Genuine Elrathia Kinghi Trilobite Fossil 2 3/8" x 2 3/8"

Elrathia Kinghi Fossil Trilobite, found in Utah. You will receive the exact specimen pictured here. Measurement with Shale Matrix: 2 3/8" x 2 3/8" This specimen includes 2 trilobites measuring 5/8" x 1/4", 1/4" x 1/4", Great earth science teacher resource or fossil gift or collectible. Trilobites are a group of extinct marine arachnomorph arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period, and they flourished throughout the lower Paleozoic era before beginning a drawn-out decline to extinction when, during the Devonian, all trilobite orders except the Proetids died out. Trilobites disappeared in the mass extinction at the end of the Permian about 252 million years ago. The trilobites were among the most successful of all early animals, existing in oceans for almost 300 million years.