Symphysops
Symphysops is a genus of trilobites of average size, belonging to the Cyclopygidae family. It had a cosmopolitan distribution and lived from the Middle to the Upper Ordovician. It has been found in Canada, China, the Czech Republic, Iran, Ireland, Kazakhstan, Poland, Morocco, Spain, Scotland and Wales. The name Symphysops refers to the fused eyes, common to the species of this genus. Some species of the cyclopygid genera Cyclopyge and Pricyclopyge share this character, but Symphysops uniquely combines the merged eye with a frontal thorn on the head and the "lower eyelid".
Description
Symphysops is characterized by large eyes that merge at the front of the headshield to form what looks like a visor with at the back a wide free cheek. The remainder of the cephalon is filled by the glabella, which in most species extends into a forward pointing thorn at its frontal tip. The occipital ring cannot be distinguish from the rest of the glabella, which has two pair of transverse furrows, the rear pair distinct, and the frontal pair very shallow. The thorax consists of six segments, the frontal segment carrying backward directed pleural spines.Ecology
Symphysops has features typically associated with a pelagic lifestyle, among which very large eyes, compact thorax and indications of strong musculature. In some later cyclopygids, progressive enlargement resulted in the anterior fusion of their eyes. Given the weight of the dorsal exoskeleton, it is likely cyclopygids swam upside down, not unlike some extant crustaceans with pelagic lifestyles.Symphysops is often found in the company of other pelagic trilobites such as Cyclopyge, Degamella, Opipeuterella and Carolinites.
Species
S. armatus synonym Aeglina armataS. dejhaglensis Kolova, 1936S. mitrata synonym Aeglina mitrataS. sinensis Han, 1983S. spinifera Cooper & Kindle, 1936S. stevaninae López-Soriano & Corbacho, 2012S. subarmatus- * S. subarmatus subarmatus
- * S. subarmatus elongatus Kielan, 1959S. sulcatus synonym ''Aeglina sulcata''