The taxonomy of the species referred to Allosaurus has been a contentious issue, assummarised by Paul (1988, 2010) and Chure (2000). Bakker (2000) and Paul (2010)claimed that Allosaurus fragilis (based on USNM 4734) is distinct from otherspecimens (DINO 2560, AMNH 666, etc.) by the proportions of its skull. However,Chure (2000) demonstrated that the supposed shortness of the skull of USNM 4734was based on an erroneous reconstruction of the skull by Gilmore (1920).
e are writing to support the petition (Case 3506) of Paul & Carpenter to conserve usage of Allosaurus fragilis Marsh, 1877 as the type species for genus Allosaurus by designating USNM 4734 as the neotype for Allosaurus fragilis Marsh, 1877. We support this conservation because of the taxon’s widely accepted usage by palaeontologists and its entrenched familiarity among the general public.
Here are several points of Case 3506 that need clarification:1. Hypsirophus discurus Cope, 1878 (mis-spelled as Hypsirophis discursis in BZN67: 54) is a stegosaur and not an allosaur (Maidment et al., 2008). The type specimen,AMNH 5731, actually consists of a dorsal vertebra, two caudal neural arches, andtwo caudal centra (Galton, 2010).2.
As the state paleontologist of Utah, I heartily support the proposal to make USNM4734 the neotype of Allosaurus. Allosaurus has been the Official State Fossil of Utahfor many years based primarily on the 54+ specimens of Allosaurus fragilis from ourCleveland/Lloyd Quarry (a national historic landmark) with many skeletons exhibitedacross the globe. No large theropod dinosaur is as well documented as Allosaurusand to risk losing this name would only serve to confuse and complicate our scienceamong the people of the world.