''Hoyalacerta'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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 alt ...

known from the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

''Hoyalacerta sanzi'', which is from the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

Las Hoyas fossil site in Spain. ''Hoyalacerta'' was named in 1999 and is considered either a member of the group

Iguania Iguania is an infraorder of squamate reptiles that includes iguanas, chameleons, agamids, and New World lizards like anoles and phrynosomatids. Using morphological features as a guide to evolutionary relationships, the Iguania are believed t ...

or a

stem Stem or STEM may refer to: Plant structures * Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang * Stipe (botany), a stalk to support some other structure * Stipe (mycology), the stem of a mushro ...

squamate Squamata (, Latin ''squamatus'', 'scaly, having scales') is the largest order of reptiles, comprising lizards, snakes, and amphisbaenians (worm lizards), which are collectively known as squamates or scaled reptiles. With over 10,900 species, ...

, meaning that it lies outside the squamate

crown group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...

that includes all living lizards and snakes. ''Hoyalacerta'' is a small lizard with an elongated body and short limbs. It is thought to have spent most of its time on the ground. Several other lizards are also known from Las Hoyas, including ''

Meyasaurus ''Meyasaurus'' is an extinct genus of Teiid lizard known from the Barremian of Spain and the Isle of Wight, UK. Four species are known from Spain, from the La Huérguina, Camarillas, and La Pedrera de Rúbies Formations while an indeterminate ...

'' (thought to have lived near the water), '' Scandensia'' (thought to be a climber), and '' Jucaraseps'' (which, like ''Hoyalacerta'', probably lived on the ground away from water). Features of ''Hoyalacerta'' that distinguish it from other Las Hoyas lizards include smooth skull bones, simple cone-shaped teeth, and short limbs relative to body length.

References

Cretaceous lizards Fossils of Spain La Huérguina Formation Fossil taxa described in 1999 {{paleo-lizard-stub