Description
Dinotocrinus Crinoid
- Species:Â Dinotocrinus compactus
- Mississippian Age
- Monteagle Formation
- Madison County, Alabama
- This ELUSIVE Specimen measures 1.26″ long.
- MORE Crinoid Fossils for Sale
This is a NEWÂ a new fossil inadunate crinoid genus.
WHAT ARE CRINOIDS?
Crinoids are marine animals that make up the class Crinoidea of the echinoderms (phylum Echinodermata). Crinoidea comes from the Greek word krinon, “a lily”, and eidos, “form”. They live both in shallow water and in depths as great as 6,000 metres (20,000 ft). Sea lilies refer to the crinoids which, in their adult form, are attached to the sea bottom by a stalk. Feather stars or comatulids refer to the unstalked forms.Â
The basic body form of a crinoid is a stem (not present in adult feather stars) and a crown consisting of a cup-like central body known as the theca, and a set of five rays or arms, usually branched and feathery. The mouth and anus are both located on the upper side of the theca, making the dorsal (upper) surface the oral surface, unlike in the other echinoderm groups such as the sea urchins, starfish and brittle stars where the mouth is on the underside.