''Prosantosaurus'' is a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

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 ...

of pachypleurosaurian

sauropterygian Sauropterygia (" lizard flippers") is an extinct taxon of diverse, aquatic reptiles that developed from terrestrial ancestors soon after the end-Permian extinction and flourished during the Triassic before all except for the Plesiosauria bec ...

containing the single species ''Prosantosaurus scheffoldi'' discovered in Canton Grison of Switzerland. The genus is named after the Prosanto Formation near the Ducan mountains, where the skeletons were found, and the species for Beat Scheffold, a scientific illustrator from Zurich who contributed prominently to the research of the

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

marine reptiles.

Discovery

Six skeletons of the species have been discovered within

lime Lime commonly refers to: * Lime (fruit), a green citrus fruit * Lime (material), inorganic materials containing calcium, usually calcium oxide or calcium hydroxide * Lime (color), a color between yellow and green Lime may also refer to: Botany ...

and

marlstone Marl is an earthy material rich in carbonate minerals, clays, and silt. When hardened into rock, this becomes marlstone. It is formed in marine or freshwater environments, often through the activities of algae. Marl makes up the lower part ...

sediments of the Upper Prosanto Formation in the Ducanfurgga southeast of

Davos , neighboring_municipalities= Arosa, Bergün/Bravuogn, Klosters-Serneus, Langwies, S-chanf, Susch , twintowns = } Davos (, ; or ; rm, ; archaic it, Tavate) is an Alpine resort town and a municipality in the Prättigau/Davos R ...

, Canton Grisons, at about 2700 m above sea level. They have been dated to the very early

Ladinian The Ladinian is a stage and age in the Middle Triassic series or epoch. It spans the time between Ma and ~237 Ma (million years ago). The Ladinian was preceded by the Anisian and succeeded by the Carnian (part of the Upper or Late Triassic). ...

of the

period. Today, the Ducan mountains are located about northeast of Mount San Giorgio, a

UNESCO world heritage A World Heritage Site is a landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites are designated by UNESCO for h ...

site where other pachypleurosauria were found. In the past, the two locations have been up to apart from each other. The skeletons are accessible in the palaentological institute of the

University of Zurich The University of Zürich (UZH, german: Universität Zürich) is a public research university located in the city of Zürich, Switzerland. It is the largest university in Switzerland, with its 28,000 enrolled students. It was founded in 1833 f ...

Description

''Prosantosaurus scheffoldi'' were long lizard-like

vertebrate Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...

s inhabiting the coastal areas of the

Tethys Ocean The Tethys Ocean ( el, Τηθύς ''Tēthús''), also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean that covered most of the Earth during much of the Mesozoic Era and early Cenozoic Era, located between the ancient continents ...

in the

Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceo ...

era. The Tethys Ocean covered large parts of the present-day Switzerland. Their teeth are less pointed and also broader at their basis from comparable pachypleurosaurs. If its teeth broke off, they regrew. The regrowing teeth were observed for the first time on a European pachypleurosaurus, the other discovery having occurred on a pachypleuosaurus in China. ''Prosantosaurus'' were

carnivore A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...

s and it is assumed they fed on small fishes and

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

s which it swallowed whole after hunting them down. Other bones that differ from other known pachypleurosaurus are those at the calvaria and the

rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ships * Ros ...

. Research comparing the new species to other European pachypleurosaurs such as '' Anarosaurus'' or ''

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 ...

'' has been conducted by a team of palaeontologists at the University of Zurich.

References

{{Taxonbar, from=Q113124598 Triassic reptiles Fossils of Switzerland Fossil taxa described in 2022 Nothosaurs Ladinian genera