Left ectopterygoids of (A) Sinraptor dongi (image
modified from [16]), (B) Allosaurus fragilis
(image modified from [69]), (C) Acrocanthosaurus
atokensis (NCSM 14345), and (D) Giganotosaurus
carolinii (MUCPv-CH-1) in dorsal (top row) and lateral
(bottom row) views. Characters 81 and 82 appear to be dependent upon
first examination, as both Acrocanthosaurus and
Giganotosaurus share an ectopterygoid with a narrow
jugal ramus (82∶1) that is rotated dorsally (81∶1), in
contrast to the more robust jugal ramus (82∶0) that lies parallel
to the main body of the ectopterygoid (81∶0) in
Allosaurus and Sinraptor. However,
the presence of a dorsally rotated jugal ramus (81∶1) in
Carnotaurus (a basal theropod consistently
recovered outside of Allosauroidea [81]) coinciding with a
wide jugal ramus and narrow subtemporal fenestra (82∶0), suggests
that the states are independent. j, jugal contact;
jr, jugal ramus; pt, pterygoid contact;
stf, subtemporal fenestra.