The Collaborative International Dictionary
Tentaculite
Tentaculite \Ten*tac"u*lite\, n. (Paleon.) Any one of numerous species of small, conical fossil shells found in Paleozoic rocks. They are supposed to be pteropods.
Wiktionary
tentaculite
n. (context paleontology English) Any of numerous species of small, conical shells found in Paleozoic rocks, fossils from the extinct genus (taxlink Tentaculites genus noshow=1).