''Thalattosuchus'' 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 ...

of marine

crocodyliform Crocodyliformes is a clade of crurotarsan archosaurs, the group often traditionally referred to as "crocodilians". They are the first members of Crocodylomorpha to possess many of the features that define later relatives. They are the only pseudo ...

that lived in the oceans during the Middle to

Late Jurassic The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987. In European lithostratigraphy, the name ...

. ''Thalattosuchus'' was named in 2020. ''Thalattosuchus'' was a

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 ...

that spent much, if not all, its life out at sea. No ''Thalattosuchus'' eggs or nests have been discovered, so little is known of the reptile's life cycle, unlike other large marine reptiles of 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 ...

, such as

plesiosaur The Plesiosauria (; Greek: πλησίος, ''plesios'', meaning "near to" and ''sauros'', meaning "lizard") or plesiosaurs are an order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared ...

s or

ichthyosaurs Ichthyosaurs (Ancient Greek for "fish lizard" – and ) are large extinct marine reptiles. Ichthyosaurs belong to the order known as Ichthyosauria or Ichthyopterygia ('fish flippers' – a designation introduced by Sir Richard Owen in 1842, alt ...

which are known to have given birth to live young out at sea. Where ''Thalattosuchus'' mated, whether on land or at sea, is currently unknown. The name ''Thalattosuchus'' means "sea crocodile".

Discovery and species

Fossil specimens referrable to ''Thalattosuchus'' are known from Middle-Late Jurassic deposits of

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 b ...

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

and

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

.Steel R. 1973. Crocodylia. ''Handbuch der Paläoherpetologie, Teil 16''. Stuttgart: Gustav Fischer Verlag,116 pp. 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 ...

of ''Thalattosuchus'' was initially described as ''Crocodilus superciliosus'' in 1852. During the 1860s the species ''superciliosus'' was moved to the genera ''

Teleosaurus ''Teleosaurus'' (from el, τέλειος , 'perfect' and el, σαῦρος , 'lizard') is an extinct genus of teleosaurid crocodyliform found in the Middle Jurassic Calcaire de Caen Formation of France. It was approximately in length and w ...

'' and ''

Metriorhynchus ''Metriorhynchus'' is an extinct genus of marine crocodyliform that lived in the oceans during the Late Jurassic. The type species, ''M. brevirostris'' was named in 1829 as a species of ''Steneosaurus'' before being named as a separate genus by ...

''. The

type specimen In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...

of ''superciliosus'' was largely neglected in the literature, and was figured in 2018Brignon A., 2018. - Contexte historique de la collection Félix de Roissy (1771-1843) de reptiles marins jurassiques des Vaches Noires. ''Geodiversitas'' 40: 43-68, fasc. 2 and figured again in 2020 when the genus ''Thalattosuchus'' was created for the species. Only one species is recognised, the type species ''T. superciliosus''.

Description

Averaging in length, ''Thalattosuchus'' was similar size to modern crocodiles. However, it had a streamlined body and a finned tail, making it a more efficient swimmer than modern crocodylian species.Massare JA. 1988. Swimming capabilities of Mesozoic marine reptiles; implications for method of predation. ''Paleobiology'' 14 (2):187-205.

Palaeobiology

Salt glands

''Thalattosuchus'' had nasal salt glands which, like the salt glands of all other marine reptiles, were used to remove excess salt. This means that like ''

Cricosaurus ''Cricosaurus'' is an extinct genus of marine crocodyliforms of the Late Jurassic. belonging to the family Metriorhynchidae. The genus was established by Johann Andreas Wagner in 1858 for three skulls from the Tithonian (Late Jurassic) of German ...

'' it would have been able to "drink" salt-water and eat equally salty prey, such as

cephalopod A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...

s, without

dehydrating In physiology, dehydration is a lack of total body water, with an accompanying disruption of Metabolism, metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental tempe ...

.Fernández M, Gasparini Z. 2008. Salt glands in the Jurassic metriorhynchid ''Geosaurus'': implications for the evolution of osmoregulation in Mesozoic crocodyliforms. ''Naturwissenschaften'' 95: 79-84.

References

{{Taxonbar, from=Q101111435 Late Jurassic crocodylomorphs of Europe Prehistoric pseudosuchian genera Prehistoric marine crocodylomorphs Late Jurassic genus extinctions Thalattosuchians Fossil taxa described in 2020

Discovery and species

Description

Palaeobiology

Salt glands

See also

References