''Platyceras'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

of extinct

Paleozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ' ...

sea snails, marine gastropod

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is es ...

s in the family

Platyceratidae Platyceratidae is an extinct family of Paleozoic sea snails, marine gastropod mollusks. This family may belong in the Patellogastropoda or the Neritimorpha. Platyceratids are known for the complex symbiotic relationships they had with cri ...

. This genus is known from the

Silurian The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago (Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozoi ...

to the

Middle Triassic In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided in chronostratigraphy. The Middle Triassic spans the time between Ma ...

periods and especially abundant in the

Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, w ...

and Carboniferous.Paleobiology Database
''Platyceras''
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cre ...

.org It is the type genus of the family Platyceratidae.

Description

''Platyceras'' has a distinctive, curved conical shape that is easily recognized. The cap-like shell is high and broad anteriorly. The posterior portion of the shell, at the apex, is usually slightly coiled in an asymmetrical fashion. Frequently, the front portions of the shells are broken, though the posterior sections are relatively well preserved. ''Platyceras'' is particularly abundant in

deposits (359 million to 416 million years old). ''Platyceras'' and other platyceratid gastropods are known for the complex symbiotic relationships they had with

crinoids Crinoids are marine animals that make up the class Crinoidea. Crinoids that are attached to the sea bottom by a stalk in their adult form are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, which ar ...

.Baumiller T. K. (2003). "Evaluating the interaction between platyceratid gastropods and crinoids; a cost-benefit approach". ''

Palaeogeography, Palaeoclimatology, Palaeoecology ''Palaeogeography, Palaeoclimatology, Palaeoecology'' ("''Palaeo3''") is a peer-reviewed scientific journal publishing multidisciplinary studies and comprehensive reviews in the field of palaeoenvironmental geology. The journal is edited by T. J ...

'' 201(3-4): 199-209. .

Distribution

Fossils of ''Platyceras'' have been found all over the world, among others in the Silurian

Bertie Formation The Bertie Group or Bertie Limestone, also referred to as the Bertie Dolomite and the Bertie Formation, is an upper Silurian (Pridoli, or Cayugan and Ulsterian age in the local chronologies) geologic group and Lagerstätte in southern Ontario ...

of Ontario and New York and the Devonian

Floresta Formation The Floresta Formation ( es, Formación Floresta, Df) is a geological formation of the Altiplano Cundiboyacense in the Eastern Ranges of the Colombian Andes. The sequence of siltstones, shales, coquinas and sandstone beds dates to the Devonian ...

of Boyacá, Colombia.Mojica & Villarroel, 1984, pp.65-69

References

* T. A. Conrad. 1840. ''Third annual report on the palaeontological department of the survey.'' New York Geological Survey, Annual Report 4(1):199-207

Bibliography

* {{Taxonbar, from=Q2689745 Platyceratidae Silurian first appearances Triassic extinctions Prehistoric molluscs of North America Devonian animals of South America Devonian Colombia Fossils of Colombia Floresta Formation Paleozoic life of Ontario Bertie Formation Paleozoic life of Manitoba Paleozoic life of New Brunswick Paleozoic life of the Northwest Territories Paleozoic life of Nova Scotia Paleozoic life of Nunavut Paleozoic life of Quebec Fossil taxa described in 1840