Askeptosauridae is a family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 of thalattosaur

Thalattosaur

Thalattosaurs are a group of prehistoric marine reptiles which lived during the mid-late Triassic Period. Some species of thalattosaur grew to over 4 meters in length, including a long, flattened tail used in underwater propulsion...

s within the superfamily Askeptosauroidea

Askeptosauroidea

Askeptosauroidea is a superfamily of thalattosaurs, a Triassic group of marine reptiles. Askeptosauroidea is one of two major subgroups of Thalattosauria, the other being Thalattosauroidea...

. Fossils have been found from Italy

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

, Switzerland

Switzerland

Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

, and China

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

. Askeptosaurids are distinguished from other thalattosaurs by their long necks and narrow skulls.

Classification

Askeptosauridae was named in 1952 to include the genus Askeptosaurus

Askeptosaurus

Askeptosaurus is an extinct genus of aquatic reptile related to the thalattosaurian group. Their remains have been found in Italy and Switzerland.Askeptosaurus was a very thin, elongated creature, that probably swam like an eel...

. In 2000, the genus Anshunsaurus

Anshunsaurus

Anshunsaurus is a genus of thalattosaurs within the family Askeptosauridae. Fossils have been found from Middle Triassic deposits in Guizhou, China. Three species are known: the type species A. huangguoshuensis , the slightly older species A. wushaensis , and the species A...

, which includes two species, was added to the family. In a 2005 phylogenetic analysis, Endennasaurus

Endennasaurus

Endennasaurus is an extinct genus of thalattosaurian from the Upper Triassic of Italy....

was included within Askeptosauridae. Later that year a new study placed Endennasaurus outside Askeptosauridae as a basal

Basal (phylogenetics)

In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...

 member of Askeptosauroidea. More recent studies have placed the genus Miodentosaurus

Miodentosaurus

Miodentosaurus is a genus of thalattosaurian from the Late Triassic of China.-Sources:*...

from China

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

 in the family as well. Below is a cladogram

Cladogram

A cladogram is a diagram used in cladistics which shows ancestral relations between organisms, to represent the evolutionary tree of life. Although traditionally such cladograms were generated largely on the basis of morphological characters, DNA and RNA sequencing data and computational...

 modified from Wu et al. (2009) showing the phylogenetic relationships of askeptosaurids: