pentameroid
/pɛnˈtamərɔɪd/Palaeontology
adjective
Of or relating to the extinct superfamily Pentameroidea or family Pentameridae of articulate brachiopods having roughly pentagonal shells, known from fossils of Ordovician to Devonian age.
noun
A pentameroid brachiopod.
Origin
Late 19th century; earliest use found in American Cyclopedia. From scientific Latin Pentamerus + -oid.