palaechinoid
/palɪˈkʌɪnɔɪd/ /peɪlɪˈkʌɪnɔɪd/ /palˈɛkɪnɔɪd/(also palaeechinoid) Palaeontology
noun
Originally: an extinct echinoid (sea urchin) belonging to the former subclass Palaechinoidea, comprising all or most Palaeozoic echinoids, typically having more than two series of interambulacral plates. Now usually: a member of a more restricted group of Palaeozoic echinoids (sometimes classified as an order Palaechinoida) including the genus Palaechinus.
Origin
Mid 19th century; earliest use found in James Dana (1813–1895), geologist, zoologist, and teacher. From scientific Latin Palaechinoidea, subclass name from palaeo- + Echinoidea, class name, with coalescence of the vowels. With later use compare scientific Latin Palechinus, Palaechinus, Palaeechinus, genus name.