A new invertebrate from the ponta grossa formation (Devonian), Paraná Basin, Brazil

Abstract

Pontagrossia reticulata n. gen. et sp. is described from the Lower Devonian (Emsian) Ponta Grossa Formation, Paraná Basin. The species is based on morphological characteristics shared by three contiguous casts clearly representing a single species, if not the same individual. The shape and organization of the fossil resembles that in some sponges, but until diagnostic evidence of its affinities can be recognized in these specimens, the new taxon will be left in open nomenclature. Nevertheless, this fossil is unlike any other invertebrate, plant, or algal fossil already known from the Ponta Grossa Formation, and thus represents a novel addition to the diversified cold-water Devonian paleobiota of Brazil. place in a moderately bioturbated succession of clayey-silty shale at least four meters thick near the top of the Jaguariaíva Member of the Ponta Grossa Formation on the NW side of state highway PR-092 between Jaguariaíva and Arapoti, Paraná (Figure 1B). This same interval yielded diverse fossils, some in place and others overturned or dislocated, mostly as molds and casts of bivalves, Tentaculitoidea, conularids, trilobites and at least four taxa of unbroken, solitary, and grouped brachiopods.