Watsonulus and Semionotus elegans

Watsonulus eugnathoides (originally Watsonia Piveteau 1935; Olsen 1984; Early Triassic; 7cm skull length, 30cm long) is a traditional parasemionotid fish here instead related to the extant muskellunge, Esox, and the extant snakehead, Channa, another predatory freshwater bony fish. Note the large diamond opening between the nasals and frontals in dorsal view. The parietals are separated laterally by the postparietal. The teeth are extremely tiny. The pectoral fins are much larger than the pelvic fins.

Semionotus elegans (Agassiz 1843; Olsen and McCune 1991; Late Triassic to Early Jurassic; 30 cm) nests with Watsonulus iin the LRT, not with Semionotus bergeri , which nests at the base of the Actinista (coelacanths).

Agassiz L 1843. Recherches sur les poissons fossiles: 5 vols, with atlas (Neuchâtel).

Bean L B 2021. Revision of the Mesozoic freshwater fish clade Archaeomaenidae. Alcheringa: An Australasian Journal of Palaeontology. 45 (2): 217–259. .

Olsen PE 1984. The skull and pectoral girdle of the parasemionotid fish Watsonulus eugnathoides from the Early Triassic Sakamena Group of Madagascar, with comments on the relationships of the holostean fishes. Journal of Vertebrate Paleontology 4(3):481–499.

Olsen PE and McCune AR 1991 (online 2010). Morphology of the Semionotus elegans species group from the Early Jurassic part of the Newark Supergroup of eastern North America with comments on the Family Semionotidae (Neopterygii). Journal of Vertebrate Paleontology 11(3): 269–292.

Piveteau J 1930. C R Acad. Sci. Paris, 191

Piveteau J 1935. Palkontologie de Madagascar. XXI. Les Poissons du Trias infkrieur. Contribution 2 l'ktude des actinoptkrygiens. Annales de Pal6ontologie 23:8 1-1 80.

wiki/Watsonulus
wiki/Archaeomaenidae
wiki/Semiionotus