Toretocnemus

Toretocnemus (meaning 'perforated tibia') is an extinct genus of ichthyosaurs that lived during the Carnian stage of the Upper Triassic in what is now North America. Two species are known, T. californicus and T. zitelli, first described in 1903 by John Campbell Merriam from fossils discovered in the Hosselkus Limestone, Shasta County. The second species was first seen by Merriam as belonging to a distinct genus, but in 1999 it was reclassified into the original taxon. Toretocnemus fossils are primarily known from California, although some specimens are also reported from Alaska and Mexico. With Qianichthyosaurus, the taxon is part of the Toretocnemidae, of which it is also the type genus.

==History of research== thumb|left|upright|Clavicles and [[interclavicle (top) and scapula and coracoids (bottom) of T. zitteli]] The specimen that would eventually be cataloged as UCMP 8100 was found along the Pit River in Shasta County, California, by Annie Montague Alexander. While much of the specimen had been lost to erosion, many elements were still preserved, namely some skull fragments, around 30 vertebrae, including some dorsal (trunk) vertebrae, but being mostly represented by frontwards caudal (tail) vertebrae, a large number of ribs, the pelvis, the right forelimb, and both the left and right hindlimbs. Another specimen, UCMP 8099, was also found by Alexander in Shasta County. This one was uncovered on a ranch and consisted of a partial skull, various incomplete vertebrae, poorly-preserved ribs, gastralia (belly ribs), the shoulder girdle, forelimbs, and a partial hindlimb. Both of these specimens came form the Trachyceras zone of the Hosselkus Limestone. Alexander gave them, in addition to multiple other fossil reptiles, to the University of California around 1903.