''Ornithotarsus'' () is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

hadrosaurid Hadrosaurids (), or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which inclu ...

ornithopod Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (), that started out as small, bipedal running grazers and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous world ...

dinosaurs Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

that lived in

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

during the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...

Period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

in what is now the

Merchantville Formation The Merchantville Formation is a geological formation in the northeastern United States whose strata date back to the Late Cretaceous, around the time of the Santonian and Campanian age. Dinosaur remains are among the fossils that have been recove ...

about 84 million to 78 million years ago.

Taxonomy

''Ornithotarsus immanis'' was described in 1869 on the basis of YPM 3221, a fragmentary hindlimb comprising a distal tibia and fibula as well as ankle bones unearthed from the Merchantville Formation of Raritan Bay of New Jersey. Although subsequently treated as a synonym of ''

Hadrosaurus ''Hadrosaurus'' (; ) is a genus of hadrosaurid ornithopod dinosaurs that lived in North America during the Late Cretaceous Period in what is now the Woodbury Formation about 80 million to 78 million years ago. The holotype specimen was found in f ...

'', Prieto-Marquez et al. (2006) found ''Ornithotarsus'' to share no diagnostic traits with the ''H. foulkii'' holotype and declared it a ''nomen dubium'' undetermined beyond Hadrosauridae, and Brownstein (2021) agreed with this assessment.Brownstein, C., 2021. Dinosaurs from the Santonian–Campanian Atlantic coastline substantiate phylogenetic signatures of vicariance in Cretaceous North America. ''Royal Society Open Science'' 8 (8): 210127 .

References

{{Taxonbar, from=Q3886098 Late Cretaceous dinosaurs of North America Hadrosaurs Fossil taxa described in 1869 Paleontology in New Jersey Ornithischian genera Taxa named by Edward Drinker Cope