The Calymenina (“KAH-lee-meh-NEE-nah”) suborder of these animals is characterized by having its suture end at the genal (“jee-nal”) angle. A set of structures found in these animals can be classified into holochroal (“HOE-loe-krole”), schizochroal (15[1])(“SKIT-soe-krole”), or abathochroal (“ah-BAH-thoe-krole”) subtypes. In 1999, a research group from the University of Manitoba discovered the largest one of these animals near Churchill measuring at 28 inches long; (15[1]-5[1])that animal is of the species Isotelus (“EYE-soe-tehl-uhs”) rex. These animals, (-5[1])which were the first to have evolved (*) compound eyes, (10[1])proliferated (10[1])by the end (10[1])of the (10[1])Terreneuvian (“TAYR-uh-NOO-vee-an”) series of the Cambrian (10[1])era. (-5[1])Due to their similar (-5[1])appearance, horseshoe crabs (10[4]-5[1])are often (10[2])erroneously (-5[1])stated (-5[1])to be (10[1])the closest (10[1])relative (10[1])to these (10[1])invertebrates. For 10 points, (10[1])name these extinct (10[1])marine (10[1])arthropods named for their “three-lobed” (10[1])body (10[2])organization. (10[1])■END■ (10[5])