotheriidae, and the crown-group) than Janjucetus and Mammalodon are.