Productida

Productida

 

an extinct order of animals of the phylum Brachiopoda that lived from the Silurian to the Permian. The shell, which had a convex ventral valve and a flat or concave dorsal one, reached a length of 25 cm. The surface of the shell had hollow needles. The inside of the dorsal valve shows traces of attachment of long body processes—arms—that lacked special skeletal formations. Productida were attached to the sea bottom or lay on it. Their remains are valuable to stratigraphers in the study of Paleozoic deposits.

REFERENCE

Osnovy paleontologii: Mshanki, brakhiopody. Moscow, 1960. Page 221.