Tetrapod Zoology

i-1fae8a9622bafd6f8857bf8fa9388f65-ichthyosauria ver 2 resized.jpg

You wouldn’t know it from Tet Zoo’s content, but for many, many months now I’ve been working continually on ichthyosaurs, the ‘fish lizards’ of the Mesozoic. I’m not ready to talk about the project yet, but will do at some stage. An awful lot has happened on ichthyosaurs since the late 1990s, mostly thanks to the research of Ryosuke* Motani and Michael Maisch and their collagues, but to be honest things have become quieter in the last few years and we certainly are not in any sort of ‘ichthyosaur research renaissance’ as we are with plesiosaurs, dinosaurs, pterosaurs and Mesozoic crocodilians. Here in Britain for example, I’m not aware of anyone doing a devoted post-grad project on Ichthyosauria…

When it comes to any given tetrapod group, most interested people have some sort of ‘working cladogram’ in their heads.. alas, this seems not to be the case for ichthyosaurs. Let’s face it, you need to have kept a pretty good eye on the literature to know what’s going on. The above composite (taken from a talk I give on ichthyosaur diversity and evolution) shows, approximately, the current state of affairs: it is both highly simplified (with loads of taxa left out), and ‘consensus’ (viz, sort of a ‘best fit’ cladogram, as different studies have argued for different patterns of relationship). I include it here only as a pretty picture, as I know it’s too small for the text to be easily seen. I’ll follow up on all of this at some stage. Finally, the little images used above come from various sources and I apologise for stealing the work of various artists: many are by Ken Kirkland and come from Richard Hilton’s excellent Dinosaurs and Other Mesozoic Reptiles of California (2003, Uni Calif Press), the Stenopterygius is by Greg Paul, and the Leptonectes is by John Sibbick. Various others come from wikipedia. It’s very difficult to find accurate restorations of ichthyosaurs – most of what’s out there is awful – and what you see above includes the best of the best.

* Pronounced something like ‘rle-o-ski’ (pers. comm., so don’t argue).

Coming next very soon: marsupial bears, marsupial dogs, marsupial cats, marsupial weasels!

Comments

  1. #1 Adam Pritchard
    June 21, 2008

    Cool! Any information about ichthyosaurs is great.

    That cladogram raises two questions for me:

    1. I notice that Hupehsuchus is not on the cladogram, despite its being labeled as a potential basal ichthyopterygian. What is its current status?

    2. The animal just basal to what appears to be Shonisaurus and Shastasaurus does not appear to have any hindlimbs. What on Earth is it?

  2. #2 Mike Keesey
    June 21, 2008

    I have another question about the cladogram: where can I find a full-size version?

  3. #3 Turdus
    June 21, 2008

    I second the last post. I would love to see a full sized version. The one posted is a bit of a challenge for my middle aged eyes!

  4. #4 Zach Miller
    June 21, 2008

    I suspect that Hupehsuchus is not on the list because it’s not an ichthyosaur proper. It’s questionably an ichythiopterygian, though. And we need a full-size version of that picture. Behold–my new wallpaper!

  5. #5 llewelly
    June 21, 2008

    so… which came first, Teleosts or Ichthyosaurs?

  6. #6 Edman
    June 22, 2008

    I fourth that – give us a full size of that picture. It looks like a fantastic wallpaper!

  7. #7 Mark Lees
    June 22, 2008

    I see loads of marsupial stuff coming :)

    I’m curious, we have mammals, fish (teleosts) and amphibians that carry young in pouches – are there/ where there any known instances of reptilian/dinosaurian/avian pouches for carrying young?

    I can think of some fairly good reasons why it doesn’t occur among birds, and I think I’d probably have seen something somewhere if there was serious suggestion of it occuring for any dinosaurs, but what about reptiles more generally? If not is there any obvious functional reason why it should not occur?

    And here’s a fifth call for a bigger version of your beautiful ichthy-cladogram. (You watch, someone will get in there while Im keying away and I’ll just look like a plonker for saying fifth when I actually turn out to be ninth or tenth!)

    Oh, and have I missed something, what was felizkrilll on about?

  8. #8 Smilodon
    June 22, 2008

    A sixth call for a bigger version.

  9. #9 Jerzy
    June 22, 2008

    There is one pouched bird – male South American finfoot, or sungrebe.

