Category
page 1Trilobite anatomy
thorax
The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of mammals and other tetrapod animals located between the neck and the abdomen.

pygidium
right|thumb|222px|Diagram showing the location of the Cephalon (arthropod head)|cephalon, [[thorax and pygidium of a trilobite.]]
The pygidium (: pygidia) is the posterior body part or shield of crustaceans and some other arthropods, such as insects and the extinct trilobites. In groups other than insects, it contains the anus and, in females, the ovipositor. It is composed of fused body segments, sometimes with a tail, and separated from thoracic segments by an articulation.
arthropod leg
locomotory appendage of arthropods
cephalon
the head section of an arthropod