Ornithosuchus longidens ( Huxley, 1877 )

Nesbitt, Sterling J., 2011, The Early Evolution Of Archosaurs: Relationships And The Origin Of Major Clades, Bulletin of the American Museum of Natural History 2011 (352), pp. 1-292 : 22

Ornithosuchus longidens ( Huxley, 1877) , sensu Walker, 1964

AGE:?Late Carnian, Late Triassic ( Lucas and Heckert, 1996).

OCCURRENCE: Lossiemouth Sandstone Formation, various sandstone quarries in the Elgin area, Scotland (see Walker, 1964, for details).

HOLOTYPE: See Walker, 1961, 1964.

REFERRED MATERIAL: See Walker, 1964.

REMARKS: Ornithosuchus is one of the few archosaurs from the Late Triassic of Scotland known from both natural molds and preserved remains. The genus-level taxon has a complicated taxonomic history given the poor preservation of the specimens. Walker (1964) reviewed all species of Ornithosuchus and concluded that all the material from the Elgin area represents one species-level taxon, Ornithosuchus longidens . Walker’s concept of Ornithosuchus was followed by all subsequent workers. Sereno (1991a) listed five autapomorphies of Ornithosuchus that are accepted here.

The relationships of Ornithosuchus are as complicated as its taxonomy history. Since the initial description, Ornithosuchus was considered an archosaur (in the contemporary usage) with possible affinities with dinosaurs, phytosaurs, and aetosaurs ( Newton, 1894; Boulenger, 1903; Huene, 1914; Walker, 1964). In a modern cladistic framework, Ornithosuchus (5 Ornithosuchidae ) was first found as one of the most basal avian-line archosaur clades ( Gauthier, 1986; Benton and Clark, 1988), which was subsequently used as a basis to name the avian-line archosaur stem as Ornithosuchia ( Gauthier and Padian, 1985). More recent analyses placed Ornithosuchus closer to crocodylians than to phytosaurs ( Parrish, 1993; Benton, 1999), as the sister taxon of the Suchia ( Sereno, 1991a), or within Suchia ( Juul, 1994; Irmis et al., 2007a).

KEY REFERENCES: Huxley, 1877; Walker,

1964; Sereno, 1991a.