    Surprisingly, although it is quite widespread (but very shy) bird, this behavior is poorly studied and was observed in 19. cent., forgotten and rediscovered recently.

  10. #10 Brad McFeeters
    June 22, 2008

    What are the most common mistakes people make when restoring ichthyosaurs?

  11. #11 Jura
    June 22, 2008

    Crocodylians modify the floor of their lower jaw as a pouch for carrying their young, and protecting them. That’s about the only reptilian pouch I can think of.

  12. #12 Andreas Johansson
    June 22, 2008

    Come on Darren, posting a shrunk version of a nice picture like that is just cruel!

  13. #13 Mike from Ottawa
    June 22, 2008

    I’ve been working continually on ichthyosaurs, the ‘fish lizards’ of the Mesozoic.

    Excellent. Not to put pressure on you, but I hope you’re writing a book that will do for ichthyosaurs what Unwin’s ‘Pterosaurs: From Deep Time’ does for pterosaurs. No pressure mind. :-)

    I’m not ready to talk about the project yet, but will do at some stage.

    Of course you will. It’s one of your charms and thus of TetZoo that you bubble with enthusiasm and so enjoy sharing it.

  14. #14 Darren Naish
    June 22, 2008

    Thanks for comments. Assorted responses…

    – Hupehsuchians: while purported to be close to Ichthyopterygia (or Ichthyosauria sensu Maisch & Matzke) by Motani (1999), they are not ichthyopterygians so were not included. The question as to exactly what ichthyopterygians (or hupehsuchians + ichthyopterygians) are remains, though they’re likely to be diapsids.

    – In the cladogram shown here, what is the sister-taxon to the Shonisaurus + Shastasaurus clade, and why does it appear to lack hindlimbs? It’s the Italian shastasaur Besanosaurus leptorhynchus Dal Sasso & Pinna, 1996, and the picture used here is F. Fogliazza’s drawing from Cristiano Dal Sasso’s Dinosaurs of Italy (2004, Indiana Uni Press). It doesn’t lack hindfins, it’s just that the animal is illustrated with the right hindfin seen ‘edge on’. The tail fin is also obscured because of perspective. Incidentally, you can read my review of Dal Sasso’s book here (review is on pp. 79-82). Incidentally # 2, very cool news on shastasaurs due to appear some time this year (hopefully!!).

    – What was ‘felizkrill’ on about? I have no idea, but it was nothing to do with tetrapod zoology. The commenter has been banned.

    – What are the most common mistakes people make when restoring ichthyosaurs? Incorrect proportions and body shapes, incorrect fin shapes, over-simplified skull shapes, wrong numbers of teeth…. the biggest problem is that lots of reconstructed ichthyosaurs are just generic, all-purpose creatures lacking the subtleties and anatomical details present in all taxa, INCLUDING ICHTHYOSAURUS! Of course, we also have the problem that very few of the taxa have been reconstructed in the first place.

    – Am I doing for ichthyosaurs what Unwin’s The Pterosaurs From Deep Time did for pterosaurs? Sorry, but no no no. I can say no more at this time.

    Ref – -

    Motani, R. 1999. Phylogeny of the Ichthyopterygia. Journal of Vertebrate Paleontology 19, 473-496.

  15. #15 Nathan Myers
    June 23, 2008

    I like the new, forward-looking profile. I predict a far-ranging, varied life. Take a good look, we may have the next David Attenborough here. He’ll need to practice starting sentences in Patagonia and finishing them in Iceland.

  16. #16 Andreas Johansson
    June 23, 2008

    He’ll need to practice starting sentences in Patagonia and finishing them in Iceland.

    Learning German would be a good first step.

  17. #17 Zach Armstrong
    June 23, 2008

    Yes, the sungrebe does indeed have pouches (underneath the wings) that carry the young (even during flight (!)). Only the male sungrebe however has these pouches and along with them the special flaps of skin that keep the young in. During flight it is possible to see the little heads of the chicks peeking out.

  18. #18 Jenny Islander
    June 24, 2008

    . . . Wow. That’s just so amazingly bizarre. But why does only the male have them?

    On a vaguely related note, can anybody point me to a decent online summary of the Early Cretaceous flora and fauna of northeastern Africa? I’m interested particularly in Sudan. I get a lot of hits for palynology, but I want something broader.

