A fossil crinoid of the genus Pentacrinus or family Pentacrinitidae, having a five-sided stalk and a calyx consisting of five plates, and known from remains of the Jurassic period.
Origin
Early 19th century. From scientific Latin Pentacrinus, genus name + -ite.
Definition of pentacrinite in US English:
pentacrinite
nounpɛnˈtakrɪnʌɪt
rare
A fossil crinoid of the genus Pentacrinus or family Pentacrinitidae, having a five-sided stalk and a calyx consisting of five plates, and known from remains of the Jurassic period.
Origin
Early 19th century. From scientific Latin Pentacrinus, genus name + -ite.