Flexicalymene Retrorsa Arnheim Formation Ohio
Trilobite Species: Flexicalymene Retrorsa
Matrix Formation: Arnheim 450 million years ago.
trilobite itself measures at: 1 x 3/4 matrix. 2 7/8 x 2 5/8.
Trilobites were an exclusively marine group of arthropods that appeared in the Cambrian Period and persisted throughout the Paleozoic, eventually becoming eztinct in the Permian Period. Most were small, bottom-dwelling organisms that fed on organic matter in sediment on the sea bottom. The body is divided in three segments: head (cephalon), middle (thorax), and tail (pygidium). Many species had large, compound eyes.