New species of Myrmicium Westwood (Psedosiricidae = Myrmiciidae: Hymenoptera, Insecta) from the Early Cretaceous (Aptian) of the Araripe Basin, Brazil.

Luís C.B Freitas,Alexandr P Rasnitsyn,Geraldo J.B Moura,Marcio Mendes

doi:10.1590/0001-3765202020200479

Abstract

This paper records the first occurrence of the genus Myrmicium Westwood, 1854 in the Cretaceous of Gondwana and describes it as a new species Myrmicium araripterum sp. nov, based on the most complete specimen of this genus yet known, which represents the largest specimen of the grade "Symphyta" ever found in the Crato Formation.

Highlights

Having the most complete continental record of the end of the rift phase of the Brazilian continental margin (Castro et al 2006), the Araripe Sedimentary Basin has one of the most important Mesozoic Konservat Lagerstätten of Gondwana (Maisey 1991, Martill 1993, Kellner 2002)
The fossil object of study in this work comes from the Crato Formation of the Santana Group (Post-Rift I phase) which is subdivided into the Crato, Ipubi, and Romualdo Formations (Neumann & Cabrera 1999) (Figs. 1 and 2)
In its general appearance as well as wing venation Myrmicium is close to Siricidae: it shares with various siricids, with living ones, large body size; wings with deeply corrugated

Summary

Introduction

Having the most complete continental record of the end of the rift phase of the Brazilian continental margin (Castro et al 2006), the Araripe Sedimentary Basin has one of the most important Mesozoic Konservat Lagerstätten of Gondwana (Maisey 1991, Martill 1993, Kellner 2002). With regard to the insects in the Araripe Basin, the vast majority are restricted to the Crato Formation. One insect record is reported for the Romualdo Formation (Freitas et al 2016). The entomofauna is badly underexplored, and there are still many families under analyses, represented by taxa yet unnamed within the Crato Formation (Bechly 2007, Barling et al 2013). Hymenoptera are one of the largest and most diverse insect orders. Their most common classification encompass suborder Apocrita (=Vespina) and the grade “Symphyta” (=Siricina), even though the latter is characterized only by plesiomorphies (primarily by the absence of constriction in the first and second abdominal segments), and so represents a grade rather than a monophylum

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