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Re: New Papers of the Ya-Ya Sisterhood
Smith's (2007) phylogenetic analysis removed _Acrocanthosaurus_ and
_Neovenator_ from the Carcharodontosauridae and put them both in the
Allosauridae (sensu lato).
The following SVP meeting abstract, also from this year, puts them back:
Stephen Brusatte & Paul Sereno: Phylogeny of Allosauroidea (Dinosauria:
Theropoda): new analysis, comparisons, and sources of disagreement, p. 54A
Allosauroidea, a large-bodied clade of theropod dinosaurs ranging from the
Middle Jurassic to the Late Cretaceous, has been the subject of several
phylogenetic studies that have reached little consensus. We present a
comparative cladistic analysis that attempts to integrate data from previous
studies with new characters revealed by the description of several new
allosauroid taxa from Africa and South America and the redescription of
*Neovenator salerii* from the Early Cretaceous of England. First we review
twelve previous studies of allosauroid phylogeny and discuss areas of
topological disagreement. Second we compare our dataset to those of previous
studies and evaluate the degree of overlap using novel comparative metrics
that quantify shared character data. Our comparisons show that scoring
differences, character choice, and taxonomic sampling are all major sources
of incongruence. Importantly, numerous scoring differences highlight
currently conflicting observations that must be resolved. Then we evaluate
the status of the current understanding of allosauroid phylogeny and discuss
the importance of rigorous comparative techniques in studies of dinosaur
phylogeny. Finally we present our new analysis, based on 102 characters
scored in 10 ingroup taxa, which represents the most extensive analysis of
allosauroid phylogeny yet undertaken. The analysis strongly supports
positioning *Sinraptor* as the basal-most [sic] allosauroid, *Neovenator* as
the basal-most member of Carcharodontosauridae, and *Acrocanthosaurus* as a
derived member of Carcharodontosauridae rather than a close relative of
*Allosaurus*. This topology shows a strong overall match with the
stratigraphic record, and cladistic biogeographic analysis suggests that the
distribution of allosauroids is congruent with the breakup sequence of
Pangaea.