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A Squamotastic Christmas at Tet Zoo

The views expressed are those of the author and are not necessarily those of Scientific American.

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My plan was to get something else finished for Tet Zoo before Christmas but, alas, that just wasn’t possible. So here’s this…

And for those of you who want to see more detail, here are enlarged versions…

And for all of you Squamozoic fans who need a labelled version…

For more on the Squamozoic go here. Of course, what we really need is a Field Guide to the Squamozoic. Maybe one day. Ok, still hard at work here but… best wishes for the Christmas season, and have a great New Year. Lots due to happen in 2014.

Darren Naish About the Author: Darren Naish is a science writer, technical editor and palaeozoologist (affiliated with the University of Southampton, UK). He mostly works on Cretaceous dinosaurs and pterosaurs but has an avid interest in all things tetrapod. His publications can be downloaded at He has been blogging at Tetrapod Zoology since 2006. Check out the Tet Zoo podcast at! Follow on Twitter @TetZoo.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. Heteromeles 11:03 am 12/21/2013

    And a Hippo Gnu Deer to you too, Darren!

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  2. 2. Jerzy v. 3.0. 11:30 am 12/21/2013

    Merry Christmas and Happy New Year, Darren! And all the rest tetrapod lot from this blog ;) !

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  3. 3. CS Shelton 6:23 am 12/22/2013

    Off topic, but I recently followed a link to some aggravating article in the sidebar and left a scathing comment there. It was summarily deleted, while someone else’s post – which was an egregious linkdump to some hippy quantum woo websites – remained unmolested.

    I don’t recommend people read anything else on SA’s network. For me, that stuff has ranged from idiotic to offensive. Waste o’ time.

    But I’ll follow Tet Zoo wherever it goes. <3

    I suppose I should give the other peeps the benefit of a doubt. Is there another blog on SA that does not display all of the worst foibles of contemporary science journalism?

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  4. 4. BilBy 7:08 am 12/22/2013

    Happy Xmas Darren, thanks for all the wonderful articles, and all the new things I learned from this website this year

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  5. 5. naishd 8:02 am 12/22/2013

    Thanks, all, for comments and Christmas wishes – and thanks for words of encouragement, I hope you all continue to enjoy Tet Zoo. Loads more to come…

    CS Shelton – well, I can’t vouch for stuff elsewhere on the network, or to the stuff that gets linked to in non-Tet Zoo sidebars. At least you know that there’s consistent quality content at Tet Zoo, right?

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  6. 6. Jerzy v. 3.0. 12:09 pm 12/22/2013

    @CS Shelton
    Maybe there is another blog worth reading on Scientific American, but I did not find it yet. Up to now, put me off of buying paper version of the magazine.

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  7. 7. ekocak 1:46 pm 12/23/2013

    I love the fact that you managed to work a Tremors reference into this.

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  8. 8. naishd 1:55 pm 12/23/2013

    Ah, you’re referring to the legend that is Graboidus, right? Andrea Cau – it’s pronounced ‘cow’ – published this one a few years back… Which reminds me, I’m going to start a regular slot on the TetZoo Podcast called ‘Cau and Keesey Corner’. Still working on the jingle.

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  9. 9. Yodelling Cyclist 4:15 pm 12/23/2013

    “Bloody Keesey”….;-)

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  10. 10. Yodelling Cyclist 7:16 pm 12/23/2013

    We need more comments: err, why have we not seen any massively marine reptiles post KT? No new mosasaurs, nothing to rival the thallatosuchians despite an apparent head start over the mammals ( in that varna ids were still extant, and there were ocean going crocodiles).

