Trilobita
/ˌtrʌɪlə(ʊ)ˈbʌɪtə/ /ˌtrɪlə(ʊ)ˈbʌɪtə/Palaeontology
noun
With plural (or occasionally singular) concord: a large group of extinct multi-legged arthropods that occurred abundantly in Palaeozoic seas, typically having a flattened oval body with a solid head section (cephalon) with antennae and compound eyes, a flexible segmented thorax, and a solid tail section (pygidium), all of which are divided into three longitudinal lobes. Also treated as plural: animals of this group (collectively or individually); trilobites.
- Although considered to be a class, subphylum, or phylum (formerly an order) of arthropods, the relationship of the Trilobita to other arthropod groups is unclear. They are now sometimes regarded as a stem group ancestral to both the chelicerates and the crustaceans..
Origin
Mid 19th century; earliest use found in Reports of the British Association for the Advancement of Science. From scientific Latin Trilobita from German Trilobit + -a.