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Re: Tetanurae

Jamie Stearns wrote-

As for the relationship between Ceratosaurus, coelophysoids, abelisauroids, and tetanurans, I would say that while coelophysoids are probably a paraphyletic group leading up to (neo)Ceratosauria/Tetanurae, abelisauroids still can be grouped with Ceratosaurus, as osteoderms were found in both Ceratosaurus and Carnotaurus, but not, to my knowledge, in any tetanuran for which skin impressions are known.

There are no osteoderms known for Carnotaurus. The skin impressions do include low conical protuberances, but there's no evidence these contained bone. I believe similar protuberances are known for other large dinosaurs such as hadrosaurs and ceratopsids, but lack any bony component.

As an aside, I don't agree with Sereno's revision of Tetanurae's definition, adding Carnotaurus. As I wrote previously-
The addition of Carnotaurus as an external specifier by Sereno (2005) seems counter-productive. Tetanurae was designed as a stem away from Ceratosaurus, and abelisaurids were not explicitly discussed (having been named only a year prior). In fact, technically, Indosaurus and Indosuchus were classified as tetanurines by Gauthier (1986), since he lists them as carnosaurs. If abelisaurids are megalosauroids (as in Paul, 1988), it shouldn't stop megalosauroids from being tetanurines.

Mickey Mortimer