Echinothurioida (subclass Euechinoidea, superorder Diadematacea) An order of regular echinoids that have flexible tests and compound ambulacral plates bearing three pairs of pores. The tubercles are non-crenulate. At the present day there are many abyssal forms. They first appeared in the Upper Jurassic.
More From encyclopedia.com
Maxilla , max·il·la / makˈsilə/ • n. (pl. max·il·lae / makˈsilē; -ˈsilˌī/ ) Anat. & Zool. the jaw or jawbone, specifically the upper jaw in most vertebrates. I… labrum , labrum 1. In Echinozoa, a lip-like projection of the peristome. 2. A broad piece of cuticle which forms the upper ‘lip’ in an insect. The labrum arti… Euechinoidea , Euechinoidea (class Echinoidea) Sub-class of sea-urchins in which the normally rigid test is composed of five ambulacra and five interambulacra, each… Painter, Eleanor (1890–1947) , pair / pe(ə)r/ • n. a set of two things used together or regarded as a unit: a pair of gloves. ∎ an article or object consisting of two joined or cor… Teddy Bear , Background Most people born in this century have probably encountered teddy bears during their lives, for the teddy bear was developed around the tur… Upper , up·per1 / ˈəpər/ • adj. 1. situated above another part: his upper arm the upper atmosphere. ∎ higher in position or status: the upper end of the soci…
About this article
Updated About encyclopedia.com content Print Article
You Might Also Like