''Platycrinites'' are an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus of Paleozoic stalked

crinoid Crinoids are marine invertebrates that make up the class Crinoidea. Crinoids that remain attached to the sea floor by a stalk in their adult form are commonly called sea lilies, while the unstalked forms, called feather stars or comatulids, are ...

s belonging to the family Platycrinitidae. These stationary upper-level epifaunal suspension feeders lived during the

Devonian The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

and the

Carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ...

periods, from 376.1 to 259.0 Ma.

Species

*''Platycrinites crokeri'' Campbell and Bein 1971 *''Platycrinites ellesmerense'' Broadhead and Strimple 1977 *''Platycrinites halos'' Webster and Jell 1999 *''Platycrinites hemisphaericus'' (Meek & Worthen) *''Platycrinites nikondaense'' Broadhead and Strimple 1977 *''Platycrinites omanensis'' Webster and Sevastopulo 2007 *''Platycrinites testudo'' Campbell and Bein 1971 *''Platycrinites wachsmuthi'' Wanner 1916 *''Platycrinites wrighti'' Marez-Oyens 1940

Description

These moderate sized extinct crinoids had a columnar stem with a twisted pattern.Encyclopaedia britannica
/ref> On top of the stem was a

calyx CALYX, Inc. is a non-profit publisher of art and literature by women founded in 1976 based in Corvallis, Oregon. CALYX publishes both '' CALYX, A Journal of Art and Literature by Women'' twice a year and CALYX Books, which publishes one to three ...

with a number of feather-like arms.

Distribution

Fossils of this genus have been found in the

of Germany, in the

of Australia, Canada, China, Ireland, United Kingdom, United States. As well as in the

of Australia, Canada, Indonesia, Oman and United States.

References

Prehistoric crinoid genera Prehistoric echinoderms of North America Carboniferous crinoids Fossils of Georgia (U.S. state) Paleozoic life of Alberta Paleozoic life of Nunavut {{paleo-crinoidea-stub