''Hovasaurus'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus of diapsid

reptile Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephalians ( ...

belonging to the order Eosuchia. It lived in what is now Madagascar during the Late Permian and Early Triassic, being a survivor of the Permian–Triassic extinction event and the paleontologically youngest member of the Tangasauridae. Fossils have been found in the Permian Lower and Triassic

Middle Sakamena Formation Middle or The Middle may refer to: * Centre (geometry), the point equally distant from the outer limits. Places * Middle (sheading), a subdivision of the Isle of Man * Middle Bay (disambiguation) * Middle Brook (disambiguation) * Middle Creek ...

s of the

Sakamena Group Sakamena is a village near Betroka in the region of Anosy in Madagascar. Sakamena is also the name of a Permian sedimentary geological formation that has yielded many vertebrate fossil, including Triadobatrachus (the first lissamphibian), Claudio ...

, where it is amongst the commonest fossils. Its morphology suggests an aquatic ecology.

Description

''Hovasaurus'' resembled a slender lizard, two thirds of total length was taken up by its long tail. It had snout-vent length up to long, with long tail. It was well adapted to an aquatic life, with the tail being laterally flattened like that of a

sea snake Sea snakes, or coral reef snakes, are elapid snakes that inhabit marine environments for most or all of their lives. They belong to two subfamilies, Hydrophiinae and Laticaudinae. Hydrophiinae also includes Australasian terrestrial snakes, wher ...

. Some stones have been found in the abdomen of fossil ''Hovasaurus'', indicating the creatures swallowed these for ballast, preventing them from floating to the surface when hunting fish.

Paleoenvironment

The Lower Sakamamena Formation was deposited in a wetland environment situated within a North-South orientated rift valley, perhaps similar to

Lake Tanganyika Lake Tanganyika () is an African Great Lake. It is the second-oldest freshwater lake in the world, the second-largest by volume, and the second-deepest, in all cases after Lake Baikal in Siberia. It is the world's longest freshwater lake. ...

. The climate at the time of deposition was temperate, warm, and humid, with seasonal rainfall and possible monsoons Flora from the formation includes the equisetalean '' Schizoneura'', '' Glossopteris'', and seed fern ''

Lepidopteris ''Lepidopteris'' ("scaly fern") is a form genus for leaves of Late Permian to Late Triassic Period Pteridospermatophyta, or seed ferns, which lived from around 260 to 200 million years ago in what is now Australia, Antarctica, India, South Amer ...

.'' Other vertebrates known from the Lower Sakamena Formation include the

palaeoniscoid Palaeoniscidae is an extinct family of ray-finned fishes (Actinopterygii) ascribed to the order Palaeonisciformes. The family includes the genus '' Palaeoniscum'' and potentially other Palaeozoic and Mesozoic early actinopterygian genera. The n ...

fish '' Atherstonia'', the procolophonid parareptile ''

Barasaurus ''Barasaurus'' is an extinct genus of owenettid procolophonoid parareptile known from the late Late Permian and early Early Triassic of Madagascar. It contains a single species, ''Barasaurus besairiei''. Discovery ''Barasaurus besairiei'', the t ...

'', the gliding

weigeltisaurid Weigeltisauridae is a family of gliding neodiapsid reptiles that lived during the Late Permian, between 258 and 252 million years ago. Fossils of weigeltisaurids have been found in Madagascar, Germany, Great Britain, and Russia. A possible weigelt ...

reptile '' Coelurosauravus'', neodiapsids ''

Claudiosaurus ''Claudiosaurus'' (''claudus'' is Latin for 'lameness' and ''saurus'' means 'lizard') is an extinct genus of diapsid reptiles from the Permian Sakamena Formation of the Morondava Basin, Madagascar. The pattern of the vertebrate, girle, and limbs ...

, Thadeosaurus'', and '' Acerodontosaurus'', fragments of

rhinesuchid Rhinesuchidae is a family of tetrapods that lived primarily in the Permian period. They belonged to the broad group Temnospondyli, a successful and diverse collection of semiaquatic tetrapods which modern amphibians are probably descended from. ...

temnospondyls, an indeteriminate theriodont therapsid and the dicynodont ''

Oudenodon ''Oudenodon'' is an extinct genus of dicynodont. It was common throughout southern Africa during the Late Permian. Several species of ''Oudenodon'' are known. Both ''O. bainii'', the type species, and ''O. grandis'' are known from South Africa ...

.''Smith, R. M. H. 2000. Sedimentology and taphonomy of Late Permian vertebrate fossil localities in Southwestern Madagascar. Paleontologia Africana 36:25–41

Description

Paleoenvironment

References

Further reading