''Pentremites'' is an extinct

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

blastoid Blastoids (class Blastoidea) are an extinct type of stemmed echinoderm, often referred to as sea buds. They first appear, along with many other echinoderm classes, in the Ordovician period, and reached their greatest diversity in the Mississi ...

echinoderm An echinoderm () is any animal of the phylum Echinodermata (), which includes starfish, brittle stars, sea urchins, sand dollars and sea cucumbers, as well as the sessile sea lilies or "stone lilies". While bilaterally symmetrical as ...

belonging to the family Pentremitidae.

Description

These stalked echinoderms averaged a height of about but occasionally ranged up to about 3 times that size. They, like other blastoids, superficially resemble their distant relatives, the crinoids or ''sea lilies'', having a near-identical, planktivorous lifestyle living on the sea floor attached by a stalk. As with all other blastoids, species of ''Pentremites'' trapped food floating in the currents by means of tentacle-like appendages.Museum of Victoria
/ref> ''Pentremites'' species lived in the early to middle

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 ...

, from 360.7 to 314.6 Ma. Its

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

s are known from

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

References

* ''Fossils'' (Smithsonian Handbooks) by David Ward (Page 190) Blastozoa genera Carboniferous echinoderms of North America Fossils of Georgia (U.S. state) Paleozoic life of Alberta Paleozoic life of the Northwest Territories Paleozoic life of Yukon {{paleo-echinoderm-stub