New specimens and comments on the Crato formation araneofauna, Lower Cretaceous of Brazil

ELIS MARIA GOMES SANTANA; GUSTAVO GOMES PINHO; IVAN L. F. MAGALHAES; ANTÔNIO ÁLAMO FEITOSA SARAIVA

Congreso; 22nd International Congress of Arachnology; 2023

Due to their fragility and lack of mineralization, spiders are rarely preserved in the fossil record, being mostly found in amber and, more rarely, in sedimentary rocks. Until now, Cretaceous fossil spiders deposited in lacustrine environments have been found at eight different locations, with 31 specimens known in the literature. The Crato Formation of Brazil is one of the most important locations in the study of Cretaceous spiders, as it is one of the few deposits in the southern hemisphere to preserve such animals. However, few species of fossil spiders have been described from the Crato Formation so far. Here, we carried out the study of twelve fossil spiders deposited in the collection of the Paleontology Laboratory of the Regional University of Cariri. Six of the specimens were identified as Cretaraneus martinsnetoi, an abundant Araneomorphae species in the Crato Formation. Other representatives of this infraorder were identified in a limestone plate containing five spiders preserved next to each other; however, it was not possible to attribute them to lower taxonomic levels due the lack of diagnostic characters. Apart from these, only one specimen was identified as belonging to Mygalomorphae, also with an uncertain taxonomic position, due to the poor preservation. Given the rarity of spiders in lacustrine Cretaceous deposits, the new specimens found in the Crato Formation and our research aimed towards the analysis and morphological description of this group will expand our knowledge of the araneofauna from the Cretaceous of Gondwana.