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Stephan Pickering wrote-
I do not accept "Carnosauria" as a valid taxon -- as yet. There
are a plethora of taxa whose affinities are in flux, primarily because of
convergences in a number of character traits. For example, I would position
Coelophysis and its allies outside of Ceratosauria, with Ceratosaurus
and abelisaurs as sister taxa to Tetanurae. I would, also, place
Megalosauridae within Avetheropoda (Megalosaurus = Torvosaurus,
Eustreptospondylus, Metriacanthosaurus, Poecilopleuron, Gasosaurus?,
Piatnitzkysaurus?), with the "spinosaurs" as a closely related group.
Although it would create enormous taxonomic headaches, I believe it possible
Allosaurus and Streptospondylus and Neovenator could be
synonymized.
Technically, your Megalosauridae Spinosauridae +
Allosauridae clade would be Carnosauria (everything closer to Allosaurus than to
birds). I like the paraphyletic Ceratosauria. I don't see how you
could justify synonymizing Streptospondylus with Allosaurus, as Allain did a
good job of showing it was a spinosauroid closely related to
Eustreptospondylus. Synonymizing Allosaurus and Neovenator much makes
virtually all allosaurids Allosaurus, as Neovenator is thought to be closer
to carcharodontosaurines(-ids) than Allosaurus. I don't find the thought
of Allosaurus saharicus, A. atokensis or A. carolini very
appealing.
Mickey Mortimer
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