True, but that assumes that the "fighting dinosaurs" preserves a one-on-one
predation attempt, which I personally doubt (actually, it may not be a predation attempt
at all - consider that the Velociraptor appears to have been in the process of being
mangled badly). Incidentally, the 9kg mass for the azhdarchid in the new paper is
probably too low by a fair margin (9kg is about the mass of a large albatross). In any
case, we cannot absolutely rule out predation, but it would still seem that scavenging
would be the preferred hypothesis in this case.
This discussion/debate brings up an interesting question: what evidence should
we, as paleontologists, require before tentatively accepting a scavenging
hypothesis for a given preserved feeding event? And conversely, what evidence
should be required to tentatively accept a predation hypothesis?
--Mike Habib
On Mar 4, 2012, at 12:54 AM, Tim Williams wrote:
Mickey Mortimer<mickey_mortimer111@msn.com> wrote:
Scavenging's certainly possible, but since the closely related Deinonychus is
generally accepted as predating Tenontosaurus (which is about as heavy
compared to Deinonychus as Quetzelcoatlus is compared to Velociraptor), I don't
see how we can favor one hypothesis over another. Sure I'm assuming
that the Velociraptor was found singly, but if Roach and Brinkman (2007) are
correct that Deinonychus did not live in packs but merely aggregated to kill,
then a lone dromaeosaurid with parts of a large animal in its belly is just
what we'd expect.
There's also the famous "fighting dinosaurs": _Velociraptor_ preserved
in combat with _Protoceratops_. The _Velociraptor_ (an adult) is
estimated to have have weighed around 24 kg, the _Protoceratops_ at
least that much.
For the Hone&c study, the _Velociraptor_ was a sub-adult estimated to
have tipped the scales at 13 kg. The pterosaur is estimated to have
weighed at least 9 kg. So IMHO the contest between _Velociraptor_ and
pterosaur would be less daunting than _Velociraptor_ vs
_Protoceratops_. Also, pterosaurs (even azhdarchids) were less adept
on the ground than velociraptorines. Would it really have been
prohibitively difficult for a _Velociraptor_ to attack an azhdarchid
of comparable (or even lesser) body mass? Even if the pterosaur
weighed substantially more than the _Velociraptor_, predation still
seems to be well within the realm of possibility.
Cheers
Tim
Michael Habib
Assistant Professor of Biology
Chatham University
Woodland Road, Pittsburgh PA 15232
Buhl Hall, Room 226A
mhabib@chatham.edu
(443) 280-0181
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