Mixopterus

Mixopterus is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of Mixopterus have been discovered in deposits from Late Silurian age, and have been referred to several different species. Fossils have been recovered from two continents; Europe and North America. Mixopterus is the sole known representative of the eurypterid family Mixopteridae.''''

==Description== left|thumb|Life restoration of M. kiaeri. Mixopterus was a medium-sized predatory eurypterid. The largest species, M. simonsoni, reached lengths of 75 cm (29.5 in). It was characterised by a robust exoskeleton with scattered tubercles or semicircular scales. The prosoma (head) was subquadrate, protruding antemedially. The chelicerae (claws in front of the mouth) were small. The two first pairs of legs of Mixopterus (appendages II and III) were highly specialized and not used for walking, instead being highly developed with long paired spines. The two following pairs (appendages IV and V) were moderately sized and typically spiniferous walking legs. The last legs, (VI), form a pair of swimming legs characteristic of the Eurypterida.