Re: Tyrannotitan, new carcharodontosaurid from Argentina

[David Marjanovic <david.marjanovic@gmx.at>]

> I take it this is not the same as Currie and Coria's long-awaited bonebed 
> carch?

No.

*Tyrannotitan* has an interesting autapomorphy: bilobate denticles on the 
mesial carinae.

108 characters, 15 taxa (data matrix in supplementary information):
--+--+--*Ceratosaurus*
 |  `--+--*Carnotaurus*
 |     `--+--*Abelisaurus* (not a carch)
 |        `--*Majungatholus*
 `--+--+--*Tyrannosaurus*
    |  `--+--Dromaeosauridae
    |     `--Oviraptoridae
    `--+--*Monolophosaurus*
       `--+--*Sinraptor*
          `--+--+--*Acrocanthosaurus*
             |  `--*Allosaurus*
             `--+--*Tyrannotitan*
                `--+--*Carcharodontosaurus*
                   `--*Giganotosaurus*

*Acrocanthosaurus* and *Allosaurus* have 3 unambiguous synapomorphies, and 9 
additional steps are required to make *Ac.* a carch. Too bad *Neovenator* 
isn't even mentioned.

"*Spinosaurus* B" and *Sigilmassasaurus* are not synonyms of 
*Carcharodontosaurus*, but they closely resemble each other (or at least one 
cervical of each does).

"After the strong decline of carcharodontosaurids and the virtual extinction 
of spinosaurids at the end of the Cenomanian, theropod assemblages from 
South America, Madagascar and India consisted mainly of comparatively 
smaller abelisauroids, and secondarily of a wide array of tetanurans (e.g., 
*Megaraptor*, coelurosaurians)."