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  11. 11. naishd 7:31 pm 12/23/2013

    Cenozoic marine reptiles: great question. Sea turtles did well, of course (and, indeed, there are Paleogene lineages that didn’t make it into the Neogene), but note that dyrosaurids were important in some Paleogene marine communities (especially Tethyan ones). Then there are the snakes – which reminds me, I have that unfinished article to, err, finish…

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  12. 12. Jenny Islander 9:12 pm 12/23/2013

    We mustn’t forget the mysterious worlds inside the polar circles, where the absurdly high metabolic rates of avians actually confer an advantage. Consider the flocks of squamoas that continually race the edge of starvation in the lands rimming the Arctic Ocean. While their ability to travel at high speed over long distances enables them to exploit widely scattered resources in a climate that is deadly to normal creatures, they must also burn enormous amounts of energy simply to stay warm. These creatures migrate annually into the northernmost fringes of civilization, or we would know nothing about them. But there are hints of smaller, volant avians that never leave the cold reaches: mysterious bones discovered in Ice Age deposits, blurry photographs taken by heavily insulated exploratory teams. And cryptozoologists trade rumors of Antarctic avians that enter the frigid waters. Perhaps further exploration will show us what really lives there–if anything.

    (Disclaimer: IANA biologist, all howlers my fault.)

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  13. 13. Yodelling Cyclist 5:48 am 12/24/2013

    Ms. Islander: I wouldn’t give much heed to such foolishness. This sits along with such speculation as mega mammals (body mass above 10kg) and the fragmentary reports of large mammalian fossils being found. You will note, strangely none of these tantalising reports survive close inspection. The fact that mammals and avians didn’t rise up to dominance post KT rather shows that there is some fundamental constraint preventing such development. Mery Squazmass all!

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  14. 14. Yodelling Cyclist 5:51 am 12/24/2013

    naishd: Am I right in thinking that sea snakes most be quite young? Being limited to the Indo-Pacific rather suggests that they post date the Tethys. And they’re hardly as cool as mosasaurs! :-)

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  15. 15. David Marjanović 8:11 am 12/24/2013

    Today’s sea snakes are elapids. They’re young, and have nothing to do with the mid-Cretaceous sea snakes or the Eocene ones.

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  16. 16. naishd 8:43 am 12/24/2013

    Yes, David beat me to it – the several modern sea snake lineages are very recently evolved members of the elapid radiation… in fact, according to some molecular studies they’re as much a modern invention as are hominins and monodactyl horses: Sanders et al. (2012) found all sea snakes (sans laticaudids) to have evolved within the last 6 Ma, with the majority of lineages having evolved within the last 3.5 Ma!

    I’ve covered sea snakes at Tet Zoo a few times before: some of this was back in 2006 when I was inspired by Rasmussen’s then-newish papers, one of which (Rasmussen 2002) made the proposal that elapid sea snakes might have originated in the Cretaceous. Such an idea is now very much discordant with the data. Outside of Elapidae, there are other marine snake lineages (namely Pachyophiidae and Palaeophiidae), and these really are Mesozoic and Paleogene. Palaeophiids have persisted to the present in the Squamozoic – some are quite large.

    The Tet Zoo sea snake articles are…

    ‘A miniature plesiosaur without flippers’: surreal morphologies and surprising behaviours in sea snakes
    Sea kraits: radical intraspecific diversity, reproductive isolation, and site fidelity
    Tet Zoo picture of the day # 15 (turtle-headed sea snakes)
    Terrestrial elapids, take 2

    Ref – -

    Rasmussen, A. R. 2002. Phylogenetic analysis of the “true” aquatic elapid snakes Hydrophiinae (sensu Smith et al., 1977) indicates two independent radiations into water. Steenstrupia 27, 47-63.

    Sanders, K. L., Lee, M . S. Y., Mumpuni, Bertozzi, T. & Rasmussen, A. R. 2012. Multilocus phylogeny and recent rapid radiation of the viviparous sea snakes(Elapidae: Hydrophiinae). Molecular Phylogenetics and Evolution doi: 10.1016/j.ympev.2012.09.021

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  17. 17. Heteromeles 10:18 am 12/24/2013

    @Jenny: don’t forget the clade of Arctic and Antarctic ice snakes (Cryophidae) that have colonized the edges of the ice in Antarctica, their diversity showing the surprising diversity of niches provided by ice and rock. These two otherwise unrelated offshoots of the Palaeophidiae independently evolved unique sets of adaptations allowing them to stay active in freezing waters. Surprisingly, both clades of ice snakes independently evolved high concentrations of trimethylamine oxide and urea in their blood, an adaptation otherwise found only in Greenland sharks. Indeed, these aquatic serpents die in water much above 10 deg. C.

