Taxonomy of the archosaur Ornithosuchus: reassessing Ornithosuchus woodwardi Newton, 1894 and Dasygnathoides longidens (Huxley, 1877)

VON BACZKO, M.B.; EZCURRA, M.D.

EARTH AND ENVIRONMENTAL SCIENCE TRANSACTIONS OF THE ROYAL SOCIETY OF EDINBURGH

ROYAL SOC EDINBURGH

Lugar: Edinburgo; Año: 2016 vol. 106 p. 199 - 206

1755-6910

The pseudosuchian archosaur Ornithosuchus, from the Lossiemouth Sandstone Formation (Late Triassic), Scotland, was the first ornithosuchid to be discovered and the only one recorded in the northern hemisphere. The fossil record of ?Ornithosuchus longidens? is mainly based on natural moulds and, in a few cases, three-dimensional bony elements, complicating the interpretation of its anatomy. The taxonomy of this species has changed several times since the late 1800s and here we revisit its current status. The synonymy of ?Dasygnathoides longidens? and Ornithosuchus woodwardi proposed by Walker (1964) is rejected based on new interpretations of the hypodigm of ?Dasygnathoides longidens?. This last species is here considered as a nomen dubium because it lacks diagnostic features and cannot be identified beyond Pseudosuchia. As a result, Ornithosuchus woodwardi is resurrected as a valid species and its diagnosis is emended. The body size range of Ornithosuchus woodwardi is reduced to about a half, because EM 1, previously considered the largest specimen of the genus, can no longer be referred to it. ?Dasygnathoides longidens? cannot be assigned to any of the known archosauriforms from the Lossiemouth Sandstone Formation, but it still represents the largest predator currently known for its fauna.