Chasmataspidida
| Chasmataspidida | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Live reconstruction of Dvulikiaspis menneri |
||||||||||
| Temporal occurrence | ||||||||||
| upper Cambrian to middle Devonian | ||||||||||
| 497 to 382.7 million years | ||||||||||
| Locations | ||||||||||
| Systematics | ||||||||||
|
||||||||||
| Scientific name | ||||||||||
| Chasmataspidida | ||||||||||
| Caster & Brooks , 1956 |
Chasmataspidida is an extinct order within the jaw-claw carriers (Chelicerata).
features
Chasmataspidida are true jawbones with a short, wide sclerite (1st opisthosomal segment), followed by a three-segmented preabdoma (segments 2–4) and a nine-segmented postabdoma (segments 5–13).
Locations
Species of the order Chasmataspidida have been found in North America ( Tennessee ), Europe ( Germany and Scotland ), and Russia.
Systematics
Some authors do not assign the Chasmataspidida to a class because the monophyly of the merostomata is questionable and the basic relationships within the Euchelicerata are controversial. Chasmataspididas share many similarities with Xiphosura (swordtails) and Eurypterida (sea scorpions) and are therefore separated from the Xiphosura by Anderson & Seldon in 1997. The superorder Chasmataspidiformii established by Starabogatov corresponds to the order Chasmataspidida and the order Chasmataspidiformes to the family Chasmataspididae , as well as the superfamily Chasmataspidacea established by Bergström. A more recent synonym of the order is Diploaspidida Simonetta & Delle Cave, 1978 .
There are currently two families with seven species in six genera:
- Chasmataspididae Caster & Brooks, 1956
-
Chasmataspis Caster & Brooks, 1956
- Chasmataspis laurencii Caster & Brooks, 1956
-
Chasmataspis Caster & Brooks, 1956
-
Diploaspididae Størmer, 1972
(= Heteroaspididae Størmer, 1972)-
Achanarraspis Anderson, Dunlop & Trewin, 2000
- Achanarraspis reedi Anderson, Dunlop & Trewin, 2000
-
Diploaspis Størmer, 1972
(= Heteroaspis Størmer, 1972)-
Diploaspis casteri Størmer, 1972
(= Heteroaspis novojilovi Størmer, 1972) - Diploaspis muelleri Poschmann, Anderson & Dunlop, 2005
-
Diploaspis casteri Størmer, 1972
-
Forfarella Dunlop, Anderson & Braddy, 1999
- Forfarella Mitchelli Dunlop, Anderson & Braddy, 1999
-
Loganamaraspis Tetlie & Braddy, 2004
- Loganamaraspis dunlopi Tetlie & Braddy, 2004
-
Octoberaspis Dunlop, 2002
- Octoberaspis ushakovi Dunlop, 2002
-
Achanarraspis Anderson, Dunlop & Trewin, 2000
It is still unclear whether the Eurypterus stoermeri Novojilov from Siberia , 1959, is possibly a representative of Chasmataspidida.
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
Individual evidence
- ↑ LI Anderson, PA Selden: Opisthosomal fusion and phylogeny of Palaeozoic Xiphosura . Lethaia 30, 1997: 19-31.
- ^ YI Starobogatov: The systematics and phylogeny of the lower chelicerates (a morphological analysis of the Paleozoic groups) . Paleontologicheskii Zhurnal 1, 1990: 4-17.
- ↑ J. Bergström: Functional morphology and evolution of xiphosurids . Fossils and Strata 4, 1975: 291-305.
- ^ OE Tetlie, SJ Braddy: The first Silurian chasmataspid, Loganamaraspis dunlopi gen. Et sp. nov. (Chelicerata: Chasmataspidida) from Lesmahagow, Scotland, and its implications for eurypterid phylogeny . Transactions of the Royal Society of Edinburgh: Earth Sciences 94, 2004: 227-234.