''Leyesaurus'' 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

massospondylid Massospondylidae is a family of early massopod dinosaurs that existed in Asia, Africa, North America, South America and AntarcticaHellert, Spencer M. "A New Basal Sauropodomorph from The Early Jurassic Hanson Formation of Antarctica." Geological ...

sauropodomorph dinosaur known from the San Juan Province, northwestern Argentina.

Description

''Leyesaurus'' is known from the holotype PVSJ 706, a nearly complete skull with articulated mandible and some

postcrania Postcrania (postcranium, adjective: postcranial) in zoology and vertebrate paleontology is all or part of the skeleton apart from the skull. Frequently, fossil remains, e.g. of dinosaurs or other extinct tetrapods, consist of partial or isolated sk ...

l remains ( vertebral column,

scapular The scapular (from Latin ''wikt:scapula#Latin, scapulae'', "shoulders") is a Western Christianity, Western Christian garment suspended from the shoulders. There are two types of scapulars, the Monasticism, monastic and Catholic devotions, devot ...

and pelvic girdles and

hindlimb A hindlimb or back limb is one of the paired articulated appendages (limbs) attached on the caudal ( posterior) end of a terrestrial tetrapod vertebrate's torso.http://www.merriam-webster.com/medical/hind%20limb, Merriam Webster Dictionary-Hindl ...

). The skull has a length of 18 centimeters, and ''Leyesaurus'' has been estimated to have been about in length. It was collected from the uppermost part of the Quebrada del Barro Formation of the Marayes-El Carrizal Basin, dating to the Lower Jurassic (based on the similarities between ''Leyesaurus'' and Lower Jurassic sauropodomorphs, like '' Massospondylus'' and ''

Adeopapposaurus ''Adeopapposaurus'' (meaning "far eating lizard", in reference to its long neck) is a genus of prosauropod dinosaur from the Early Jurassic Cañón del Colorado Formation of San Juan, Argentina. It was similar to ''Massospondylus''. Four parti ...

''). ''Leyesaurus'' was found near the locality Balde de Leyes, in the

Caucete Department Caucete is a department in the eastern part of the San Juan Province of Argentina, which is predominantly a landscape of mountains, and many plantations. It contains the popular Shrine of the Difunta Correa. Etymology The name is derived from ...

of San Juan Province. Within Massospondylidae, ''Leyesaurus'' was found to be most closely related to ''

''.

Etymology

''Leyesaurus'' was first named by Cecilia Apaldetti, Ricardo N. Martinez, Oscar A. Alcober and Diego Pol in

2011 File:2011 Events Collage.png, From top left, clockwise: a protester partaking in Occupy Wall Street heralds the beginning of the Occupy movement; protests against Libyan dictator Muammar Gaddafi, who was killed that October; a young man celebrate ...

and the type species is ''Leyesaurus marayensis''. The generic name honors the Leyes family, inhabitants of the small town Balde de Leyes, who discovered the holotype and notified the paleontologists of the San Juan Museum, and ''saurus'', Greek for "lizard". The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

refers to the Marayes-El Carrizal Basin, where the holotype was discovered.

Phylogeny

The following cladogram shows the position of ''Leyesaurus'' within Massopoda, according to Oliver W. M. Rauhut and colleagues, 2020:

References

Massospondylidae Dinosaur genera Early Jurassic dinosaurs of South America Jurassic Argentina Fossils of Argentina Geology of San Juan Province, Argentina Fossil taxa described in 2011 {{jurassic-reptile-stub