''Glyptops'' 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
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 ...
on the basis of AMNH 6099, a partial shell from 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 ...
(
Tithonian
In the geological timescale, the Tithonian is the latest age (geology), age of the Late Jurassic Epoch and the uppermost stage (stratigraphy), stage of the Upper Jurassic Series. It spans the time between 149.2 ±0.7 annum, Ma and 143.1 ±0.6 (mi ...
) aged
Morrison Formation of
Colorado
Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas ...
. In 1890, a partial skull, YPM 1784 (described from
Como Bluff,
Wyoming
Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...
), was named ''Glyptops ornatus'' by
Othniel Charles Marsh. 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 ...
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 landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...
. ''Glyptops'' later became a
wastebasket taxon 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
In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application.
Zoology
In case of a ''nomen dubium,'' it may be impossible to determine whether a ...
'', 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
The Aptian is an age (geology), age in the geologic timescale or a stage (stratigraphy), stage in the stratigraphic column. It is a subdivision of the Early Cretaceous, Early or Lower Cretaceous epoch (geology), Epoch or series (stratigraphy), S ...
-early
Albian
The Albian is both an age (geology), age of the geologic timescale and a stage (stratigraphy), stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early Cretaceous, Early/Lower Cretaceous epoch (geology), Epoch/s ...
)
Arundel Formation of
Maryland
Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It borders the states of Virginia to its south, West Virginia to its west, Pennsylvania to its north, and Delaware to its east ...
. 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
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