Giant temnospondyl amphibians from the Early to Middle Triassic Narrabeen Group of the Sydney Basin, New South Wales, Australia

Material of giant temnospondyl amphibians is described from two localities in the Early to Middle Triassic Narrabeen Group of the Sydney Basin, Australia. The capitosaurid Bulgosuchus gargantua gen. et. sp. nov. from the Bulgo Sandstone (Scythian) at Longreef, represented by an incomplete mandible and a femur, is the largest known Early Triassic temnospondyl and the earliest occurrence of a temnospondyl in the Sydney Basin Triassic. B. gargantua is phenetically most similar to Paracyclotosaurus and to ‘P’. gunganj, but also shows affinities with Eryosuchus and Middle Triassic species of ‘Parotosuchus’. An anterior portion of a large mandible from the Terrigal Formation (late Scythian-early Anisian) at Bouddi is also described and tentatively referred to the Capitosauridae, but is generically indeterminate. The morphology of the post-glenoid area in members of the Capitosauridae is described, and derived characters of the capitosaurid mandible are provided.