Phylum Echinodermata

Holothuroidea (sea cucumbers)
mouth and anus at opposite ends (secondary
ossicles are imbedded within leathery skin
ossicles often reduced to little sclerites (typify certain families)
only in mouth region is a rigid series of plates (perioral ring)
ambulacra arranged in two sets parallel with the long axis (3 ventral, 2 dorsal)
few complete fossils: 2 Upper Jurassic (Solnhofen), 1 Lower Devonian Hunsrück
Ordovician?, since Early Devonian
Palaeocucumaria hunsrueckiana
Echinodermata – classification – Eleutherozoa – Holothuroidea
modified tube feet
for feeding