Hovasaurus

Abstract: Recently discovered reptile specimens from the "Eotriassic" deposits of Madagascar (Lower Triassic) are reported, adding valuable information to our knowledge of Malagasy faunas and providing additional data on tetrapod survivorship across the Permian–Triassic (P–T) boundary. Four specimens are attributable to the terrestrial procolophonoid Barasaurus besairiei Piveteau 1955, whereas the remainder are referable to the aquatic younginiform family Tangasauridae, including some individuals identifiable as Hovasaurus boulei Piveteau 1926. These specimens represent the geologically youngest tangasaurid and Barasaurus specimens to be described from Madagascar and suggest that these small reptiles passed unaffected through the end Permian mass extinction event, when ~78% of amniote families disappeared.

Abstract: The mould of a single specimen of a primitive diapsid reptile has recently been discovered in beds of Lower Triassic age near Mombasa, Kenya. The specimen, designated as the type of a new species and genus, Kenyasaurus mariakaniensis, lacks the skull and much of the pectoral girdle and forelimb, but is otherwise well preserved. It resembles the aquatic eosuchians Tangasaurus and Hovasaurus (from Tanzania and the Malagasy Republic) in size and general body proportions, but the tail is not specialized as a swimming organ as it is in the previously described genera. The fifth distal tarsal is not a separate element, but the fifth metatarsal is not hooked. There is a well developed sternum. The Kenyan specimen furnishes detailed information about the postcranial skeleton of what may be a hitherto unrepresented lineage of eosuchian reptiles.

Abstract: THE COUNCIL’S RESEARCH COMMITTEE, UNIVERSITY OF THE WITWATERSRAND; NATIONAL RESEARCH FOUNDATION (NRF); The Open Research Programme of the Foundation for Research Development

Abstract: Tangasaurid eosuchians are represented by hundreds of specimens from the Permo-Triassic strata of Madagascar and Africa. The confusion surrounding the identification and anatomy of these reptiles is resolved by comparative anatomy and relative measurements, and three genera, Thadeosaurus, Tangasaurus and Hovasaurus, are described. Extensive growth series present a unique opportunity to study differences in growth strategies in two closely related Permian genera, one that was terrestrial (Thadeosaurus) and the other aquatic (Hovasaurus). The vertebrae of Youngina have a derived character state that indicates close relationship with the tangasaurids. A new genus and species of eosuchian, Acerosodontosaurus piveteaui, has a specialized feature in the carpus that is found in the Tangasauridae. The relationships between tangasaurids and other eosuchians are considered.