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RE: Concavenator corcovatus, a new humped carcharodontosaurid from Las Hoyas



Some interesting things about Concavenator:

1) In talking with reporters, note to them that it is Conca- venator (hunter
of Cuena), not Concave-nator (the concave swimmer?!?)

2) Most complete Cretaceous allosauroid skeleton yet known.

3) Anatomically intermediate between Jurassic allosauroids and specialized
Cretaceous carcharodontosaurids and neovenatorids. Its phylogenetic position
suggests either outside Carcharodontosauridae + Neovenatoridae or as the
basalmost carcharodontosaurid.

4) "Quill nodes" on unlae would be considered quill nodes if found in a
maniraptoran, but somewhat more problematic (an extrapolation rather than an
interpolation) outside Coelurosauria. Sadly, no impression of integument
near arms.

5) On the other hand, lots of integument in the rest of the skeleton.
Highlights include preserved impressions of toe pads and crocodilian-like
rectangular scales on the ventral surface of at least the tail. The latter
are also known in Triceratops. Might these be a widely-distributed
archosaurian feature?

6) The dorsoventrally tall but anteroposteriorly short triangular crest is
odd, to say the least. Of question is whether other isolated tall-spined
theropod vertebrae (e.g. Beckelspinax) of Cretaceous Europe might be from
Concavenator or a close kin?

        6') If that material IS from a Concavenator-like theropod, than the
Crystal Palace Megalosaurus includes some Concavenator-like inspiration, and
thus this newest-reported theropod was first illustrated in part in the
1850s!

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 

> -----Original Message-----
> From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] 
> On Behalf Of Jocelyn Falconnet
> Sent: Wednesday, September 08, 2010 1:51 PM
> To: Dinosaur Mailing List; Ian Paulsen
> Subject: Concavenator corcovatus, a new humped 
> carcharodontosaurid from Las Hoyas
> 
> Neat !
> Thank you Ian !
> 
> :-D
> 
> Here is the appropriate reference and the abstract:
> 
> Ortega F., Escaso F. & Sanz J.L. 2010. A bizarre, humped 
> Carcharodontosauria (Theropoda) from the Lower Cretaceous of Spain.
> Nature 467: 203-206.
> 
> Carcharodontosaurs were the largest predatory dinosaurs, and 
> their early evolutionary history seems to be more intricate 
> than was previously thought. Until recently, 
> carcharodontosaurs were restricted to a group of large 
> theropods inhabiting the Late Cretaceous Gondwanan land 
> masses, but in the last few years Laurasian evidence has been 
> causing a reevaluation of their initial diversification. Here 
> we describe an almost complete and exquisitely preserved 
> skeleton of a medium-sized (roughly six metres long) theropod 
> from the Lower Cretaceous series (Barremian stage) 
> Konservat-Lagerstätte of Las Hoyas in Cuenca, Spain. 
> Cladistic analysis supports the idea that the new taxon 
> *Concavenator corcovatus* is a primitive member of 
> Carcharodontosauria, exhibiting two unusual features: 
> elongation of the neurapophyses of two presacral vertebrae 
> forming a pointed, hump-like structure and a series of small 
> bumps on the ulna. We think that these bumps are homologous 
> to quill knobs present on some modern birds; the knobs are 
> related to the insertion area of follicular ligaments that 
> anchor the roots of the flight feathers (remiges) to the arm. 
> We propose that *Concavenator*  has integumentary follicular 
> structures inserted on the ulna, as in modern birds. Because 
> scales do not have follicles, we consider the structures 
> anchored to the
> *Concavenator* arms to be non-scale skin appendages 
> homologous to the feathers of modern birds. If this is true, 
> then the phylogenetic bracket for the presence of non-scale 
> skin structures homologous to feathers in theropod dinosaurs 
> would be extended to the Neotetanurae, enlarging the scope 
> for explaining the origin of feathers in theropods.
> 
> --
> Jocelyn Falconnet
> 
> 2010/9/8 Ian Paulsen <birdbooker@zipcon.net>:
> > HI ALL:
> >  FYI:
> >
> > 
> http://news.yahoo.com/s/ap/20100908/ap_on_sc/us_sci_humpbacked_dinosau
> > 
> r;_ylt=AkTES2LpLeEnKiAIfkNSAdoPLBIF;_ylu=X3oDMTJybnNpMWVyBGFzc2V0A2FwL
> > 
> zIwMTAwOTA4L3VzX3NjaV9odW1wYmFja2VkX2Rpbm9zYXVyBGNwb3MDMQRwb3MDMQRzZWM
> > DeW5fdG9wX3N0b3J5BHNsawN3b3VsZHlvdWxpa2U-
> >
> > sincerely
> > --
> >
> > Ian Paulsen
> > Bainbridge Island, WA, USA
> > " Which just goes to show that a
> >  passion for books is extremely unhealthy."
> >  from Cornelia Funke's "Inkheart".