''Uintacrinus'' ("crinoid from the Uinta Mountains") is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

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 nom ...

crinoid 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 are ...

s from the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

Kansas Kansas () is a state in the Midwestern United States. Its capital is Topeka, and its largest city is Wichita. Kansas is a landlocked state bordered by Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to th ...

. It was unusual among crinoids because it had no stalk, and probably floated above the seafloor. It lived in the

Western Interior Seaway The Western Interior Seaway (also called the Cretaceous Seaway, the Niobraran Sea, the North American Inland Sea, and the Western Interior Sea) was a large inland sea that split the continent of North America into two landmasses. The ancient sea ...

. This crinoid was a colonial animal with ten long arms each that it used to capture prey.Mike Everhart, (2004). http://www.oceansofkansas.com/Uintacrinus.html

Footnotes

Sources

* ''Fossils'' (Smithsonian Handbooks) by David Ward (Page 174) * "Notes on ''Uintacrinus socialis'' Grinnell" http://www.oceansofkansas.com/Uintacrinus.html

References

* Everhart, Mike "Notes on ''Uintacrinus socialis'' Grinnell" http://www.oceansofkansas.com/Uintacrinus.html * Uintacrinida Prehistoric crinoid genera Cretaceous animals of North America Prehistoric echinoderms of North America {{paleo-crinoidea-stub