''Baptanodon'' is an

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 ...

of the

Late Jurassic The Late Jurassic is the third Epoch (geology), epoch of the Jurassic Period, and it spans the geologic time scale, geologic time from 161.5 ± 1.0 to 143.1 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic stratum, strata.Owen ...

period (160-156 million years ago), named for its supposed lack of teeth (although teeth of this genus have since been discovered). It had a graceful long dolphin-shaped body, and its jaws were well adapted for catching squid. Major fossil finds of this genus have been recorded in

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

. The type species, ''Sauranodon natans'', was originally included under ''Sauranodon'' in 1879,O. C. Marsh. 1879. A new order of extinct reptiles (Sauranodonta), from the Jurassic Formation of the Rocky Mountains. ''The American Journal of Science and Arts, series 3'' but this name was preoccupied.

Discovery and species

''Baptanodon'' is a replacement name for ''Sauranodon'' applied to ichthyosaur material in 1879 and was moved to its own genus ''Baptanodon'' in 1880 when ''Sauranodon'' was found to be preoccupied. ''Baptanodon'' was considered a

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. ...

of ''

Ophthalmosaurus ''Ophthalmosaurus'' (Greek ὀφθάλμος ''ophthalmos'' 'eye' and σαῦρος ''sauros'' 'lizard') is a genus of ichthyosaur known from the Middle-Late Jurassic. Possible remains from the earliest Cretaceous, around 145 million years ago, a ...

'' by Maisch & Matzke (2000).Maisch MW, Matzke AT. 2000. The Ichthyosauria. ''Stuttgarter Beiträge zur Naturkunde, Serie B (Geologie und Paläontologie)'' 298: 1-159. However, cladistic analyses published in the 2010s indicate that ''Baptanodon'' is not congeneric with ''Ophthalmosaurus icenicus''.

Classification

The cladogram below follows Fischer ''et al.'' 2012.

Palaeobiology

Fossils of ''Baptanodon'' have been found in the Oxfordian-age

Sundance Formation The Sundance Formation is a western North American sequence of Middle Jurassic to Upper Jurassic age Dating from the Bathonian to the Oxfordian, around 168-157 Ma, It is up to 100 metres thick and consists of marine shale, sandy shale, sandstone ...

of Wyoming, which also has yielded fossils of the cryptoclidids ''

Tatenectes ''Tatenectes'' is a genus of cryptoclidid plesiosaur known from the Upper Jurassic of Wyoming. Its remains were recovered from the Redwater Shale Member of the Sundance Formation, and initially described as a new species of '' Cimoliosaurus' ...

'' and '' Pantosaurus'', and the pliosaurid ''

Megalneusaurus ''Megalneusaurus'' is an extinct genus of large pliosaurs that lived during the Oxfordian and Kimmeridgian stages of the Late Jurassic in what is now North America. It was provisionally described as a species of '' Cimoliosaurus'' by the geologi ...

''.Marsh, O. C., 1880, Note on Sauranodon: ''American Journal of Science, 3rd series'', v. 19, n. 4, p. 491.Marsh, O. C., 1895, The Reptilia of the Baptanodon Beds: American ''Journal of Science, 3rd series'', v. 34., n. 299, p. 405-406.

References

{{Taxonbar, from=Q55604865 Ophthalmosaurinae Late Jurassic ichthyosaurs Jurassic reptiles of North America Late Jurassic extinctions Fossil taxa described in 1880 Ichthyosauromorph genera

Discovery and species

Classification

Palaeobiology

See also

References