[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Progressive birdyness?



At 02:09 PM 5/9/97 -0600, LN Jeff wrote:
>
>     Can anyone tell be if dromeosaurs and troodontids showed a tendancy
>to get more birdlike with time?  Is _Velociraptor_ more birdlike the
>_Deinonychus_?  Are Late Cretaceous troodontids more birlike then earlier
>ones?  If so, it would be a rather puzzling trend considering birds
>evolved in the Jurassic.

Not really, as far as is known.  Early Cretaceous dromaeosaurids and
troodontids are not particularly less bird-like than Late K forms.  Okay,
Utahraptor and Deinonychus seem to be more bulky than Velociraptor, but this
may simply reflect their bigger size overall.

One of the few groups of coelurosaurs which becomes more "bird-like" through
the Cretaceous are ornithomimosaurs, and this only because they lose their
teeth by the Senonian.  (And, of course, losing their teeth makes them like
neornithine birds, not like classic Mesozoic birds!).

Thomas R. Holtz, Jr.
Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
Dept. of Geology              Email:th81@umail.umd.edu
University of Maryland        Phone:301-405-4084
College Park, MD  20742       Fax:  301-314-9661