Friday, November 7, 2014

SVP 2014 Day 2

Continuing from yesterday...

Not a theropod talk, but something very cool indeed.  Does anyone remember Chatterjee's supposed pachycephalosaur domes from the Triassic Maleri Formation of India?  They've never been published, but he apparently mentioned them in his SVP 1998 talk "Dinosaurs in the land of gonds."  There was some talk about them on the DML in 2000 where Weinbaum says they "look exactly like" pachycephalosaur domes, and Olshevsky mentioned Goodwin would classify them as pachycephalosaurian if they were found in the Cretaceous.  Indeed, Goodwin is listed as working with Chatterjee on Indian pachycephalosaurs in the latter's CV.  Well it looks like the mystery has been solved.  Stocker et al. report finding a basal archosauriform from the Dockum Group with a dome convergent with pachycephalosaurids.  "Like pachycephalosaurs, this Triassic specimen preserves a thickened and domed skull roof with obliterated cranial sutures, an expanded posterior margin of the skull (a synapomorphy of Marginocephalia), and large orbits."  They don't mention the Maleri specimen, but the connection seems obvious.  How ironic this was found in the Dockum, where Chatterjee did tons of work.

Makovicky et al. have a poster on dinosaurs from the Mussentuchit Member of the Cedar Mountain Formation in Utah and report on the partial skeleton of a giant oviraptorosaur.  They say "a midcaudal vertebra is highly pneumatic, and a series of four distal caudals form a pygostyle-like structure", so it's probably a caenagnathoid or close relative.  This is interesting, as the material is Albian, so is earlier than known caenagnathoids.  Because Macroelongatoolithus shells were found close by, the presenters think it may belong to this taxon.

Again not theropodan, but just amusing.  On page 137, Gerwitz and Green had an abstract about change in size throughout time in Florida deer bones, but there's a huge WITHDRAWN plastered over it.  Apparently it was supposed to be a poster on Thursday.  I've never seen a withdrawn presentation at SVP, and wonder what the story is behind what seems like an innocuous statistical study.

Good thing I padded this entry, since it seems Thursday was basically bereft of Mesozoic theropod talks.  In other news, I finished coding Deinocheirus today and it emerged in a different position than found by Lee et al. or Andrea's post.  Maybe the Angeac taxon or Datanglong will affect things, so I'm adding them now.


3 comments:

  1. "Like pachycephalosaurs, this Triassic specimen preserves a thickened and domed skull roof with obliterated cranial sutures, an expanded posterior margin of the skull (a synapomorphy of Marginocephalia), and large orbits."

    Unlike pachycephalosaurs, it has a huge hole for the pineal foramen in the dome. The dome is basically a ring around a huge crater; reminded me of the occipital condyle of immature Diadectes (it is a condyle, not a cotyle, but it mostly consists of the notochordal pit).

    I've never seen a withdrawn presentation at SVP

    Seriously? Easily 10 posters were withdrawn this year, replaced by "WITHDRAWN" in the schedule and a sheet saying "This poster has been withdrawn." in the actual poster session.

    Problems with traveling could be to blame. Two talks I heard were previously recorded videos because the author couldn't be present – the one from China, in any case, ended up not getting his visa.

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    1. The Triassic bone-headed archosauriform is now officially published online:

      Michelle R. Stocker; Sterling J. Nesbitt; Katharine E. Criswell; William G. Parker; Lawrence M. Witmer; Timothy B. Rowe; Ryan Ridgely; Matthew A. Brown (2016). "A Dome-Headed Stem Archosaur Exemplifies Convergence among Dinosaurs and Their Distant Relatives". Current Biology. in press. doi:10.1016/j.cub.2016.07.066.

      I spoke with Sankar Chatterjee about Triopticus and its potential resemblance to the "Triassic pachycephalosaur" from India and he agrees with me that Triopticus and the "Triassic pachycephalosaur" are closely related to each other.

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  2. "Seriously? Easily 10 posters were withdrawn this year, replaced by "WITHDRAWN" in the schedule and a sheet saying "This poster has been withdrawn." in the actual poster session."

    Sure this year, but I meant in previous years. There are no presentations listed as withdrawn in the previous decade's abstract volumes.

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