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Re: Paul Sereno previews digging raptor and other news



From: Ben Creisler
bcreisler@gmail.com

Many thanks! Use of the term "raptor" is not a reference to
Maniraptora in this case. Here's the full abstract from the 2010 SVP
meeting:


Sereno, P. C. (2010) Noasaurid (Theropoda: Abelisauroidea) skeleton
from Africa shows derived skeletal proportions and function. Journal
of Vertebrate Paleontology, Supplement 30(2):37A.  (50)

An articulated skeleton of a noasaurid theropod from the Elrhaz
Formation (Aptian-Albian) of Niger exhibits derived features in the
axial and appendicular skeleton indicative of fossorial habits in
addition to the unique features of the metatarsus and pelvis that
unite later species from other landmasses. The dorsal vertebrae are
unusually long (centra length more than twice diameter). The ribcage
is reinforced to resist forces generated by the forelimb, including
long and robust posterior cervical ribs, five large uncinate
processes, ossified sternal ribs and sternal plates, and an enlarged
coracoid. As in abelisaurids, the glenoid is directed posteriorly and
only slightly laterally. The forelimb is directed
posteroventrolaterally, is very short (18% of hind limb length), has
intralimb proportions similar to those in abelisaurids, is powerfully
constructed (robust deltopectoral crest and olecranon, broad
interphalangeal joints), and has straight unguals. The forelimb cannot
be flexed anteriorly beyond a coronal plane through the shoulder
joints; it can effect a digging stroke that rotates the large-clawed
manus toward the midline under the trunk. Digit II, the longest manual
digit, preserves a portion of the ungual sheath. The hind limb has
cursorial proportions including a tibia longer than the femur, pedal
digits II and IV markedly shorter than digit III, and short, flat
pedal unguals. The new skeleton, in sum, shows that a greatly
shortened, but powerful, forelimb that lacks a semilunate carpal is
probably primitive for abelisauroids and may have been used in
noasaurids for enlarging burrows in pursuit of prey.




Also:

Keillor, T., Sereno, P., Masek, R. (2010) Range of movement in a
noasaurid forelimb: in situ data and joint reconstruction.Journal of
Vertebrate Paleontology, Supplement 30(2):19A.  (53)



Discovery of a diminutive forelimb on an articulated skeleton of a
noasaurid theropod presented an opportunity to study its range of
motion. In situ orientation and joint spacing was preserved by
preparing a one-piece silicone mold that incorporated a portion of the
adjacent shoulder girdle and ribcage. The forelimb was removed from
the skeleton for further preparation, and the glenoid and sternal
plates were fully exposed. The humerus, radius, ulna, carpus, and
manus were then more fully prepared. A second round of molds and casts
were made from the prepared limb elements. After study of opposing
joint surfaces, joint spacing and movement were restored by embedding
mechanical joints composed of 3-4mm stainless  steel ball studs into
sockets. The finished jointed and poseable forelimb model enhances
visualization of the relation between joint surfaces and exploration
of range of motion and the positioning of the strongly-clawed manus.
Forelimb manipulation of live crocodilians and dissections of chicken
and alligator shoulder and elbow joints provided comparative data on
range of motion, joint spacing, and articular cartilage.

(And apologies for the earlier typo --- "Senero" should be Sereno of course!)

On Sat, Mar 8, 2014 at 3:49 PM, Thomas R. Holtz, Jr. <tholtz@umd.edu> wrote:
> The "digging raptor" was described at SVP a few years ago. It is the most
> complete noasaurid found so far.
>
> Sereno, P. C.  Noasaurid (Theropoda: Abelisauroidea) skeleton from Africa
> shows derived skeletal proportions and function. Journal of Vertebrate
> Paleontology, Supplement 30(2):37A.  (50)
>
> On Sat, March 8, 2014 12:20 pm, Ben Creisler wrote:
>> From: Ben Creisler
>> bcreisler@gmail.com
>>
>>
>> A number of recent news items:
>>
>> Last night (3-7-2014) Paul Sereno gave a talk in Seattle that included
>> images of a reconstructed skeleton (along with animation) for a
>> "digging raptor" from the Sahara that is yet to be officially named or
>> described. He characterized the theropod as a cross between a rhea and
>> a wolverine--with very long hind legs but short robust forelimbs,
>> braced with a powerful sternum and shoulder area. The animation showed
>> it digging into a small mammal burrow with its long back legs crouched
>> flat. This combination looks similar to the one  found in
>> alvarezsaurids--a lightly built running body with long legs, and very
>> short forelimbs.  However, the digging raptor has three large flat
>> digits on its hand rather than a single massive claw. Apparently this
>> dinosaur had been briefly mentioned before as far back as 2012. He
>> implied that it will be out soon. I'm not aware of any online material
>> or links.
>>
>> Senero hinted that much new Spinosaurus material is about to be
>> announced as well. It will change some details of how Spinosaurus has
>> been reconstructed and will make it the biggest known theropod.
>>
>> https://www.burkemuseum.org/events/browse/unearthing_africa_talk
>
> Thomas R. Holtz, Jr.
> Email: tholtz@umd.edu   Phone: 301-405-4084
> Office: Centreville 1216
> Senior Lecturer, Vertebrate Paleontology
> Dept. of Geology, University of Maryland
> http://www.geol.umd.edu/~tholtz/
> Fax: 301-314-9661
>
> Faculty Director, Science & Global Change Program, College Park Scholars
> http://www.geol.umd.edu/sgc
> Fax: 301-314-9843
>
> Mailing Address:        Thomas R. Holtz, Jr.
>                         Department of Geology
>                         Building 237, Room 1117
>                         University of Maryland
>                         College Park, MD 20742 USA