Within the last week, there's been so many fantastic papers out that I literally have no idea where to start. People always seem to publish these things when I am most busy. It is most inconsiderate.
Anyway, together with a few other things I never got round to posting, I thought I might stick a little compendium up of some recent cool papers. I'm not planning on making this a regular feature - especially when you see how committed I am to my other "regular" feature (sorry about that, Helen!). So for this last week, here are my picks from the last week or so of paleontology for you to browse at your leisure.
Pikaia
Conway Morris, Simon, and Jean‐Bernard Caron. “Pikaia Gracilens Walcott, a Stem‐group Chordate from the Middle Cambrian of British Columbia.” Biological Reviews. doi:10.1111/j.1469-185X.2012.00220.x.http://onlinelibrary.wiley.com/doi/10.1111/j.1469-185X.2012.00220.x/abstract.
Simon Conway Morris and Jean-Bernard Caron's paper on Pikaia; which seems to have attracted a lot of attention from the media. They've formally classified it as a bone fide chordate, which would make it the oldest chordate in the fossil record; an ancestor of all vertebrates. To be honest, that was hardly a surprising finding; the really meaty stuff is what they have to say about vertebrate origins in general. It's in biological reviews, so it's a whopper (not many journal articles need a table of contents) but well worth the read.
Yet more tetrapods
Smithson, Timothy R, Stanley P Wood, John E. A Marshall, and Jennifer A Clack. “Earliest Carboniferous Tetrapod and Arthropod Faunas from Scotland Populate Romer’s Gap.” Proceedings of the National Academy of Sciences (March 5, 2012). http://www.pnas.org/content/early/2012/02/27/1117332109.
Jenny Clack and co's latest tetrapod finds plug Romer's gap. Romer's gap now seems to be something of a collecting bias.
Death poses
Reisdorf, Achim, and Michael Wuttke. “Re-evaluating Moodie’s Opisthotonic-Posture Hypothesis in Fossil Vertebrates Part I: Reptiles—the Taphonomy of the Bipedal Dinosaurs Compsognathus Longipes and Juravenator Starki from the Solnhofen Archipelago (Jurassic, Germany).” Palaeobiodiversity and Palaeoenvironments 92, no. 1 (March 1, 2012): 119–168.
Dinosaurs didn't necessarily dye in agony; their poses are more indicative of the bodies entering water. Considering how simple this study was I'm surprised it hasn't been done before.
Mesosaurs may have given birth to live young
Piñeiro, Graciela, Jorge Ferigolo, Melitta Meneghel, and Michel Laurin. “The Oldest Known Amniotic Embryos Suggest Viviparity in Mesosaurs.” Historical Biology (2012): 1–11.
Nice to see some more solid evidence for this.
T-rex bite mechanics
Bates, KT, and PL Falkingham. “Estimating Maximum Bite Performance in Tyrannosaurus Rex Using Multi-body Dynamics.” Biology Letters (2012).
They chomp good.
Bone pneumatization in therapods
Benson, Roger B. J, Richard J Butler, Matthew T Carrano, and Patrick M O’Connor. “Air‐filled Postcranial Bones in Theropod Dinosaurs: Physiological Implications and the ‘reptile’–bird Transition.” Biological Reviews 87, no. 1 (February 1, 2012): 168–193.
I've meant to blog somethime about how we've had rather a bum deal with our lungs, and the pneumatized system that birds have is a much better system, where they have air pockets in many of their bones. What Benson&Butler and co have shown is show that actually, we see this pneumatization did not happen primarily as an adaption to flight. Instead, they show that in large dinos it's much more likely to have been a weight saving device; this is definitely understandable; imagine how heavy some sauropods would be if their bones didn't resemble bath sponges, not to mention that they would probably need to eat more calcium than is in the white cliffs of dover.
However, the really interesting thing is that therepods don't need to get very big before their bones are pneumatized. This is especially true in the lineages closest to avian dinosaurs (birds), but crucially it seems to be that it was simply due to increased metabolic demands and not necessarily flight.
The main thing is, the maniraptoran-bird transition is even more blurred than ever.
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That's not actually it in terms of papers; I do have a proper article in the pipeline coming on the Burgess Shale, which will be out within the next few days. For now, enjoy the papers above, and message me if you have any problems getting hold of them.
I think I mentioned previously that I was archiving things to a new wordpress website; you can find it here
http://oliverspaleoblog.wordpress.com/
I'm also planning on posting things there that won't appear here; mostly some more esoteric articles and slightly more random thought detritus than I already post here.
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