Description

Our reconstruction is based on the finely preserved specimen of Mixopterus PMFP10 found at Ringerike in Oslo, Norway. It measures 80 cm in length.

Mixopterus is a medium-sized eurypterid characterized by spines on its first two appendages for capturing prey. Physically, Mixopterus was characterized by a robust exoskeleton with scattered semicircular tubercles or scales.

The prosoma (cephalothorax) was subquadrate, protruding anteriorly medially. The chelicerae (pincers next to the mouth) were small. The first two pairs of legs were highly developed, with long paired spines. The third and fourth legs were of more moderate size, with short spines. The mesosoma (preabdomen) was narrow with axial grooves, while the metasoma (postabdomen) was narrower. The telson was a curved spine.

Bibliography: Hanken, N.-M. Størmer, L. (1975): “The trail of a large Silurian eurypterid”. Ritchie, Alexander (1968-12-01). “Lanarkopterus dolichoschelus (Størmer) gen. nov., a mixopterid eurypterid from the Upper Silurian of the Lesmahagow and Hagshaw Hills inliers, Scotland”

Ateleaspis, the prey of Mixopterus in our reconstruction Ateleaspis is an extinct genus of primitive ostracoderm fish that lived from the Silurian (Wenlock) period to the Early Devonian. Like other ostracoderms, Ateleaspis had a head shield similar to that of Cephalaspis. Silurian species were found in Norway and Scotland, but have now also been found in Siberia from the Early Devonian period. Description Ateleaspis is possibly the most basal vertebrate with paired fins. Ateleaspis was a small fish (15–20 cm) and had a flat hull and a narrow trunk covered with brick-shaped scales.

Bibliographies consulted: Afanassieva, Olga Borisovna. The exoskeleton of Ungulaspis and Ateleaspis (Osteostraci, Agnatha) from the Lower Devonian of Severnaya Zemlya, Russia. OCLC 1228830520