''Pleurocystites'' (meaning ''rib bag'' or ''side bladder'') is a

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 ...

rhombifera The Eocrinoidea were an extinct class of echinoderms that lived between the Early Cambrian and Late Silurian periods. They are the earliest known group of stalked, brachiole-bearing echinoderms, and were the most common echinoderms during the Cam ...

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 ...

cystoid Cystoidea was defined as a class of extinct paleozoic blastozoan echinoderms established to encompass stalked taxa that were neither crinoids nor blastoids. It was shown to be polyphyletic in the late 1960s but continues to be used even in recen ...

) that lived in the

Late Ordovician The Late Ordovician is the third and final epoch of the Ordovician period, lasting million years and spanning from around 458.2 to 443.1 million years ago. The rocks associated with this epoch are referred to as the Upper Ordovician Series. At ...

. 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

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

and

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 ...

. ''Pleurocystites'' grew to a height of 2 centimeters (3/4 of an inch) and fed on

plankton Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...

Sources

* ''Fossils'' (Smithsonian Handbooks) by David Ward (Page 191) * Parker, Steve. Dinosaurus: the complete guide to dinosaurs. Firefly Books Inc, 2003. Pg. 75

External links

''Pleurocystites''
in the

Paleobiology Database The Paleobiology Database (PBDB) is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms. History The Paleobiology Database originated in the NCEAS-funded Phanerozoic Marine Pale ...

Rhombifera Ordovician echinoderms of Europe Ordovician echinoderms of North America Late Ordovician first appearances Late Ordovician extinctions Paleozoic life of Ontario Paleozoic life of Quebec {{paleo-echinoderm-stub