''Lacertulus'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia al ...

-like reptile, possibly a

lepidosauromorph Lepidosauromorpha (in PhyloCode known as ''Pan-Lepidosauria'') is a group of reptiles comprising all diapsids closer to lizards than to archosaurs (which include crocodiles and birds). The only living sub-group is the Lepidosauria, which contain ...

, from the

Karoo Supergroup The Karoo Supergroup is the most widespread stratigraphic unit in Africa south of the Kalahari Desert. The supergroup consists of a sequence of units, mostly of nonmarine origin, deposited between the Late Carboniferous and Early Jurassic, a pe ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring count ...

. It contains a single species, ''Lacertulus bipes'', which is based on a small articulated skeleton stored in the

Transvaal Museum The Ditsong National Museum of Natural History, formerly the Transvaal Museum, is a natural history museum situated in Pretoria, South Africa. It is located on Paul Kruger Street, between Visagie and Minnaar Streets, opposite the Pretoria City Hal ...

Pretoria Pretoria () is South Africa's administrative capital, serving as the seat of the executive branch of government, and as the host to all foreign embassies to South Africa. Pretoria straddles the Apies River and extends eastward into the foot ...

. The origin and locality of the specimen is unknown, though it is embedded in a greenish-gray

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, ...

similar to some sediments from the

Late Permian Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effect, ...

''Daptocephalus'' Assemblage Zone. The skeleton is mostly complete apart from the

distal Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

part of the tail, but erosion and improper preparation has damaged the skull and parts of the torso. Though originally described as a

lepidosaur The Lepidosauria (, from Greek meaning ''scaled lizards'') is a subclass or superorder of reptiles, containing the orders Squamata and Rhynchocephalia. Squamata includes snakes, lizards, and amphisbaenia, amphisbaenians. Squamata contains over 9, ...

, poor preservation has lent doubt to this conclusion. ''Lacertulus'' is notable for its small size (around 5 cm or 2.0 inches in snout-vent length) and proportionally small forelimbs relative to the large and well-ossified hindlimbs. The short

humerus The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

in particular suggests that it was capable of some degree of bipedal locomotion when escaping predators, by comparison to modern facultatively bipedal lizards such as ''

Crotaphytus ''Crotaphytus'' is a genus of lizards commonly known as collared lizards. They are a genus of small to medium-sized predators indigenous to the American southwest, Baja peninsula, and Mexico. They can be as small as 8" or as long as 14″ (20-3 ...

'' (collared lizards).

References

Fossils of South Africa Fossil taxa described in 1982 Prehistoric reptile genera {{paleo-reptile-stub