hōˌlektəˈpīnə noun plural
Usage: capitalized
Etymology: New Latin, from Holectypus, genus of sea urchins (from hol- + Greek ektypos worked in relief) + -ina
: a suborder of extinct sea urchins (order Exocycloida) having a central peristome, an excentric periproct, an Aristotle's lantern, and nonpetaloid ambulacra and found in Jurassic, Cretaceous, and Eocene strata