Schistometopum thomense

Synonyms

The species has been described under the following synonyms:

• Siphonops thomensis — Bocage, 1873
• Siphonops brevirostris — Peters, 1874
• Dermophis brevirostris — Peters 1880
• Dermophis thomensis — Peters, 1880
• Schistometopum thomense — Parker, 1941
• Schistometopum ephele — Taylor, 1965
• Schistometopum brevirostris — Taylor, 1965
• Schistometopum brevirostre — Taylor, 1968

Phylogenetics

Interfamilial and intergeneric relationships of the São Tomé caecilian are well supported by analyses of mitochondrial (mtDNA) sequence data. At the genus level, Schistometopum was recovered as sister to Dermophis, a genus of caecilians found in South America; these two genera are paired in a clade. Within Schistometopum, Wilkinson et al. (2003) found that S. thomense is sister to S. gregorii (an East African species distributed in Kenya and Tanzania) which was also determined to be its lone congener. This congeneric grouping was later supported by sequence analyses of thirteen complete mitochondrial genomes from twelve caecilian species. However, species-level phylogenetic relationships of S. thomense have yet to be fully determined, given the recent discovery of Schistometopum ephele, a cryptic species on São Tomé Island. Available information on species-level relationships (inclusive of S. ephele) is limited to a single line of evidence that the common ancestor of S. thomense and S. ephele diverged from its sister species (S. gregorii) ~1 Ma. Further information is needed to fully understand phylogenetic relationships at the species level.

Zooming out to higher-level phylogenetic relationships, S. thomense was historically placed in the Caeciliidae, a highly unresolved grouping that was paraphyletic with respect to the Typhlonectidae and the Scolecomorphidae. This classification remained until 2011, when a nine-family level taxa (Rhinatrematidae, Ichthyophiidae, Scolecomorphidae, Herpelidae, Caeciliidae, Typhlonectidae, Indotyphlidae, Siphonopidae, and Dermophiidae) for caecilians that resolved the paraphyly of Caeciliidae and placed the genus Schistometopum in the Dermophiidae (Dermophis, Geotrypetes, Gymnopis, and Schistometopum), sister to Siphonopidae, was proposed. Subsequent studies on caecilians used this nine-family classification.

References

References

1. IUCN SSC Amphibian Specialist Group. (2020). "''Schistometopum thomense''".
2. [https://societyofbiology.blogspot.com/2012/02/species-of-week-cobra-bobo.html Species of the week: Cobra Bobo]
3. (2006). "Bergmann's rule and the terrestrial caecilian Schistometopum thomense (Amphibia: Gymnophiona: Caeciliidae)". Evolutionary Ecology Research.
4. "Schistometopum thomense". Amphibian Species of the World 6.0, an Online Reference.
5. (2003-12-01). "Phylogenetic relationships of African caecilians (Amphibia: Gymnophiona): Insights from mitochondrial rRNA gene sequences". African Journal of Herpetology.
6. (2014-08-29). "Population Genetics of the São Tomé Caecilian (Gymnophiona: Dermophiidae: Schistometopum thomense) Reveals Strong Geographic Structuring". PLOS ONE.
7. (2009-11-01). "A mitogenomic perspective on the phylogeny and biogeography of living caecilians (Amphibia: Gymnophiona)". Molecular Phylogenetics and Evolution.
8. (June 2021). "Speciation and secondary contact in a fossorial island endemic, the São Tomé caecilian". Molecular Ecology.
9. (2007-10-22). "Relative time scales reveal multiple origins of parallel disjunct distributions of African caecilian amphibians". Biology Letters.
10. Taylor, Edward Harrison. (1965). "New Asiatic and African caecilians with redescriptions of certain other species". The University of Kansas Science Bulletin.
11. (1998). "Revision of the African Caecilian Genus Schistometopum Parker (Amphibia: Gymnophiona: Caeciliidae)". Miscellaneous Publications of the Museum of Zoology University of Michigan.