''Odoiporosaurus'' 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 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 ...

pachypleurosaur left, 220px, '' Pachypleurosaurus'' Pachypleurosauria is an extinct clade of primitive sauropterygian reptiles that vaguely resembled aquatic lizards, and were limited to the Triassic period. They were elongate animals, ranging in size from , w ...

known from the

Middle Triassic In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided in chronostratigraphy. The Middle Triassic spans the time between Ma and ...

(middle

Anisian In the geologic timescale, the Anisian is the lower stage or earliest age of the Middle Triassic series or epoch and lasted from million years ago until million years ago. The Anisian Age succeeds the Olenekian Age (part of the Lower Triassic Ep ...

stage)

Besano Formation The Besano Formation is a geological formation in the southern Alps of northwestern Italy and southern Switzerland. This formation, a short but fossiliferous succession of dolomite and black shale, is famous for its preservation of Middle Triassic ...

(Grenzbitumenzone) of northern

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical re ...

. It contains a single species, ''Odoiporosaurus teruzzii''. ''Odoiporosaurus'' is the

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

of the group formed by ''

Serpianosaurus ''Serpianosaurus'' is an extinct genus of pachypleurosaurs known from the Middle Triassic (late Anisian and early Ladinian stages) deposits of Switzerland and Germany. It was a small reptile, with the type specimen of ''S. mirigiolensis'' meas ...

'' and ''

Neusticosaurus ''Neusticosaurus'' (sometimes misspelled ''Neuticosaurus'') ("swimming lizard"), is an extinct genus of marine reptile belonging to the pachypleurosaurs, from Italy, Switzerland and Germany. ''Neusticosaurus'' was one of the smallest nothosaur ...

'', and together with the older and more primitive '' Dactylosaurus'' plus '' Anarosaurus''

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

, they form a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

group of European pachypleurosaurids.

References

Triassic plesiosaurs Fossil taxa described in 2014 Fossils of Italy Anisian life Sauropterygian genera {{triassic-reptile-stub