Re: read and learn

["Thomas R. Holtz, Jr." <th81@umail.umd.edu>]

At 09:48 AM 4/4/98, Dave wrote:

>I am less confident about exactly what strategy tyrannosaurs used to kill.
>Tom Holtz and others have suggested that they fall into the pursuit and
>bite category, typified by large canids.  But it is difficult for me to
>envision a tyrannosaur-ceratopsian chase through forest.

Please note: not all tyrannosaurids (for that matter, not all Tyrannosaurus
rex individuals) lived in forested regions.  Tyrannosaurids are spread from
arid to semi-open to forested regions.

>I find it more
>plausible that large theropods used a Komodo dragon type strategy, waiting
>along animal trails and lunging out at their prey as it passed by.  They
>slashed horrific wounds, then followed their prey until it succumbed.

"Munched" or "chomped", yes.  "Slashed", no.  Would work for almost any
group of large theropod *except* tyrannosaurids, which have very un-slashing
jaws.  See DinoFest & SVP this year.

>I
>believe the reason tyrannosaurs are so gracile is that it does little good
>to slash a ceratopsian and then track down its corpse if someone else gets
>to it first!  This is exactly the problem Komodo dragons face.  Having
>cursorial adaptations allows you to move quickly at greater energy
>efficiency, thus reaching your kill before the other tyrannosaurs can.  I
>believe this is what drove selection for cursorial adapations in tyrannosaurs.

Except that the cursorial adaptations tyrannosaurs have are shared with the
closest relatives: ornithomimosaurs and troodontids...

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