Alguns himenóptera Apocrita do Membro Crato (Aptiano) da Formação Santana, Bacia do Araripe

Abstract

This thesis describes new specimens of Hymenoptera from the laminated limestone of Crato Member (Aptian), Santana Formation, Araripe Basin that outcrops at Nova Olinda district, south of the Ceará State, Brazil. It also summarizes the occurrences of fossil Hymenoptera, mainly the Early Cretaceous fauna. The study of ten specimens of Hymenoptera Apocrita described here revealed the occurrence of three families: Sphecidae (Cretosphex magnus Darling 1990 and C. parvus Darling 1990), Sapygidae (Cretofedtschenkia santanensis Osten 2007), and Evaniidae, this latter represented by a new genus and a new species. In the Araripe Basin, suborder Symphyta is unusual, and Apocrita are more diverse, with Parasitica forms (Ichneumonoidea, †Ephialtitidae, Proctotrupidae, and †Mesoserphidae), and Aculeata species of Sphecidae (the most abundant), Rhopalosomatidae, Sapygidae, Scoliidae, Tiphiidae, Vespidae, and possibly Formicidae. Throughout its geological history, Hymenoptera are mainly represented by wasps. They are relatively common at Jurassic time, showing a long period of great diversification (from Late Jurassic to Tertiary), when rose more than 80% of all 107 families with fossil records. The extinction that affected the organisms at the Cretaceous end seems to have also affected Hymenoptera, which show the largest number of families extinct in its history. Hymenoptera from the Crato Member are preserved by mineral substitution, articulated, with open wings, and extended legs, showing major number of female, without known larvae. It is a distinct fauna from the main known Early Cretaceous himenopterofaunas (Spain, Australia, Mongolia and Siberia), not sharing any genre, but having in common the small participation of Symphyta. The history of Cretaceous Hymenoptera research in Brazil shows that the greatest number and the most significant papers have been accomplished by foreign researchers, so the most of Hymenoptera specimens from the Crato Member of the Araripe Basin is out of Brazil. It is therefore necessary that the Brazilian researchers take the study of this order of insects that occur in the Santana Formation, performing studies which will effectively contribute to the better understanding of the himenopterofauna of the Araripe Basin and enriching the Brazilian collections with their fossils.