Powichthys, Uranolophus and Janusiscus

Powichthys thorsteinssoni (Jessen 1975; Clément and Janvier 2004; Early Devonian; est. 30cm in length) was originally and correctly considered a member of the Dipnomorpha with internal nares within the tooth rowOften compared to Youngolepis, it is not closely related.

Uranolophus wyomingensis (Denison 1968; FMNJ PF 3805, 3792; Early Devonian) is a large, flat-head lungfish without a large vomerine tooth plate. Several cranial bones are broken up. The nasal was transverse. The lateral sides of the skull, premaxilla and maxilla have not been described.

Janusiscus schultzei (Giles et al. 2015; Early Devonian, 415 mya) was considered a possible ancestor to Chondrichthyes (sharks, etc.) or Osteichthyes (bony fish, etc.) or both. Here tiny Janusiscus nests with coeval and much, much larger Uranolophus. Both are in the lungfish clade, far from the ancestry of Chondrichtheys and Osteichthys.

Clement G and Janvier P 2004. Powichthys spitsbergensis sp. nov., a member of the Dipnomorpha (Sarcopterygii, lobe-finned fishes) from the Lower Devonian of Spitsbergen, with remarks on basal dipnomorph anatomy. Fossils and Strata, No. 50, pp. 92–112. France. ISSN 0300-9491.

Denison RH 1968. Early Devonian lungfishes from Wyoming, Utah and Idaho. Fieldiana, Geology 17:353–413.

Giles S, Friedman M and Brazeau MD 2015. Osteichthyan-like conditions in an Early Devonian stem gnathostome. Nature 520(7545):82–85.

Jessen HL 1975. A new choanate fish, Powichthys thorsteinssoni n.g. n.sp., from the early Lower Devonian of the Canadian Arctic Archipelago. Colloques internationaux du Centre National de la Recherche Scientifique, 218: 213–222.

wiki/Janusiscus
wiki/Uranolophus
wiki/Powichthys