The genus Congestheriella Kobayashi, 1954 (Conchostraca, Afrograptioidea): redescription and new combination to Isaura olsoni Bock from Venezuela and a new species from Argentina (Upper Jurassic)

GALLEGO, O.F.; SHEN, Y.B.; CABALERI, N.; HERNANDEZ, M.

Victoria-Gasteiz

Congreso; IV International Congress of Paleoentomology; 2007

Museo de Ciencias Naturales de Alava

The genus Congestheriella Kobayashi was erected to Estheriella lualabensis Leriche from the Lualaba Series (Upper  Jurassic, Kimmeridgian) from the Congo Republic (Africa). Later, S. Defretin reassigned to Bairdestheria-Estheriella and remarks its importance as a  type fossil of this series, that allows them to assigned to the base of the Kimmeridgian. In 1985, Chen Peiji and Shen Yanbin included this genus in the family Afrograptidae, recently revised  by the second author. Until now, Congestheriella was reported from the Central Africa and with some doubful from the northeast Brazil (Lower Cretaceous, Souza and Missão Velha Formations). In this work, based on new material the genus Congestheriella are emended. The species Isaura olsoni Bock (1953) from the La Quinta Formation (Upper Jurassic, Tithonian) from Venezuela is assigned to this genus. Also, Congestheriella rauhuti sp. nov. one from the Cañadón Asfalto Formation (Middle to Upper Jurassic) from the Argentina is dedscribed. These species are compared with the African form. Other South American species could be related with the new ones, as Graptoestheriella brasiliensis (Oliveira), G. fernandoi Cardoso, Graptoestheriella sp. and Estheriina? costai (Cardoso) from the Upper Jurassic to Lower Cretaceous from different Brazilian basins. According with it stratigraphic distribution and age, Congestheriella is considered as a potential biomarker for the Upper Jurassic-Lower Cretaceous sedimentary succesions from the west Gondwana. Due to it paleogeographic distribution, allow us to propose a biogeographic province including northern South America and Central Africa. Also, different alternative migration routes are proposed for the dispersion across central Africa, northern South America and Patagonia.