Palaeospinax is an extinct genus of synechodontiform cartilaginous fish. Although several species have been described, the genus is considered nomen dubium because the type-specimen of the type species, Palaeospinax priscus, from the Late Triassic-Early Jurassic of Europe lacks appropriate diagnostic characters to define the genus.[5]
Maisey, J. G. (1977). "The fossil selachian fishes Palaeospinax Egerton, 1872 and Nemacanthus Agassiz, 1837". Zoological Journal of the Linnean Society. 60 (3): 259–273. doi:10.1111/j.1096-3642.1977.tb01029.x.