D defs.my
Entry 1 sense Webster, 1913

Pentamerus

· Pen·tam·e·rus · IPA
01 n. A genus of extinct Paleozoic brachiopods, often very abundant in the Upper Silurian.
  1. 1.
    A genus of extinct Paleozoic brachiopods, often very abundant in the Upper Silurian.(Paleon.)
Phrases & compounds
Pentamerus limestone — a Silurian limestone composed largely of the shells of Pentamerus.