| Stylonurella Temporal range:
| |
|---|---|
| |
| Fossil illustration of Stylonurella spinipes | |
Scientific classification 
| |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Subphylum: | Chelicerata |
| Order: | †Eurypterida |
| Superfamily: | †Stylonuroidea |
| Family: | †Stylonurellidae Lamsdell, 2025 |
| Genus: | †Stylonurella Kjellesvig-Waering, 1966 |
| Species: | †S. spinipes
|
| Binomial name | |
| †Stylonurella spinipes Page, 1859
| |
Stylonurella is a genus of prehistoric eurypterid.1 It is the only genus classified in the Stylonurellidae2 family and contains a single valid species, S. spinipes from the Silurian of Kip Burn, Scotland.2
Description
Stylonurella was a small stylonuroid, possessing a subquadrate prosoma with approximately the same length as width. The midsection was slightly constricted and the eyes were parallel and anteriorly located in the anterior half of the carapace. The metastoma and first two appendages are unknown, the third and fourth prosomal legs are very short and the last two walking legs are very long. The metasoma is very narrow.3
Classification
Though one of the earliest described stylonurines, described shortly after the description of Stylonurus itself, it has no close relations to that genus. Indeed, there are numerous and apparent differences. For instance, the eyes of Stylonurus are located on the posterior half of the carapace and those of Stylonurella are on the anterior half.3
Species
Stylonurella contains one valid species,2 with other named species now seen as invalid or as part of other genera.
- Stylonurella spinipes Page, 1859 - Kip Burn, Scotland (Silurian)
Invalid or reassigned species are listed below:
- "Stylonurella" arnoldi Ehlers, 1935 - Pennsylvania, USA (Devonian), nomen dubium.2
- "Stylonurella" beecheri Hall, 1884 - Pennsylvania, USA (Devonian), nomen dubium.2
- "Stylonurella" logani Woodward, 1872 - Kip Burn, Scotland (Silurian), synonym of S. spinipes.4
- "Stylonurella" modestus Clarke & Ruedemann, 1912 - New York, USA (Ordovician), a pseudofossil.4
- "Stylonurella" otisius3 Clarke, 1907 - Eastern USA (Silurian), reclassified as a species of Clarkeipterus.4
- "Stylonurella" ruedemanni3 Størmer, 1934 - Ringerike, Norway (Silurian), reclassified as a species of Kiaeropterus.4
References
References
- Lamsdell, J. C.; Braddy, S. J.; Tetlie, O. E. (2010). "The systematics and phylogeny of the Stylonurina (Arthropoda: Chelicerata: Eurypterida)". Journal of Systematic Palaeontology. 8: 49. doi:10.1080/14772011003603564.
- Lamsdell, James C. (2025). "Codex Eurypterida: A Revised Taxonomy Based on Concordant Parsimony and Bayesian Phylogenetic Analyses". Bulletin of the American Museum of Natural History. 2025 (473): 60–68. doi:10.1206/0003-0090.473.1.1.
- A revision of the families and genera of the Stylonuracea (Eurypterida)
- Dunlop, J. A., Penney, D. & Jekel, D. 2015. A summary list of fossil spiders and their relatives. In World Spider Catalog. Natural History Museum Bern, online at http://wsc.nmbe.ch , version 16.0 http://www.wsc.nmbe.ch/resources/fossils/Fossils16.0.pdf (PDF).