Toxolophosaurus

{{Short description|Extinct genus of reptiles}}

{{Italic title}}

{{Taxobox

| name = Toxolophosaurus

| fossil_range = {{fossil_range|145|100|Early Cretaceous}}

| regnum = Animalia

| phylum = Chordata

| classis = Reptilia

| ordo = Rhynchocephalia

| subordo = Sphenodontia

| unranked_familia = †Opisthodontia

| subfamilia = †Eilenodontinae

| genus = †Toxolophosaurus Olson, 1960{{cite web |url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=37830 |title=†Toxolophosaurus Olson 1960 |work=Paleobiology Database |publisher=Fossilworks |access-date=17 December 2021}}

| subdivision_ranks = Species

| subdivision = *{{extinct}}T. cloudi (type) Olson, 1960

}}

Toxolophosaurus was a sphenodont which lived in North America during the Early Cretaceous.{{cite journal |title=A Trilophosaurid Reptile from the Kootenai Formation (Lower Cretaceous) |author=Everett C. Olson |journal=Journal of Paleontology |volume=34 |issue=3 |date=May 1960 |pages=551–555 |jstor=1300954}}

The first specimen, consisting of a pair of lower jaws, was found by George Cloud and described by Everett C. Olson in 1960 in the Kootenai Formation of Montana, 223.75 feet above the base of the Kootenai. Olson originally classified Toxolophosaurus as a member of the family Trilophosauridae, which was a group of primitive lizard-like reptiles which lived during the Triassic Period, although he provided no reasons for this decision. In 1981, Toxolophosaurus was reassigned to the family Sphenodontidae, on the basis that the specimens were more similar to Sphenodon than to members of Trilophosauridae.{{cite journal|last1=Throckmorton|first1=Gaylord S.|last2=Hopson|first2=James A.|last3=Parks|first3=Peter|title=A redescription of Toxolophosaurus cloudi Olson, a Lower Cretaceous herbivorous sphenodontid reptile |journal=Journal of Paleontology |date=1981 |volume=55 |issue=3 |pages=586–597 |url=http://jpaleontol.geoscienceworld.org/cgi/content/abstract/55/3/586 |jstor=1304272}} This classification was confirmed in 1985 by Michael Benton.{{cite web |url=http://www.fossilworks.org/cgi-bin/bridge.pl?a=displayTaxonomicData&reference_no=19680&display=opinions |title=Taxonomic opinions tied to this reference: M. J. Benton 1985 |work=Paleobiology Database |publisher=Fossilworks |access-date=17 December 2021}} It is closely related to Priosphenodon and Eilenodon.

In addition to the specimen recovered from Montana, numerous sphenodont fossils which have been ascribed to Toxolophosaurus have also been found within the Yellow Cat Member of the Cedar Mountain Formation.{{cite journal|last1=Kirkland|first1=James I.|last2=Suarez|first2=Marina|last3=Suarez|first3=Celina|last4=Hunt-Foster|first4=ReBecca|title=The Lower Cretaceous in East-Central Utah—The Cedar Mountain Formation and its Bounding Strata |journal=Geology of the Intermountain West |date=2016 |volume=3 |pages=101-228}}

Toxolophosaurus was herbivorous.{{cite journal|last1=Throckmorton|first1=Gaylord S.|last2=Hopson|first2=James A.|last3=Parks|first3=Peter|title=A redescription of Toxolophosaurus cloudi Olson, a Lower Cretaceous herbivorous sphenodontid reptile |journal=Journal of Paleontology |date=1981 |volume=55 |issue=3 |pages=586–597 |url=http://jpaleontol.geoscienceworld.org/cgi/content/abstract/55/3/586 |jstor=1304272}}