Genusaurus Temporal range: Early Cretaceous, 106 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Dinosauria
Clade:	Saurischia
Clade:	Theropoda
Superfamily:	†Abelisauroidea
Family:	†Abelisauridae
Genus:	†Genusaurus Accarie et al., 1995
Species:	†G. sisteronis
Binomial name
†Genusaurus sisteronis Accarie et al., 1995

Genusaurus (/ˌdʒɛnjʊˈsɔːrəs/ JEN-yuu-SOR-əs;^[1] meaning "knee lizard") is a genus of abelisaurid theropod from the Early Cretaceous. Its fossils were found in France. Genusaurus is believed to have lived during the Albian stage, around 112-100 million years ago.^[2][3]

Description

Genusaurus possesses several distinguishing traits. The dorsal vertebrae are elongated. The elements of the pelvis are strongly fused. The thighbone shows a low bone plateau below the major trochanter; to the front an accessory trochanter is present. The epicondyle of the inner femoral condyle is well-developed. The cnemial crest strongly extends to the front and is curved upwards. The fibula has a distinctive boss serving as an attachment for the Musculus iliofibularis. The upper inner side of the fibula is strongly hollowed out.^[4]

Discovery and naming

The type species, Genusaurus sisteronis, is the only named species. It is based on a partial skeleton found in 1984-1986 in the Albian Bevons Beds, holotype MNHN Bev.1. The holotype contains seven partial dorsal vertebrae, a piece of a sacral, a piece of an ilium, the top of a pubic bone, a thighbone, the top of a shinbone, the top of a fibula and a metatarsal. It was named and described by Hugues Accarie, Bernard Beaudoin, Jean Dejax, Gérard Friès, Jean-Guy Michard and Philippe Taquet in 1995.^[4] The genus name is derived from the Latin word genu (knee) and refers to the cnemial crest in front of the proximal end of the tibia.^[4] The specific name refers to Sisteron, the town near which the specimen was found.^[4]

Classification

Accarie et al. assigned Genusaurus to the ceratosaur group of theropods, more precisely to the Coelophysoidea.^[4] A 2008 cladistic analysis by Carrano and Sampson placed Genusaurus in the Noasauridae along with Laevisuchus, Masiakasaurus, Noasaurus, and Velocisaurus; in turn, noasaurids are part of the Abelisauroidea group, which is part of the ceratosaur group.^[3] Subsequent phylogenetic analyses found Genusaurus to be either a member of the Noasauridae or Abelisauridae.^[8][9][10] In 2025, Eric Buffetaut reexamined the holotype and suggested that it should be placed into Furileusauria.^[11]

See also

• Timeline of ceratosaur research

References

External links

• "Our Exhibitions: Genusaurus sisteronis" (in French) at the Réserve Naturelle Géologique de Haute-Provence, France.