''Iocrinus'' 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 ...
of
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 ...
(sea lilies and feather stars). It is an early
form
Form is the shape, visual appearance, or configuration of an object. In a wider sense, the form is the way something happens.
Form may also refer to:
*Form (document), a document (printed or electronic) with spaces in which to write or enter dat ...
of crinoid, from the
Ordovician
The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era, and the second of twelve periods of the Phanerozoic Eon (geology), Eon. The Ordovician spans 41.6 million years f ...
rock
Rock most often refers to:
* Rock (geology), a naturally occurring solid aggregate of minerals or mineraloids
* Rock music, a genre of popular music
Rock or Rocks may also refer to:
Places United Kingdom
* Rock, Caerphilly, a location in Wale ...
of
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 ...
,
England
England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...
, and
Gilwern Hill, Powys
Gilwern Hill is a hill about 3 mi / 5 km southeast of Llandrindod Wells in the county of Powys, Wales.
Geology
The hill is composed from a range of lower and middle Ordovician volcaniclastic rocks which form a part of the Builth Inlie ...
in
Wales
Wales ( ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by the Irish Sea to the north and west, England to the England–Wales border, east, the Bristol Channel to the south, and the Celtic ...
.
Selected species
* ''
Iocrinus brithdirensis''
* ''
Iocrinus crassus''
* ''
Iocrinus pauli''
* ''
Iocrinus shelvensis''
* ''
Iocrinus similis''
* ''
Iocrinus subcrassus''
* ''
Iocrinus trentonensis''
* ''
Iocrinus whitteryi''
References
Paleobiology Database entry''Iocrinus'' in the Ordovician of England and Wales* Stuart M. Kelly, ''Functional Morphology and Evolution of Iocrinus: An Ordovician Disparid Inadunate Crinoid'', Indiana University, 1978.
Iocrinidae
Ordovician crinoids
Ordovician echinoderms of Europe
Ordovician echinoderms of North America
Paleozoic life of Ontario
Verulam Formation
{{Paleo-crinoidea-stub