The Ostracods genus Hemingwayella: A journey from Mesozoic to Recent, North to South and Warn to Cold

CUSMINSKY , G. C.; CARIGNANO, A; FERRERO, L; CEOLIN, D; WHATLEY R. C.

Mendoza

Congreso; 4th International Paleontological Congress; 2014

International Paleontological Asociation

The cytheroid ostracod Hemingwayella Neale, a marine genus with a gondwanine distribution, was first described from the Upper Cretaceous (Santonian) of Western Australia, in sediments representative of a relatively warm and shallow shelf sea environments. In Argentina, Bertels described two species, P. intensosulcata [ex Orthonotacythere?] and Paracytheridea rionegrina, which can now both be seen clearly to belong to a single species of Hemingwayella. This species was encountered in the Allen and Jaguel formations (Upper Campanian to Lower Danian) of the Neuquén Basin, which occurs in both the provinces of Neuquén and Río Negro and in similar inferred, essentially warm palaeoenvironments as the Western Australian species. Conversely, species such as Hemingwayella pumilio (Brady) and H. antarctica (Hartmann) were described from the Pliocene to Recent in Antarctic deep waters, shelf and littoral sediments of Argentina, Malvinas (Falklands) Islands and Brazil, and the southernmost parts of the Indian Ocean. There is also,a possible record from the shelf of southwestern Africa. Despite the Argentinian Maastrichtian record, there are no subsequent Palaeogene occurrences. It is suggested, therefore, that this taxon after the K/P boundary, retreated to refugia which have not been sampled or have been destroyed by normal geological processes. Some of these refugia, however, supplied those populations which, as Lazarus taxa in South America and the Southern Ocean, have survived to the present day.