Lethiscus
Lethiscus Temporal range: Early Carboniferous
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Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Sarcopterygii |
Clade: | Tetrapodomorpha |
Order: | †Aistopoda |
Family: | †Lethiscidae Wellstead, 1982 |
Genus: | †Lethiscus Wellstead, 1982 |
Species: | †L. stocki
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Binomial name | |
†Lethiscus stocki Wellstead, 1982
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Lethiscus is the earliest known representative of the
Lethiscus is known from only a single specimen from the
The skull is specialised and light, very like that of
There is no trace of limbs. However, unlike later members of the aïstopod lineage, the vertebrae still possess intercentra, and the pleurocentra are large.
Lethiscus is the only representative of the family Lethiscidae. Owing to its early date, it has since its discovery been considered ancestral to later aïstopods, and more recent cladistic research (Anderson et al. 2003) confirms its position as the most basal (primitive) aistopod. A 2017 cladistic analysis incorporated new data on Lethiscus found all aïstopods, including Lethiscus, to be stem-tetrapods, rendering Lepospondyli polyphyletic.[1]
References
- Anderson, Jason S.; Carroll, Robert L. & Rowe, Timothy B. (2003). "New information on Lethiscus stocki (Tetrapoda: Lepospondyli: Aistopoda) from high-resolution computed tomography and a phylogenetic analysis of Aistopoda". Can. J. Earth Sci. 40 (8): 1071–1083. ]
- Carroll, R.L (1988), Vertebrate Paleontology and Evolution, WH Freeman & Co. pp. 176–7
- Wellstead, C.F. (1982). "A Lower Carboniferous aïstopod amphibian from Scotland". Palaeontology. 25: 193–208.