Dromaeos, Deinonychosaurs, and Avialae (was Re: Megaraptor)

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

At 08:30 PM 11/27/97 -0600, you wrote:
>Quoth Thomas R. Holtz, Jr.:
>>Having seen photos & drawings of Megaraptor, I can say that it is very
>>similar to dromaeosaurids if it isn't a true dromaeosaur.  Of course, there
>>is another big avialian in the same sediments, for which we don't have
>>overlapping material, so it may be that Megaraptor will lose its name in
>>time...
>        Is this to imply that dromaeosaurs are "avialians".

Nope.

>What's an
>"avialian"?

See below.

>Do big ones have sickle claws too?

Well, cassowaries and seriamas...

>Is this like an avialan?
>Aren't those birds?

Avialae = modern birds and all taxa closer to modern birds than to Deinonychus.

For the record, Deinonychosauria = Deinonychus and all taxa closer to it
than to birds  

and

Dromaeosauridae = all descedants of the most recent common ancestor of
Dromaeosaurus and Velociraptor.

>What's my name?

I don't do mammal taxonomy...

>Am I missing some important piece of
>information here. I am very confused. I don't even know what day it is.
>Excuse me, I have to go calculate the jadeite+quartz/anorthite phase
boundary...
>

Ugh!

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