Chasmataspis
Extinct genus of arthropods
From Wikipedia, the free encyclopedia
Chasmataspis is a genus of chasmataspidid, a group of extinct aquatic chelicerate arthropods.[1][2] It was found in the Early Ordovician deposits of Tennessee, United States.[3]
| Chasmataspis Temporal range: | |
|---|---|
| |
| Holotype specimen | |
 | |
| Life reconstruction of C. laurencii | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Subphylum: | Chelicerata |
| Clade: | Dekatriata |
| Order: | †Chasmataspidida |
| Family: | †Chasmataspididae Caster & Brooks, 1956 |
| Genus: | †Chasmataspis Caster & Brooks, 1956 |
| Type species | |
| †Chasmataspis laurencii Caster & Brooks, 1999 | |
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.[4] Dorsal to the carapace were pairs of ridges, lateral eyes and median ocelli.[4] Chasmataspis characterized by a semicircular carapace (prosomal dorsal shield) with pointed genal spines and preabdomen with fused body segments.[4] Rows of tubercles and spines run through the axial and lateral regions of opisthosoma.[4] The body terminated with a spine-like telson.[4]
There is no body fossils of Chasmataspis with unambiguous appendages being discovered.[4] The only evidence were 2 specimens of disarticulated, claw-bearing appendages discovered from the same stratum which may represent the prosomal appendage (possibly appendage VI[3]) of Chasmastaspis.[4]
