''Nothosaurus'' ('false lizard', from the Ancient Greek and ) is an extinct genus of

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

reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

from the

Triassic The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...

period, approximately 245–228 million years ago, with fossils being distributed throughout the former

Tethys Ocean The Tethys Ocean ( ; ), also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean during much of the Mesozoic Era and early-mid Cenozoic Era. It was the predecessor to the modern Indian Ocean, the Mediterranean Sea, and the Eurasia ...

, from

North Africa North Africa (sometimes Northern Africa) is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region. However, it is sometimes defined as stretching from the Atlantic shores of t ...

and

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. It is the best known member of the nothosaur order.

Description

''Nothosaurus'' was a semi-

ocean The ocean is the body of salt water that covers approximately 70.8% of Earth. The ocean is conventionally divided into large bodies of water, which are also referred to as ''oceans'' (the Pacific, Atlantic, Indian Ocean, Indian, Southern Ocean ...

ic animal which probably had a lifestyle similar to that of today's

seal Seal may refer to any of the following: Common uses * Pinniped, a diverse group of semi-aquatic marine mammals, many of which are commonly called seals, particularly: ** Earless seal, also called "true seal" ** Fur seal ** Eared seal * Seal ( ...

s. It was about , with long, webbed toes and possibly a fin on its tail. However, some species such as ''N. zhangi'' and ''N. giganteus'' were larger, up to . When swimming, ''Nothosaurus'' would use its tail, legs, and webbed feet to propel and steer it through the water. The skull was broad and flat, with long jaws, lined with needle

teeth A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

, it probably caught fish and other marine creatures. Trackways attributed, partly by process of elimination, to a nothosaur, that were reported from

Yunnan Yunnan; is an inland Provinces of China, province in Southwestern China. The province spans approximately and has a population of 47.2 million (as of 2020). The capital of the province is Kunming. The province borders the Chinese provinces ...

, China in June 2014, were interpreted as the paddle impressions left as the animals dug into soft seabed with rowing motions of their paddles, churning up hidden benthic creatures that they snapped up.(LiveScience) Tia Ghose, "Ancient long-necked 'sea monsters' rowed their way to prey", reporting the scientific article published in ''Nature Communications'' 11 June 2014: accessed 28 November 2014.
/ref> Once caught, few animals would be able to shake themselves free from the mouth of ''Nothosaurus''. In many respects its body structure resembled that of the much later

plesiosaur The Plesiosauria or plesiosaurs are an Order (biology), order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared in the latest Triassic Period (geology), Period, possibly in the Rhaetian st ...

s, but it was not as well adapted to an aquatic environment. It is thought that one branch of the nothosaurs may have evolved into pliosaurs such as '' Liopleurodon'', a short-necked plesiosaur that grew up to , and the long-necked '' Cryptoclidus'', a fish eater with a neck as long as .

Species

There are nearly a dozen known species of ''Nothosaurus''. The type species is ''N. mirabilis'', named in 1834 from the Germanic

Muschelkalk The Muschelkalk (German for "shell-bearing limestone"; ) is a sequence of sedimentary rock, sedimentary rock strata (a lithostratigraphy, lithostratigraphic unit) in the geology of central and western Europe. It has a Middle Triassic (240 to 230 m ...

. Other species include ''N. giganteus'' (previously known as ''Paranothosaurus'') from

Osnabrück Osnabrück (; ; archaic English: ''Osnaburg'') is a city in Lower Saxony in western Germany. It is situated on the river Hase in a valley penned between the Wiehen Hills and the northern tip of the Teutoburg Forest. With a population of 168 ...

, Germany; ''N. juvenilis'', also from Germany; ''N. edingerae'' from the Upper Muschelkalk and Lower Keuper; ''N. haasi'' and ''N. tchernovi'' from

Makhtesh Ramon Makhtesh Ramon (; ''lit.'' Ramon Crater/ Makhtesh; ; ''lit.'' The Ruman Wadi) is a geological feature of Israel's Negev desert. Located some 85 km south of Beersheba, the landform is the world's largest "erosion cirque" (steephead valley ...

