Pulmonoscorpius
| Pulmonoscorpius | |
|---|---|
| |
| Reconstruction of Pulmonoscorpius kirktonensis | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Subphylum: | Chelicerata |
| Class: | Arachnida |
| Order: | Scorpiones |
| Family: | †Centromachidae |
| Genus: | †Pulmonoscorpius Jeram, 1994 |
| Species: | †P. kirktonensis
|
| Binomial name | |
| †Pulmonoscorpius kirktonensis Jeram, 1994
| |
Pulmonoscorpius kirktonensis is an extinct species of scorpion[1] that lived during the Viséan age of the Carboniferous period during the Viséan and Serpukhovian, around 336.0 – 326.4 million years ago.[2]
Etymology
The name derives from "Latin pulmonis, a lung, and Greek skorpios, a scorpion"[2] The Latin suffix -ensis means "of or from a place."
Distribution
Its fossils were found in the East Kirkton Limestone at East Kirkton Quarry, West Lothian in Scotland. It dates to the Carboniferous.[3]
Description and taxonomy
The diet of Pulmonoscorpius is not known directly, but it is probable that it preyed on smaller arthropods, and small tetrapods.[4]
Most complete specimens were 13–280 mm (0.51–11.02 in) in length, while a large, fragmentary specimen is estimated to have been 700 mm (28 inches) long when alive. The only portions preserved were the outer portions of the cuticle, estimated to only be 15-18 μm thick in the largest specimen.[2]
Pulmonoscorpius is characterized by the presence of a long spur on each of the apophysis (extension of the coxa, the basalmost segment) of the 1st leg pair, 1st ventral abdominal plate of juveniles with median lobation, as well as an elongated sternum (ventral plate between the leg bases) with Y-shaped sulcus.[2] Unlike modern scorpion but similar to other basal counterparts, Pulmonoscorpius possess a pair of anterior-positioned median eyes and a pair of lateral eyes that between 40 and 60 lateral ocelli may be present in each of them, as well as a last (5th) metastomal segment with length did not exceed the preceding 4th metastomal segment.[2] The surface of prosomal carapace and 7 mesosomal tergites are relatively smooth in juvenile while tuberculated in larger individual.[2] The chelicerae and legs were noted be to be similar to those of extant scorpions, except the coxae and femurs (1st and 3rd segments) in legs 3 and 4 are less elongated, and the tibiae of these legs are about the same length as their femora.[2] The femur and patella (4th segment) of each pedipalp, as well as each metasomal segment possess ridges lined up by rows of tubercles.[2] The mesosoma possessed a bilobed and laterally elongated genital operculum (covering of gonopore), pectines (comb-like sensory appendages) with 150-160 narrow teeth,[2] as well as 3 ventral plates in juveniles and 4 in adults.[2] As with modern scorpions, four pairs of book lungs were present at the corresponding ventral plates.[2]
Aside from the type species, two other specimens were noted to possibly be distinct, one with "juvenile pedipalp fingers with 30% more setal follicles" than P. kirktonensis and one "lacking tuberculateventral carinae on vesicle of telson."[2]
References
- ^ Andrew J. Jeram (1998). "Phylogeny, classification and evolution of Silurian and Devonian scorpions". In Paul A. Selden (ed.). Proceedings of the 17th European Colloquium of Arachnology, Edinburgh 1997 (PDF). British Arachnological Society. pp. 17–31. ISBN 0-9500093-2-6. Archived from the original (PDF) on 2011-07-25.
- ^ a b c d e f g h i j k l Jeram, Andrew J. (1993). "Scorpions from the Viséan of East Kirkton, West Lothian, Scotland, with a revision of the infraorder Mesoscorpionina". Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 84 (3–4): 283–299. doi:10.1017/S0263593300006106. ISSN 1755-6910.
- ^ Dunlop, Penney et Jekel, « A summary list of fossil spiders and their relatives » (version 20.5), from World Spider Catalog, Natural History Museum of Bern, 2020.
- ^ Jennifer A. Clack (2002). "East Kirkton and the roots of the modern family tree". Gaining Ground: the Origin and Evolution of Tetrapods. Life of the past. Indiana University Press. pp. 212–233. ISBN 978-0-253-34054-2.