''Glyptops'' (Greek for "grooved face") is an extinct genus of pleurosternid freshwater turtle known from the Late Jurassic of North America.

Taxonomy

The type species, ''Glyptops plicatulus'', was first described as ''Compsemys plicatulus'' by Edward Drinker Cope on the basis of AMNH 6099, a partial shell from the

Late Jurassic The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987. In European lithostratigraphy, the name ...

( Tithonian) aged Morrison Formation of

Colorado Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...

. In 1890, a partial skull, YPM 1784 (described from

Como Bluff Como Bluff is a long ridge extending east–west, located between the towns of Rock River and Medicine Bow, Wyoming. The ridge is an anticline, formed as a result of compressional geological folding. Three geological formations, the Sundance, th ...

Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the s ...

), was named ''Glyptops ornatus'' by

Othniel Charles Marsh Othniel Charles Marsh (October 29, 1831 – March 18, 1899) was an American professor of Paleontology in Yale College and President of the National Academy of Sciences. He was one of the preeminent scientists in the field of paleontology. Among ...

. Later,

Oliver Perry Hay Oliver Perry Hay (May 22, 1846 – November 2, 1930) was an American herpetologist, ichthyologist, and paleontologist. Hay was born in Jefferson County, Indiana, to Robert and Margaret Hay. In 1870, Hay graduated with a bachelor of arts from Eu ...

recognized ''Compsemys plicatulus'' and ''Glyptops ornatus'' as being from the same species, hence the new combination ''G. plicatulus''. Another Morrison species of ''Glyptops'', ''G. utahensis'', was described from a complete shell (CM 3412) found at Dinosaur National Monument in

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

. ''Glyptops'' later became a

wastebasket taxon Wastebasket taxon (also called a wastebin taxon, dustbin taxon or catch-all taxon) is a term used by some taxonomists to refer to a taxon that has the sole purpose of classifying organisms that do not fit anywhere else. They are typically defined ...

to refer to isolated shell fragments with a finely sculpted surface texture. The type of ''Glyptops plicatulus'' was later judged to be a '' nomen dubium'', due to it lacking any diagnostic characters, and ''Glyptops ornatus'' was made to be the only valid species. The species ''Glytops caelatus'' Hay, 1908 was described from the middle Cretaceous (late Aptian-early

Albian The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous Epoch/ Series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± 0 ...

)

Arundel Formation The Arundel Formation, also known as the Arundel Clay, is a clay-rich sedimentary rock formation, within the Potomac Group, found in Maryland of the United States of America. It is of Aptian age (Lower Cretaceous). This rock unit had been econ ...

Maryland Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to ...

. However, it was later dismissed as a ''nomen dubium'' based on non-diagnostic remains.E. S. Gaffney. 1979. The Jurassic turtles of North America. Bulletin of the American Museum of Natural History 162(3):95-135

Description

The skull of ''Glyptops ornatus'' exhibit adaptions likely for

suction feeding Aquatic feeding mechanisms face a special difficulty as compared to feeding on land, because the density of water is about the same as that of the prey, so the prey tends to be pushed away when the mouth is closed. This problem was first identifi ...

References

''Glyptops''
at The Paleobiology Database Pleurosternidae Prehistoric turtle genera Tithonian genera Late Jurassic turtles Late Jurassic reptiles of North America Morrison fauna Fossil taxa described in 1890 Taxa named by Othniel Charles Marsh {{paleo-turtle-stub