Named By: Merriam - 1903.
Synonyms: Merriamia, Leptocheirus?
Classification: Chordata, Reptilia, Ichthyopterygia, Ichthyosaura, Toretocnemidae.
Species: T. californicus (type), T. zitteli.
Size: Uncertain, but probably not more than 2 meters long at most.
Known locations: USA, California, Shasta county - Hosselkus Limestone.
Time period: Carnian of the Triassic.
Fossil representation: At least two specimens.
a late Triassic ichthyosaur, Toretocnemus displays
some features that
show a trend similar to that seen in other transitory ichthyosaurs like
developing the advanced features that are more commonly
associated with later forms like Ichthyosaurus.
For a long time
Toretocnemus was the only member of its group of
ichthyosaurs until the
addition of Qianichthyosaurus.
In 1904 another ichthyosaur described and named was Merriamia zitteli, however a 2000 review by M. W. Maisch and A. T. Matzke found it to be the same as Toretocnemus. Thus the fossil material originally referred to as Merriamia was used to establish the second Toretocnemus species T. zitteli. Additionally remains originally named as Leptocheirus have been renamed Toretocnemus by the same study.