First record of Palaeomohria Archangelsky (Anemiaceae) for the Cenomanian of Santa Cruz Province

ARI IGLESIAS; VIVIANA BARREDA; PATRICIO SANTAMARINA; AUGUSTO VARELA

La Plata

Congreso; Reunión de Comunicaciones de la Asociación Paleontológica Argentina; 2019

In present days, the fern family Anemiaceae is composed by two genera: Mohria Swartz and Anemia Swartz. Mohria grows in south-east Africa and Madagascar, while Anemia lives in the Neotropics, Africa and India. The fossil record of Mohria is scarce, represented by leaf impressions (Mohriopsis Appert) from the Late Jurassic of Madagascar ?whose affinities with the extant genus are controversial?; and dispersed spores (Palaeomohria Archangelsky) from the Albian of Patagonia. Palaeomohria is related to Mohria by having large equatorial diameter and cicatricose sculpture with hollow muri. Here we present a new record of Palaeomohria for the Cenomanian Mata Amarilla Formation, in the surroundings of Tres Lagos Town (Warring Hill section, 49°31?16.8??S 71°29?7.7??W), Santa Cruz Province. In the studied area, the Mata Amarilla Formation transitionally overlies the Albian Piedra Clavada Formation, the unit that bears the oldest record of the genus. This is the first record of this taxon for the Late Cretaceous, extending its stratigraphic range and the importance of this fern group in Patagonia. The presence of Palaeomohria in Albian to Cenomanian sediments of the Austral Basin shows that the Mohria-like group had survived in Patagonia at least up to the earliest Late Cretaceous.