    Also, another call for a bigger version of the cladogram. Mesozoic sea monsters are so cool!

  19. #19 Tim Morris
    June 24, 2008

    I was wondering about Nannopterygius and exactly how much is known of it, or what indeed it is. were they justified in making a huge illustration of it?

    Any info or links to pictures of material would be good.

  20. #20 Darren Naish
    June 24, 2008

    Nannopterygius is one of my favourites and is known from a complete skeleton (BMNH 46497, currently panel-mounted in the NHM palaeo corridor, about 3 m off the ground), plus two referred, incomplete specimens (neither of which have been properly described). I was going to include it in the cladogram but ended up not doing so because views on what it is differ so wildly: McGowan & Motani (2003) included it among ophthalmosaurids (which looks mightily unlikely to me) while Maisch & Matzke (2000) placed it somewhere near the base of Thunnosauria, near to Suevoleviathan (which is also missing from the cladogram above).

    For those who don’t know, Nannopterygius has to be one of the most remarkable ichthyosaurs: it has tiny, tiny, massively abbreviated limbs, a reduced pectoral girdle with stretched coracoids, slender, cylindrical ribs and evidence for hefty tail musculature. It was weird.

    Refs – -

    Maisch, M. W. & Matzke, A. T. 2000a. The Ichthyosauria. Stuttgarter Beiträge zur Naturkunde Serie B (Geologie und Paläontologie) 298, 1-159.

    McGowan, C. & Motani, R. 2003. Handbook of Paleoherpetology. Part 8. Ichthyopterygia. Verlag Dr. Friedrich Pfeil, München.

  21. #21 Augray
    June 24, 2008

    I, too, await a full-sized version of the cladogram. What the heck is that thing in the upper right corner? It looks like an ichthyosaur crossed with a deep sea fish.

    As for the question of what ichthyopterygians are, I’m reminded of a comment that Richard Forest made at http://groups.google.ca/group/talk.origins/msg/e22f60e54d3a6a2e

  22. #22 Darren Naish
    June 24, 2008

    Upper right-hand corner animal is Platypterygius, the ‘Cretaceous ichthyosaur that’s everywhere’.

    Without meaning to diss my good friend Richard, the old idea that ichthyosaurs are not clearly reptiles and might as well be basal tetrapods or something is woefully out of date (it was promoted in the early 20th century by von Huene and mostly hinges on the presence of folded tooth bases in ichthyosaurs). We now have basal forms with a diapsid skull structure (plus remnants of this condition in later taxa), and ichthyosaurs also resemble diapsids in palatal morphology. Most/all studies that have coded characters from diverse tetrapod clades find ichthyosaurs close to, or part of, the lepidosaur-archosauromorph clade (which has unfortunately been named Sauria).

  23. #23 Augray
    June 24, 2008

    Now that I know the name Platypterygius, I’ve found a larger version of the image, and I realize that the picture isn’t quite what I thought it was. I assumed that the image was a profile, whereas in reality the animal was shown in the middle of a turn. Everything makes sense now, and it’s not as freaky as I thought.

    I don’t think that Richard (and my apologies to him for misspelling Forrest) took the idea that ichthyosaurs are amphibians that seriously. But it certainly made me think “outside the box” for a few minutes. And given the news group that we were posting on at the time, that’s to be expected/encouraged. Thanks for the phylogenetic clarification.

  24. #24 Christophe Thill
    June 24, 2008

    Darren, although I love ichtyosaurs just as anyone else, I’m impatient to read the marsupial stuff. I’ve had an online conversation with someone (a biologist, apparently), who talked about the superiority of placentals on marsupials as a “scientific consensus”, stating that kangaroos wouldn’t last long if transplanted in the African savannah. All this anti-pouchism always makes me sad. I tried to play the (Tasmanian, of course) devil’s advocate, but to no avail. So I’ll be glad if you can slip a few words about this Great Debate…

  25. #25 Michael Anderson
    June 25, 2008

    Darren, if it’s the case that copyright issues are preventing you from publishing a bigger version of the cladogram, please just say so. It does look amazing. Cheers, Mike.

  26. #26 Michael Anderson
    June 25, 2008

    Oh and PS – I am from Alberta originally, living in BC now and making a pilgrimage to the Tyrell next week to see the Shonisarus, debuting Friday. If you’d like some pics please let me know.

