Unmasking a gap: A new oligoneuriid fossil (Ephemeroptera: Insecta) from the Crato Formation (upper Aptian), Araripe Basin, NE Brazil, with comments on Colocrus McCafferty

Abstract

The Crato Formation (Araripe Basin) preserves one of the most diverse entomofaunas of the Cretaceous. Among the groups of insects, mayflies stand out in abundance, but among them oligoneuriids are especially rare. A newly discovered adult oligoneuriid from this unit is here described as Incogemina nubila gen. et sp. nov. and new subfamily Incogemininae. A phylogenetic analysis recovered the new taxon as the sister group to the species-rich and cosmopolitan Oligoneuriinae. The paratype of Colocrus indivicum , described as an "oligoneuriid" from the same unit, is here reviewed and considered as belonging to the family Hexagenitidae. The biogeographical and taxonomic implications of this discovery and the phylogenetic position of Incogemina nubila are discussed. Incogemina bridge an important morphological gap between the Oligoneuriinae and the extant Chromarcys . Also, it demonstrates that the divergence between Oligoneuriinae and Incogemininae probably occurred in South America.

Gondwana breakup under the ephemeral look

“…(1) Root was calibrated to represent the minimum and maximum (242–290 mya) ages of fossil species Protereisma permianum Sellards 1907 (Protereismatidae), believed to be one of the stem groups of Ephemeroptera (Godunko et al, 2011; Grimaldi & Engel, 2005; Sroka et al, 2015), and the mayfly Triassonurus doliiformis Sinitshenkova & Papier, 2005 (Siphlonuridae), the lineage with the oldest origin in our dataset (Lognormal distribution, offset = 242.0, Mean = 8.5, Standard deviation = 1.0, mean in real space). (2) Oligoneuriidae initial diversification was calibrated based on Incogemina nubile Storari et al, 2020. (Oligoneuriidae) (Lognormal, offset = 112.6, M = 30.0, S = 1.0, mean in real space).…”

Digging deeper into colonial palaeontological practices in modern day Mexico and Brazil

“…The Palaeontology Museum 'Plácido Cidade Nuvens' at Santana do Cariri, which contains thousands of fossils from the Araripe Basin, was founded in 1985-presumably before most of the Araripe Basin fossils included in this study were collected. Currently, local researchers associated with this museum coordinate controlled excavations in the region [156][157][158], and several scientific publications have been produced based on these materials [159][160][161][162][163][164][165] (see more publications in electronic supplementary material, table S2). This museum would be the logical place to store a number of holotypes and other important fossils that are now in foreign collections.…”

The Ephemeroptera (Hexapoda, Insecta) from the Lower Cretaceous Crato Formation (NE Brazil): a new genus and species, and reassessment of Costalimella zucchii Zamboni, 2001 and Cratogenites corradiniae Martins-Neto, 1996

“…Fossil mayflies are especially diverse in the Early Cretaceous, partly due to their abundance and exquisite preservation in the Aptian strata of the Crato Formation (Araripe Basin), northeast Brazil. Fifteen mayfly species have been described from this lithostratigraphic unit, including representatives of the families Australiphemeridae (Australiphemera revelata McCafferty, 1990 and Microphemera neotropica McCafferty, 1990), Baetiscidae (Protobaetisca bechlyi Staniczek, 2007), Ephemeridae (Cratonympha microcelata Martins-Neto and Caldas, 1990), Euthyplociidae (Pristiplocia rupestris McCafferty, 1990), Hexagenitidae (Protoligoneuria limai Demoulin, 1955, Cratohexagenites longicercus Staniczek, 2007and Cratohexagenites minor Staniczek, 2007, Oligoneuriidae (the recently described Incogemina nubila Storari et al, 2020, Colocrus magnum Staniczek, 2007and Colocrus indivicum McCafferty, 1990, recently reclassified as an hexagenitid by Storari et al, 2020), Polymitarcyidae (Caririnympha mandibulata Martins-Neto and Caldas, 1990), Potamanthidae (Olindinella gracilis Martins-Neto and Caldas, 1990), and possibly Siphlonuridae (Costalimella nordestina Martins-Neto, 1996 andCostalimella zucchii Zamboni, 2001). In fact, several previously proposed species not listed above have been synonymized in the last years (see review of Staniczek, 2007).…”