Corynexochida is an order of trilobite that lived from the Lower Cambrian to the Middle Devonian. Like many of the other trilobite orders, Corynexochida contains many species with widespread characteristics. The tips of the thoracic segments of many Corynexochida species are spine-like (though in some species they are flush with the sides and smooth). The thorax can have 2-12 segments (rarely more), but they more typically have 7-8.