Re: new dinosaurs

[Tim Williams <twilliams_alpha@hotmail.com>]

I wrote:

> I have not yet seen the JVP paper (though I would dearly love to), but the 
> cladogram in _Dinosauria II_ shows that _Appalachiosaurus_ and 
> _Dryptosaurus_ come up in different parts of the Tyrannosauroidea tree. The 
> "Alabama taxon" (= _Appalachiosaurus_) belongs on the 
> _Albertosaurus_-_Gorgosaurus_ line of the Tyrannosauridae, whereas 
> _Dryptosaurus_ is given as a basal tyrannosauroid. Any similarities between 
> the two are presumably symplesiomorphic.

Scratch that.  According to the JVP paper, both _Dryptosaurus_ and 
_Appalachosaurus_ are basal tyrannosauroids - though certainly distinct.

THOMAS D. CARR, THOMAS E. WILLIAMSON, AND DAVID R. SCHWIMMER (2005).  A new 
genus and species of tyrannosauroid from the Late Cretaceous (Middle 
Campanian) Demopolis Formation of Alabama.  Journal of Vertebrate 
Paleontology 25(1): 119-143

ABSTRACT: The discovery of a new genus and species of tyrannosauroid from 
the Demopolis Formation (middle Campanian) of Alabama increases the known 
diversity of the clade, although it does not elucidate the place of initial 
dispersal. This subadult tyrannosauroid is the most complete non-avian 
theropod collected and described from the Cretaceous of eastern North 
America. In contrast to tyrannosaurids, the new taxon possesses several 
plesiomorphic characters, including lacrimals that lack a distinct peaked 
cornual process, and a dorsoventrally shallow horizontal ramus of the 
maxilla. Autapomorphies include a wide jugal process of the ectopterygoid, a 
caudal pneumatic foramen of the palatine that pierces the rostral half of 
the vomeropterygoid process of the bone, an articular surface for the 
lacrimal on the palatine that is distally positioned on the dorsolateral 
process, and pedal unguals that have a distinct proximodorsal lip over the 
articular surface. Cladistic analysis indicates the new taxon is a basal 
tyrannosauroid and its presence in eastern North America suggests that the 
recent common ancestor of Tyrannosauridae probably evolved following the 
transgression of the Western Interior Seaway. Cladistic analysis indicates 
that Dryptosaurus aquilunguis is also a basal tyrannosauroid but is less 
derived than the new genus.