Chasmataspis laurencii
| Chasmataspis laurencii | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Temporal occurrence | ||||||||||||
| Middle Ordovician | ||||||||||||
| 470 to 458.4 million years | ||||||||||||
| Locations | ||||||||||||
|
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name of the family | ||||||||||||
| Chasmataspididae | ||||||||||||
| Caster & Brooks , 1956 | ||||||||||||
| Scientific name of the genus | ||||||||||||
| Chasmataspis | ||||||||||||
| Caster & Brooks , 1956 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Chasmataspis laurencii | ||||||||||||
| Caster & Brooks , 1956 |
Chasmataspis laurencii is an extinct species from the order Chasmataspidida of the jaw-claw bearers (Chelicerata).
features
The prosomal dorsal shield is wider than it is long and ends in lateral spines. A clear edge is provided with small, rounded pits and is separated from the rest of the spinal cord by a narrow (0.2 mm) furrow with tiny tubercles . A relatively large pair of eyes are located on a slightly raised, heart-shaped eye mound in the center of the back shield. The preabdomen is fused into a single plate or shield, but with individual tergites still visible , and has jagged edges. On each of these tergites there is a pair of relatively large tubercles in the middle. The post-abdomen is elongated and slightly tapered and consists of 9 apparently ring-like, more or less rectangular segments with tubercles, similar to those of the prosoma and the preabdomen, with straight posterior and lateral margins. The telson is elongated and lance-shaped and has a rounded end.
Location
All specimens of this species were found in eastern Tennessee ( Sevier County ) in the Five Oaks Formation.
Systematics
Chasmataspis laurencii is the only member of the genus Chasmataspis and the monogeneric family Chasmataspididae. The first description was in 1956 by KE Caster and HK Brooks. The specific epithet honors the geologist Robert Abraham Laurence (1908–1984).
swell
literature
- Jason A. Dunlop, Lyall I. Anderson, Simon J. Braddy: A redescription of Chasmataspis laurencii Caster & Brooks, 1956 (Chelicerata: Chasmataspidida) from the Middle Ordovician of Tennessee, USA, with remarks on chasmataspid phylogeny . Transactions of the Royal Society of Edinburgh: Earth Sciences 94, 2004: 207-225. PDF; 7.04 MB
Individual evidence
- ↑ KE Caster, HK Brooks: New fossils from the Canadian Chazan (Ordovician) hiatus in Tennessee . Bulletins of American Palaeontology 36, 1956: 157-199.