Chasmataspis

Chasmataspis is a genus of chasmataspidid, a group of extinct aquatic chelicerate arthropods. It was found in the Early Ordovician deposits of Tennessee, United States.

Morphology

Just like other chasmataspidids, the body of Chasmataspis compose of a prosoma and a 13-segmented opisthosoma, with the latter subdivided into a 4-segmented preabdomen and a 9-segmented postabdomen. Dorsal to the carapace were pairs of ridges, lateral eyes and median ocelli. Chasmataspis characterized by a semicircular carapace with pointed genal spines and preabdomen with fused body segments. Rows of tubercles and spines run through the axial and lateral regions of opisthosoma. The body terminated with a spine-like telson.
There is no body fossils of Chasmataspis with unambiguous appendages being discovered. The only evidence were 2 specimens of disarticulated, claw-bearing appendages discovered from the same stratum which may represent the prosomal appendage of Chasmastaspis.