''Californosaurus'' ('California lizard') is an extinct

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

ichthyosaur Ichthyosauria is an order of large extinct marine reptiles sometimes referred to as "ichthyosaurs", although the term is also used for wider clades in which the order resides. Ichthyosaurians thrived during much of the Mesozoic era; based on fo ...

, an extinct marine reptile, from the Lower

Hosselkus Limestone The Hosselkus Limestone is an Upper Triassic fossiliferous marine micrite, micritic limestone Formation (stratigraphy), formation that outcrops in Plumas County, California, Plumas and Shasta County, California, Shasta Counties, California. It is ...

(

Carnian The Carnian (less commonly, Karnian) is the lowermost stage (stratigraphy), stage of the Upper Triassic series (stratigraphy), Series (or earliest age (geology), age of the Late Triassic Epoch (reference date), Epoch). It lasted from 237 to 227.3 ...

Late Triassic The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch a ...

) of

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, and also the

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 ...

(

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 ...

Middle Triassic In the geologic timescale, the Middle Triassic is the second of three epoch (geology), epochs of the Triassic period (geology), period or the middle of three series (stratigraphy), series in which the Triassic system (stratigraphy), system is di ...

) of Germany.

Taxonomy

John Campbell Merriam John Campbell Merriam (October 20, 1869 – October 30, 1945) was an American paleontologist, educator, and conservationist. The first vertebrate paleontologist on the West Coast of the United States, he is best known for his taxonomy of ve ...

(1902) described it as a new species of ''

Shastasaurus ''Shastasaurus'' ("Mount Shasta lizard") is an extinct genus of ichthyosaur from the Late Triassic.Hilton, Richard P., ''Dinosaurs and Other Mesozoic Animals of California'', University of California Press, Berkeley 2003 , at pages 90-91. Specime ...

'', ''S. perrini'', honouring Professor

James Perrin Smith James Perrin Smith (November 27, 1864 – January 1, 1931) was an American geologist and paleontologist. Smith was of English descent. T. M. Forster, one of his ancestors, was a surgeon in the Royal Navy and moved to Virginia in 1745. His patern ...

as discoverer, based on

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

UCMP 9119. He later recognized the species as generically distinct from the ''Shastasaurus'' type species, in 1905 erecting ''

Delphinosaurus ''Delphinosaurus'' is a dubious genus of ophthalmosaurid ichthyosaur from Albian-Cenomanian deposits in the Kursk region of European Russia. Merriam (1905) erected ''Delphinosaurus'' for the Late Triassic ichthyosaur ''Shastasaurus perrini'' f ...

'' for ''S. perrini''. However, ''Delphinosaurus'' had in 1853 by Eichwald been previously used for an ophthalmosaurid from Albian-Cenomanian deposits in European Russia, ''Delphinosaurus kiprijanoffii'', and Oscar Kuhn (1934) provided the generic replacement name ''Californosaurus''. Merriam (1938) independently erected ''Perrinosaurus'' to replace ''Delphinosaurus'', but this is a junior objective synonym.

Description

The long-snouted head is small in comparison with the rest of the body, as in basal ichthyosaurs such as ''

Mixosaurus ''Mixosaurus'' is an extinct genus of Middle Triassic (Anisian to Ladinian, about 250-240 Mya) ichthyosaur. Its fossils have been found near the Italy–Switzerland border and in South China. The genus was named in 1887 by George H. Baur. The n ...

'' and ''

Cymbospondylus ''Cymbospondylus'' (meaning "cupped vertebrae") is an extinct genus of large ichthyosaurs, of which it is among the oldest representatives, that lived from the Lower to Middle Triassic in what are now North America and Europe. The first known fo ...

''. The tail is sharply turned downwards, in common with more advanced ichthyosaurs, with a small vertical fluke. It may have had a small dorsal fin. There is a small number of pre-sacral vertebrae (45 or 50). The phalanges (digit bones) are circular and widely spaced, giving the flipper a round appearance. It was a medium-sized ichthyosaur, measuring up to long.

Biology

It fed on fish and other small marine creatures. Like other ichthyosaurs it probably never ventured onto dry land, and gave birth in the water.

References

External links

Palaeos Vertebrates

Late Triassic ichthyosaurs of North America Fauna of California Paleontology in California Triassic California Late Triassic first appearances Late Triassic extinctions Fossil taxa described in 1934 Ichthyosauromorph genera {{triassic-reptile-stub

Taxonomy

Description

Biology

See also

References

External links