Contribution to the knowledge of the genus Pygocephalus Huxley, 1857: morphology and taxonomy

Abstract

-A morphological revision of the type species of the genus Pygocephalus Huxley, P. cooperi Huxley, brought out not only its redefi nition but also the emend of the diagnosis of Pygocephalus and the family Pygocephalidae. Previous works about this genus and related taxa are discussed, as well as the problem involved in the reconstruction of fossil species of Eumalacostraca based on isolate parts.

New species of Pygocephalomorpha (Crustacea) from the Irati Formation, Paraná Basin, RS, Southern Brazil

“…This fact might have led to overestimation of the number of species or led to the misinterpretation of certain taxa, positioning in the same group crustaceans that might not be directly related. A recent review of the genus Pygocephalus Huxley, 1857 exemplifies the problem by determining that one of the original figured specimens is the result of an assemblage of isolated pieces of two individuals, the carapace of one and the pleon of another, preserved in such a way to look like a single specimen (Pinto & Würdig, 2014). The work also states that more than one species of malacostracan crustacean could be present in the same location, even in the same rock sample, as found in this study.…”

“…The presence of an extended or inflected pleon is the subject of deliberation in relation to the taxonomy of the group (Pinto, 1971;Pinto & Adami-Rodrigues, 1996;Pinto & Würdig, 2014).…”

Systematic and palaeoecological significance of the first record of Pygocephalomorpha females bearing oöstegites (Malacostraca, Peracarida) from the lower Permian of southern Brazil

“…; Piñeiro et al . ; Pinto & Würdig ). The recognition of pronounced sexual dimorphism, with females bearing oöstegites and a brood pouch, played a main role in positioning the group within the superorder Peracarida, as a plesion within peracarids, along with the orders Lophogastrida, Mysida and Stygiomysida (Jones et al .…”