The Mixopteridae are a family of eurypterids, an extinct group of cheliceratearthropods commonly known as "sea scorpions". The family is one of two families contained in the superfamily Carcinosomatoidea (along with Carcinosomatidae), which in turn is one of the superfamilies classified as part of the suborder Eurypterina. However, according to a 2024 paper this family may be paraphyletic, containing modern scorpions.[1]
Description
Mixopterids were characterized by large exoskeletons with scattered tubercles or semicircular scales. The prosoma (head) was subquadrate, protruding antemedially. The chelicerae (claws in front of the mouth) were small. The first two pairs of walking legs were strongly developed, with long paired spines. The third and fourth walking legs were moderately sized, with short spines. The preabdomen, the front portion of the body, was narrow with axial furrows, while the postabdomen was narrow. The telson was a curved spine.[2]
^Braddy, Simon J. (14 September 2024). "Carcinosomatoid eurypterid palaeoecology and phylogeny: ichnology and palaeocommunities". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 312 (2): 167–181. doi:10.1127/njgpa/2024/1206.
^ Størmer, L 1955. Merostomata. Treatise on Invertebrate Paleontology, Part P Arthropoda 2, Chelicerata, P34-P35.