''Cryptovaranoides'' ("hidden lizard-like animal") 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 ...

from the

Late Triassic The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch ...

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...

. It contains a single species, ''Cryptovaranoides microlanius''. It is represented by a holotype partial skeleton as well as referred isolated bones from

Rhaetian The Rhaetian is the latest age of the Triassic Period (in geochronology) or the uppermost stage of the Triassic System (in chronostratigraphy). It was preceded by the Norian and succeeded by the Hettangian (the lowermost stage or earliest ...

-aged fissure fill-deposits in Cromhall Quarry, near Tortworth, Gloucestershire preserved alongside the common fossil

rhynchocephalian Rhynchocephalia (; ) is an order of lizard-like reptiles that includes only one living species, the tuatara (''Sphenodon punctatus'') of New Zealand. Despite its current lack of diversity, during the Mesozoic rhynchocephalians were a diverse gro ...

'' Clevosaurus''. The type specimen had been collected in 1953, but was only described as a distinct taxon in 2022. Several traits such as braincase, neck vertebrae, skull architecture, and teeth arrangement support ''Cryptovaranoides''' classification as a squamate. ''Cryptovaranoides'' marks the earliest known occurrence of a

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. ...

squamate, with previous fossils known only as early as the

Middle Jurassic The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations ...

; the discovery of ''Cryptovaranoides'' pushes back the estimated origin of modern squamates by 35 million years. A phylogenetic analysis placed ''Cryptovaranoides'' within the Anguimorpha as

sister A sister is a woman or a girl who shares one or more parents with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a familial relationship, it is sometimes used endearingly to refer to ...

to the Neoanguimorpha (containing modern helodermatids, anguids, and knob-scaled lizards), supporting a much more ancient estimate for the radiation of modern squamate lineages than previously assumed.

References

{{Taxonbar, from=Q115604719 Anguimorpha Triassic England Taxa named by Michael Benton Fossil taxa described in 2022