    Since both clades are air breathing and neither tolerate the warm waters of even the temperate zone, let alone the tropics, the prevailing hypothesis is that they evolved independently at each pole, and that the startling similarities in the pack ice hunting species (originally placed in the genus Glaciodraco by Ssslinnaeus) are an excellent example of convergent evolution.

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  18. 18. Yodelling Cyclist 12:02 pm 12/24/2013

    How do the choristoderes and sebecosuchids fair in the squamozoic?

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  19. 19. Squiddhartha 1:46 pm 12/24/2013

    On topic for Christmas, I was doing some last-minute shopping yesterday at Barnes & Noble and found several copies of Witton’s _Pterosaurs_, which I had bought for myself in the Kindle version some time ago.

    The book is *gorgeous*. I was tempted to buy it despite having read its contents a couple of times. I may yet.

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  20. 20. Heteromeles 6:18 pm 12/24/2013

    Darren, did you include Noeldraco sancti-nicholi in the picture? I’ve always wanted to see one.

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  21. 21. Yodelling Cyclist 6:29 pm 12/24/2013

    @Heteromeles: Is that the one with sensitive white squamofibres protruding from the face?

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  22. 22. Heteromeles 8:58 pm 12/24/2013

    @YC: Yes, that’s the one.

    On a separate topic, what does one call the Arctic and Antarctic in the Squamozoic? The terms refer to the constellation Ursa Major, whose name is based on a mammalian megapredator from the hypothetical Anthropocene. What is the name for the Squamozoic constellation containing Polaris?

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  23. 23. Jenny Islander 11:40 pm 12/24/2013

    What, were you estivating when they covered astronomy in school? Joking, joking. They are the Greater and Lesser Perentotron. Of course, some people trim both constellations to the Big and Little Dippers, but that’s so unpoetic. You can see the long line of the Greater Perentotron, standing on her hind paws, if you begin with the end of the handle of the “Big Dipper” as the beast’s nose, then follow the long line of her back past the rim of the “Dipper” to the trailing tail.

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  24. 24. David Marjanović 7:26 am 12/25/2013

    Surprisingly, both clades of ice snakes independently evolved high concentrations of trimethylamine oxide and urea in their blood, an adaptation otherwise found only in Greenland sharks.

    Urea in the blood is normal for gnathostomes, found today in marine cartilaginous fishes and in Latimeria. It’s a trick to stay iso- or hypertonic in seawater while having ion concentrations low enough not to interfere with the nervous system. I’m not aware of reports of trimethylamine oxide in any other vertebrate, however!

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  25. 25. Lars Dietz 8:45 am 12/25/2013

    David: TMAO is also found in other chondrichthyans and coelacanths. It’s also used for osmoregulation and it’s thought to be a protein stabilizer that counteracts the effects of urea.

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  26. 26. David Marjanović 10:21 am 12/25/2013

    Oh, that finally explains how they survive urea concentrations that would kill us several times over! :-) Thank you!

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  27. 27. Heteromeles 1:54 am 12/26/2013

    Glad to know how it works–I just hauled it off the web. So long as there’s no evo-devo reason why a reptile couldn’t make TMAO, it’s not an impossible adaptation. I just thought it made more sense than suggesting a snake converged on icefish (notothenioid) physiology. That strikes me as a great deal less likely than the (re)evolving TMAO/urea trick for managing cold temperatures, although I wouldn’t mind it if someone demonstrated the reverse was true.

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  28. 28. Christopher Taylor 5:19 pm 12/26/2013

    Just to respond to whether there are other good blogs at Scientific American: I’d recommend Jennifer Frazer’s work at The Artful Amoeba.

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  29. 29. Ausktribosphenos 5:40 pm 01/7/2014

    Fantastic shit!

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  30. 30. Ausktribosphenos 5:41 pm 01/7/2014

    Darren, have you considered making Tet Zoo Posters?

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