  27. #27 Zach Miller
    June 25, 2008

    I would definately like some pics, Michael. Shoni is one of my favorite icthyosaurs, but not because it’s so huge, rather, because it has such strange proportions and such a deep body.

  28. #28 Michael Anderson
    June 26, 2008

    Zach (and anyone), drop an email to michael.h.anderson at mckesson dot com and I’ll fire you some after I get back (July 18). Please specify if you want full resolution or desktop wallpaper :)

    I have followed the Shoni story since excavation began – the funny thing is this trip to Alberta has been planned for months, but I only found out about the debut at Tyrell last week. Nice coincidence.

  29. #29 Valentin Fischer
    June 29, 2008

    Hi Darren,

    If I read correctly, you place the genus Excalibosaurus in the picture, but this genus isn’t one anymore, because it is considered as juvenile Eurhinosaurus by Maisch & Matzke (2000) if i remember correctly.

    PS: I’m the guy from Belgium who sent you an e-mail 2 weeks ago about Ph D’s in england on “eotyrannus@gmail.com” but received no answer, it this adress correct?

  30. #30 Darren Naish
    June 29, 2008

    Hi Valentin. Sorry for my lack of response to your email – I’m afraid your message is in a long queue and I haven’t gotten round to dealing with it. Please don’t take this personally.

    You are correct about Maisch & Matzke’s (2000) proposal that Excalibosaurus is synonymous with Eurhinosaurus. However, this was contested by McGowan (2003) and McGowan & Motani (2003). Maisch & Matzke argued that the two were essentially the same, only differing in the extent of the overbite. The new specimen described by McGowan (2003) showed that this is not correct: they differ in vertebral count and limb morphology, and the overbite doesn’t just differ in extent, but in how it has been achieved (Eurhinosaurus has a drastically shortened lower jaw, for example).

    Refs – -

    Maisch, M. W. & Matzke, A. T. 2000. The Ichthyosauria. Stuttgarter Beiträge zur Naturkunde Serie B (Geologie und Paläontologie) 298, 1-159.

    McGowan, C. 2003. A new specimen of Eurhinosaurus from the English Lower Jurassic. Journal of Vertebrate Paleontology 23, 950-956.

    - . & Motani, R. 2003. Handbook of Paleoherpetology. Part 8. Ichthyopterygia. Verlag Dr. Friedrich Pfeil, München.

  31. #31 Valentin Fischer
    June 29, 2008

    Yes the famous ichthyosaur war :) I don’t know who to trust anymore. I ‘ve just checked the Mc Gowan paper of 2003. I think the extend of the lower jaw can be a poor character, but the fin elements are really different, that’s totally right!

    It’s great to have such a great person to talk to about ichthyosaurs, it keeps me improving!

  32. #32 Clive Owen
    July 8, 2008

    Any news on the ichthyosaur project which you said you were working on but were a bit mysterious about?

  33. #33 Michael Maisch
    December 28, 2008

    Hiho Darren

    I’d also like to see a bigger version of the splendidly looking cladogram, if it happens that you used some of my stuff (the Temnodontosaurus skull looks familiar^^), I can assist you with any copyright things if necessary.

    And, btw, methinks that Excalibo turned out to be a valid taxon. As long as only its skull and some odds & ends were known it looked pretty much like Eurhinosaurus, but that has changed with the complete skeleton. I listed it as a valid taxon in my Habilitation Thesis which is (and hopefully will remain) unpublished.

    Cheers

    Michael

  34. I know you are extremely busy these days, but I have a Ichthyosaur favour to ask…

    Over on ART Evolved we are doing an Ichthyosaur gallery in June, and as of such we’re starting to get everyone thinking about all things fish lizard.

    You mention above how almost all Ichthyo art is awful. Would I be able to humbly request a simply explanation of either what makes most of the stuff out there terrible, and/or what makes for a good Ichthyosaur reconstruction.

    Which ever is shortest and quickest for you to do (a paragraph version even would go a long way, though should you suddenly find yourself with time to spare, we’d love to host a guest article :P though again the short paragraph version would be more than enough to make you our hero!).

    The net result should hopefully be a couple dozen new totally awesome Naish standard Ichthyosaur drawings entering existence!

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