ABSTRACT: Foreman established the genus Polyentactinia from three species. Since then, 26 additional Polyentactinia species have been described. Together, their biostratigraphic range is Late Cambrian to Early Permian. Such a long range for one genus is unlikely. Further, the species were assigned to Polyentactinia because of their shell wall’s angular meshwork, disregarding other characteristics. From re-examination of the type species, P. craticulata, we find that, unlike the genus and type species diagnoses, it has a thin one-layered shell wall of fine spongy meshwork with a latticed base, an internal spicule with seven rays extending to main spines, and one short ray directed toward the single large pylome. Such specimens may belong to the Pylentonemidae. Recently three genera, including two Cretaceous genera, have been assigned to the Polyentactiniidae, but they share no characteristics with Polyentactinia that would tie them to the Polyentactiniidae, regardless of how diverse and unrelatedly heterogeneous the species in Polyentactinia. Therefore, the family Polyentactiniidae may no longer be a valid taxon. Except for the type species, among 29 Polyentactinia species, other researchers have reorganized five species; we reassign 24 species in this paper. Among them, six species share characteristics with a previously unreported species from the Ohio Shale fauna. For those, we establish the genus Costaentactinia and, for the unreported species, C. foremanae. We also establish Retentactinia spongiosa n. sp. that is closely related to one of the three species on which Foreman based her genus.
You are not registered as a current subscriber. If your institution has an active subscription, contact us to ask for help with your computer's IP address. If you have an active personal subscription, log in.
Subscribe to Micropaleontology
|Online only||Added print|