Capsule summary: the Revueltosaurus case

Fri Feb 29 18:59:10 GMT 2008


In 1989, Hunt named Revueltosaurus callenderi based on isolated teeth, and tentatively classified it as an ornithischian dinosaur. Hunt and Lucas (1994:234-235) subsequently redescribed this animal, referring it firmly to Ornithischia. Hunt and Lucas (1989:91) and Hunt (2001:141-142) mentioned a crocodilian (an early crocodile relative) from the type locality of Revueltosaurus, but did not describe it, name it or refer it to any existing taxon. This specimen was described in Hunt's (1994) unpublished Ph.D dissertation, but considered distinct from Revueltosaurus.

Heckert (2002) again redescribed Revueltosaurus, affirming its ornithischian identity. Between 1994 and 2004, Lucas and his colleagues published several more papers referring to Revueltosaurus as an ornithischian (e.g. Heckert and Lucas 1998, Hunt et al. 1998:519, Heckert 2001:283).

In March 2004, Bill Parker discovered new skeletons of Revueltosaurus callenderi -- much more complete material than the holotype. This discovery showed that Revueltosaurus was not a dinosaur -- a fact first alluded to in a published SVP abstract (Stocker et al. 2004). With further work, Parker and colleagues determined that Revueltosaurus was a basal crocodilian. In late 2004, Parker and his colleagues prepared a manucript on this find: it was submitted to the Proceedings of the Royal Society in October, resubmitted after review on December 2, and accepted on 10 December 2004.

Parker did not conceal his findings from other palaeontologists, and so in late 2004, Heckert (2004) published a revised version of his dissertation as a NMMNHS Bulletin and noted on p. 21 a personal communication from Parker and colleagues that Revueltosaurus was a non-dinosaurian archosaur. If Hunt and colleagues had at this point discovered independently that Revueltosaurus was not a dinosaur, it would seem logical that their close colleague Heckert would have cited a personal communication from them rather than Parker. In March 2005, Parker gave a talk on his findings at a conference in St. George, Utah (Parker et al. 2005a:19). Hunt and Lucas were in the audience, and afterwards told Parker that they agreed with his reassessment but did not otherwise comment.

In April of that year, Hunt and Lucas (2005:53) published an abstract which stated that, through preparation of the skeleton first mentioned by Hunt and Lucas in 1989, they had determined that Revueltosaurus was a crocodilian rather than a dinosaur. They did not cite Parker's reassessment.

In May 2005, Parker et al. (2005b) was published in the Proceedings of the Royal Society.

In autumn 2005, Hunt et al. (2005) published a paper in an NMMNHS Bulletin volume edited by Heckert and Lucas, describing the postcranial skeleton of Revueltosaurus. Although they cited Parker et al. (2005a, 2005b), they used their own abstract as the primary authority for this discovery rather than Parker et al.'s abstract (which has priority) or Parker et al's Proceedings paper (which redescribed the material more comprehensively); and the absence of citation of Parker's work in the Discussion and Conclusions implied that their discovery was independent of Parker's.

(Note. While preparing their 2005 manuscript in 2004, Parker and his colleagues saw the New Mexico crocodilian first mentioned by Hunt and Lucas (1989), and recognised it as a specimen of Revueltosaurus. They refrained from including it in their 2005 paper out of courtesy to Hunt, as it had been mentioned in his dissertation.)