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

Re: Island-dwelling dinosaurs (was Re: Gargantuavis neck vertebra)

Am 15.06.2012 um 07:01 schrieb Tim Williams:

 David Marjanovic <david.marjanovic@gmx.at> wrote:

>> The _Gargantuavis_ type material and the new neck vertebra come
>> from the Ibero-Armorican island. Cretaceous birds of Europe may
>> have been especially prone to secondary flightlessness.
> Despite the contemporary presence of dromaeosaurids and
> abelisaurids of usual sizes? (Buffetaut pointed this out as a
> mystery in his talk.)

 No mystery at all.

I wasn't talking about the size but about the flightlessness. Why would a bird become flightless in the presence of terrestrial predators? The ratites, gastornithids, dromornithids and others now seem to have become flightless in the Paleocene, which was almost devoid of large terrestrial predators. *Gargantuavis* may have become flightless before it met the predators, but where?

That said, of course, there's *Patagopteryx*, which not only seems to have done that, but stayed small in the process. That's a mystery -- and it's a mystery that's independent of *Gargantuavis*, as the latter seems to be a quite crownward ornithurine according to Buffetaut.