Israel Israel, officially the State of Israel, is a country in West Asia. It Borders of Israel, shares borders with Lebanon to the north, Syria to the north-east, Jordan to the east, Egypt to the south-west, and the Mediterranean Sea to the west. Isr ...

; ''N. cymatosauroides'' from the Spanish Muschelkalk; ''N. jagisteus'' from the Upper Muschelkalk of

Hohenlohe The House of Hohenlohe () is a German princely dynasty. It formerly ruled an immediate territory within the Holy Roman Empire, which was divided between several branches. In 1806, the area of Hohenlohe was 1,760 km² and its estimated pop ...

, Germany; and ''N. youngi'', ''N. yangjuanensis'' (and its junior synonym ''N. rostellatus'') and the recently named ''N. zhangi'' from

Guizhou ) , image_skyline = , image_caption = , image_map = Guizhou in China (+all claims hatched).svg , mapsize = 275px , map_alt = Map showing the location of Guizhou Province , map_caption = Map s ...

. Several species have been described from the Lower Muschelkalk in

Winterswijk Winterswijk (; also known as ''Winterswiek'' or ''Wenters'') is a Municipalities of the Netherlands, municipality and a town in the eastern Netherlands. It has a population of and is situated in the Achterhoek, which lies in the easternmost part ...

, the

Netherlands , Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...

, including ''N. marchicus'' (and its

junior synonym In taxonomy, the scientific classification of living organisms, a synonym is an alternative scientific name for the accepted scientific name of a taxon. The botanical and zoological codes of nomenclature treat the concept of synonymy differently. ...

''N. winterswijkensis'') and ''N. winkelhorsti''. Recently, the long considered lost type material of ''N. schimperi'' Meyer, 1842 from the Lower Muschelkalk of Soultz-les-Bains, Alsace, France, has been rediscovered and a lectotype has been designated. Klein and Albers (2009) conducted a

phylogenetic analysis In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data ...

, but did not test the

monophyly In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent comm ...

of ''Nothosaurus'', as other nothosaurids were not included in their analysis. Several other species have been named but are now generally considered invalid. One such species, ''N. procerus'', is now considered a junior subjective synonym of ''N. marchicus''. Other species now considered junior synonyms of ''N. marchicus'' include ''N. crassus'', ''N. oldenburgi'', ''N. raabi'', ''N. schroderi'', ''N. venustus'' and the recently named ''N. winterswijkensis''. Junior synonyms of ''N. giganteus'', the second largest ''Nothosaurus'' species, include ''N. andriani'', ''N. angustifronis'', ''N. aduncidens'', ''N. baruthicus'' and ''N. chelydrops''. A species level

of Nothosauridae was performed by Liu ''et al.'' (2014), and included all known valid species of the family and ''Nothosaurus'' apart from '' Lariosaurus stensioi'' (type of ''Micronothosaurus''), ''Nothosaurus cymatosauroides'', and '' Ceresiosaurus lanzi''. Due to the inclusion of other nothosaurids other than ''Nothosaurus'', the

of ''Nothosaurus'' was tested for the first time. The analysis found both '' Lariosaurus'' and ''Nothosaurus'' to be

polyphyletic A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

in regard to each other and all the other genera of the family, making a systematic revision of these two genera necessary. Below, their results are shown with type species of named nothosaurid genera noted. Later, in 2017, the species ''N. juvenilis'', ''N. youngi'', and ''N. winkelhorsti'' were formally moved to ''Lariosaurus''.

References

* Parker, Steve. Dinosaurus: the complete guide to dinosaurs. Firefly Books Inc, 2003. Pg. 384

General references

* Dixon, Dougal (2006). ''The Complete Book of Dinosaurs''. Hermes House. * Haines, Tim, and Paul Chambers. ''The Complete Guide to Prehistoric Life''. Pg. 64. Canada: Firefly Books Ltd., 2006 {{Taxonbar, from=Q910989 Triassic reptiles of Asia Triassic reptiles of Europe Nothosaurs Triassic sauropterygians Triassic reptiles of Africa Early Triassic first appearances Olenekian genera Anisian genera Ladinian genera Carnian genera Norian genus extinctions Sauropterygian genera Fossil taxa described in 1834