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bi·la·te·ri·an | \ ˌbī-lə-ˈtir-ē-ən 
\
\ plural bilaterians
Definition of bilaterian
biology
: an animal having bilateral symmetry Scientists refer to animals, including humans, with this two-sided symmetry as bilaterians.— Carl Zimmer, New York Times, 21 June 2005 Comb jellies and cnidarians branched off before bilaterians diversified into the variety of animal groups known today, and they are considered relatively “simple” organisms.— Elizabeth Pennisi, Science, 6 July 2007
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The first known use of bilaterian was in 1983
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