Article: A late upper Triassic sphenosuchid crocodilian from Wales
Publication: Palaeontology
Volume:
27
Part:
1
Publication Date:
January
1984
Page(s):
131
–
157
Author(s):
P. J. Crush
Abstract
The fossil material of a 760 mm long crocodilian, Terrestrisuchus gracilis gen. et sp. nov., from a late upper Triassic fissure filling in the Carboniferous limestone of the old Pant-y-ffynon quarry near Cowbridge, Glamorgan, is described. The quadratojugal is parallel sided and the squamosal lacks a descending process. A hard secondary palate is formed by the maxillae and premaxillae. A fenestra pseudorotundum is present but the pterygoids were not sutured to the braincase. The Eustachian tubes were ramified. A prearticular is present. The teeth are recurved, flattened, and bear serrations. The ischium projects posteriorly and the pubis, bearing an obturator foramen, borders the open acetabulum. The postero-ventrally extended coracoid joins the ossified sternum. The carpals and tarsals are crocodilian. The fifth metatarsal is reduced but bears two phalanges. The dorsal vertebrae are primitive. A paired row of leaf-shaped dorsal scutes were present. The earliest crocodiles are placed in three suborders—Protosuchia, Sphenosuchia, and Triassolestia. The genus Pedeticosaurus is included in the Protosuchia which were ancestral to the Mesosuchia. Dibothrosuchus, Hesperosuchus, Hemiprotosuchus, Pseudohesperosuchus, and Sphenosuchus form part of the Sphenosuchia. Saltoposuchus and Terrestrisuchus belong in a new family Saltoposuchidae. Triassolestes and Hallopus are included in their own suborders. The Hallopoda, Sphenosuchia, and Triassolestia have no known descendants.