''Pneumatoarthrus'' is an extinct genus of

sea turtle Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerh ...

known from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent 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 ''cre ...

(early

Maastrichtian The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...

) Mount Laurel Formation of

Monmouth County, New Jersey Monmouth County () is a county located in the central portion of the U.S. state of New Jersey. It is bordered to its west by Mercer and Middlesex Counties, to its south by Ocean County, to its east by the Atlantic Ocean, and to its north ...

. Only a single species, ''P. peloreus'', is known.

Taxonomy

The holotype of ''Pneumatoarthrus'', ANSP 9225, was originally identified as a sacrum belonging to ''

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 in New Jersey about 83.6 to 77.9 Ma. The holotype specimen was found in flu ...

'' by Joseph Leidy in an 1865 monograph on Cretaceous reptiles from the US.Leidy, 1865. Memoir on the extinct reptiles of the Cretaceous formations of the United States. ''Smithsonian Contributions to Knowledge''. 14(6), 135 pp.

Edward Drinker Cope Edward Drinker Cope (July 28, 1840 – April 12, 1897) was an American zoologist, paleontology, paleontologist, comparative anatomy, comparative anatomist, herpetology, herpetologist, and ichthyology, ichthyologist. Born to a wealthy Quaker fam ...

later identified it belonging to a dinosaur more closely related to '' Anchisaurus'', ''

Efraasia ''Efraasia'' (pronounced "E-FRAHS-ee-A") is a genus of basal (phylogenetics), basal sauropodomorph dinosaur. It was a herbivore which lived during the middle Norian stage of the Late Triassic, around 210 million years ago, in what is now Germ ...

'', and '' Clepsysaurus'' than to '' Dryptosaurus'' and '' Ornithopsis'',Cope, 1870. Observations on the Reptilia of the Triassic formations of the Atlantic region of the United States. Proceedings of the American Philosophical Society. 11, 444-446. and in his 1872 description of the sea turtle ''

Protostega ''Protostega'' ('first roof') is an extinct genus of sea turtle containing a single species, ''Protostega gigas''. Its fossil remains have been found in the Smoky Hill Chalk formation of western Kansas (''Hesperornis'' zone, dated to 83.5 millio ...

'' he decided that ''Pneumatoarthrus'' was likely a sea turtle as well, which he reiterated in his 1875 monograph on Cretaceous vertebrate fossils from the Western Interior. Later authors overlooked Cope's 1875 monograph and considered it either a theropod or a hadrosaur (Huene 1932 considered ''Pneumatoarthrus'' the sacral vertebrae of ''Dryptosaurus''). Baird (1979) confirmed the protostegid identification of ''Pneumatoarthrus'' by Cope (1872, 1875) based on examination of ANSP 9225.Baird, D., 1979. ''Pneumatoarthrus'' Cope, 1870, not a dinosaur but a sea-turtle.
''Proceedings of the Academy of Natural Sciences'', Philadelphia, 129(4):71-81.

References

Protostegidae Cretaceous turtles of North America Prehistoric turtle genera Taxa named by Edward Drinker Cope Extinct turtles {{paleo-turtle-stub