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Re: Re: New Antarctic Theropod
>>From firstname.lastname@example.org Wed May 11 10:16:52 1994
> > I am curious about the crest on the skull of the new theropod found
> > in the antarctic (I forget the name given to it).
>I think that must be Monolophosaurus.
The new theropod is Cryolophosaurus ellioti, from the Early Jurassic of
> > I see that Dilophosaurus
> > also had a crested skull, and have read various theories on the
> > hadrosaur crests. Any comments or theories on these theropod skull
>They would have basically the same function - species-specific
>recognition and mate attraction.
>[It is pretty well established now that hadrosaur crests combine
>visual and acoustic recognition signals].
>Actually, many theropods have crests, it is just that they are
>usually *small*. For instance, Tyrannosaurus actually has crests,
>in the form of low horny ridges above the eyes.
And the nose, as well. Other tyrannosaurids have a slightly different
pattern, and one (Alioramus) had a series of little nose hornlets running
down its snout.
> And Allosaurus
>has its own, different, pattern of horny ridges.
In the case of Allosaurus, there are two prominent "horns" in front of the
eyes, and a pair of ridges along the top of the snout. These are best seen
in the Smithsonian's specimen.
FYI, the primary difference between the crest of Crylophosaurus and all
other theropods is that it is oriented perpendicular to the main axis of the
skull, not parallel.
>MY question about this beastie is: which group of theropods does
>it belong to? Is it related to Dilophosaurus, or Carnotaurus
>(another large-crested theropod), or to Tyrannosaurus, or what?
Last I heard, Currie and Hammer regarded Cryolophosaurus as close to the
Sinraptoridae (Yangchuanosaurus and Sinraptor), and thus not too far from
Allosaurus. I haven't seen the paper as published, yet, so they may have
changed their minds.
Thomas R. HOLTZ
Vertebrate Paleontologist, Dept. of Geology