The Paleontology of the midwest

Echinoderms from North America

> Seastars | Echinoids | Crinoids | Other Echinoderms

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Delocrinus
Delocrinus
© 2004 Kansas Geological Survey

Astrodaspis coalingensis
Astrodaspis coalingensis
© 2004 UCMP

Amecystis laevis
Amecystis laevis
© 2006 Joe Koniecki

What are Echinoderms? Echinoderms, meaning “spiny-skinned,” include sand dollars, sea urchins, and sea stars, as well as less familiar creatures, such as sea cucumbers, crinoids, blastoids, and cystoids. This diverse group is entirely marine and is characterized by the presence of five-fold symmetry. Echinoderms have a specialized system of internal canals that circulates water through the body and services numerous, tiny appendages, called tube feet. They use their tube feet to move around or to capture food.

First known fossil occurrence: Cambrian.

Last known fossil occurrence: Quaternary. This group has living relatives.

Fossils through time:
Choose a time period to see what life was like:

Quaternary
Tertiary
Cretaceous
Jurassic
Triassic
Permian
Carboniferous
Devonian
Silurian
Ordovician
Cambrian
Precambrian