Laccosaurus

Laccosaurus is an extinct monotypic genus of rhinesuchid temnospondyl, the type species being Laccosaurus watsoni.

Laccosaurus Temporal range: Lopingian PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Order:	†Temnospondyli
Suborder:	†Stereospondyli
Family:	†Rhinesuchidae
Genus:	†Laccosaurus Haughton, 1925
Type species
†Laccosaurus watsoni Haughton, 1925

History of study

Laccosaurus watsoni was named by paleontologist Sidney H. Haughton in 1925 on the basis of a largely complete skull from the Dicynodon-Theriognathus subzone of the Daptocephalus Assemblage Zone in South Africa.^[1][2][3] This genus and/or species has sometimes been synonymized with Uranocentrodon,^[4][5][6] but this framework has not been adopted by recent workers.^[7][2][8] However, there is uncertainty related to the single referred specimen (BPI/1/4473); Eltink et al. (2019) consider this to belong to a different taxon, while Marsicano et al. (2017) considered it to belong to L. watsoni.

Anatomy

Marsicano et al. (2017) were the most recent to diagnose this taxon and list the following unique combination of characters: "well-developed sensory sulci, infra-orbital sulcus with a step/S- like flexure between the orbit and the naris; width of interpterygoid vacuity pair greater than 90% of their length; vomers with field of denticles in symmetrical raised patches medially to the choanae; straight transverse vomerine tooth row; quadrate condyles projected behind the tip of the tabular horns; parasphenoid plate subrectangular, longer than wide, with a flat ventral surface; well-developed ‘pockets’, close to each other, thus the cristae musculares converge in the midline."

References

• Paleontology portal

1. Haughton, Sidney H. (1925). "Investigations in South African Fossil Reptiles and Amphibia. Part 13. Descriptive Catalogue of the Amphibia of the Karroo System". Annals of the South African Museum. Annale van die Suid-Afrikaanse Museum. 22: 227–261. ISSN 0303-2515.
2. Marsicano, Claudia A.; Latimer, Elizabeth; Rubidge, Bruce; Smith, Roger M.H. (2017-05-29). "The Rhinesuchidae and early history of the Stereospondyli (Amphibia: Temnospondyli) at the end of the Palaeozoic". Zoological Journal of the Linnean Society. doi:10.1093/zoolinnean/zlw032. hdl:11336/105150. ISSN 0024-4082.
3. Viglietti, P.A. (2020-06-01). "Biostratigraphy of the Daptocephalus Assemblage Zone (Beaufort Group, Karoo Supergroup), South Africa". South African Journal of Geology. 123 (2): 191–206. doi:10.25131/sajg.123.0014. ISSN 1996-8590.
4. Sherwood, Romer, Alfred (1947). Review of the labyrinthodontia. OCLC 253748351.{{cite book}}: CS1 maint: multiple names: authors list (link)
5. Ochev, Vitaliĭ G. (1966). Systematics and phylogeny of capitosauroid labyrinthodonts (in Russian). Saratov: Saratov State University Press. pp. 1–181.
6. Schoch, Rainer R.; Milner, Andrew R. (2000). Handbuch der Paläoherpetologie Part 3B. Stereospondyli. Stuttgart: Verlag Dr. Friedrich Pfeil. pp. 1–106. ISBN 978-3-931516-26-0. OCLC 580976.
7. Damiani, Ross J. (2004). "Temnospondyls from the Beaufort Group (Karoo Basin) of South Africa and Their Biostratigraphy". Gondwana Research. 7 (1): 165–173. doi:10.1016/s1342-937x(05)70315-4. ISSN 1342-937X.
8. Eltink, Estevan; Schoch, Rainer R.; Langer, Max C. (2019-04-16). "Interrelationships, palaeobiogeography and early evolution of Stereospondylomorpha (Tetrapoda: Temnospondyli)". Journal of Iberian Geology. 45 (2): 251–267. doi:10.1007/s41513-019-00105-z. ISSN 1698-6180.