trilobite

Etymology

tri- + lobe + -ite

noun

1. An extinct arthropod of the class Trilobita, whose body had three large lobes.
   When you look at a Precambrian trilobite in the lobby of a New York bank, it is difficult to speculate about its primeval environment. 1981, William Irwin Thompson, The Time Falling Bodies Take to Light: Mythology, Sexuality and the Origins of Culture, London: Rider/Hutchinson & Co., page 209