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Re: Details on Adasaurus



Alessandro Marisa wrote-

> If I remember correctly Dinonychus is not a Dromaeosaurinae, but is a
> Velociraptorinae (with Velociraptor and Saurornitholestes).
Velociraptorinae
> and Dromaeosaurinae are easily distinguished in their teeth. The
serrations
> on the front of the Dromaeosaurinae teeth are about the same size as the
> serrations on the back of the same teeth. In Velociraptorinae, the
posterior
> serrations are much larger that the anterior one. And the premaxillary
teeth
> of the Dromaeosaurinae are all about the same size, whereas the second
teeth
> of this bone is the largest in Velociraptorina. Based on the Ostrom's
> Deinonychus osteology (1969) the teeth of Deinonychus have all the
charaters
> tipical of the Velociraptorinae Dromaeosauridae, Utahraptor have a teeth
> morphology much more similar to that of Dromaeosaurinae.

You're correct. What I said was from Barsbold's 1983 paper and I did not
mean to imply that Deinonychus is a dromaeosaurine.  My analysis places
Dromaeosaurus as the sister group to other dromaeosaurids studied, so all
the others (Achillobator, Deinonychus, Velociraptor, Unenlagia, Bambiraptor
and Sinornithosaurus) are in the Velociraptorinae. This may change as I add
more characters.  As for the dental characters, the comparative size of
premaxillary teeth actually supports Deinonychus being more basal to
Velociraptor and Sinornithosaurus, because, as Ostrom (1969) states "the
alveoli (of the premaxillary teeth) are subequal in size" (parentheses
mine).  Utahraptor appears to have the derived condition.  How do we know
that Dromaeosaurus doesn't though, only the last two alveoli are known!

Mickey Mortimer