Um novo gênero e espécie de Amblipígeo (Arachnida: Amblypygi: Charinidae) do Membro Crato (Aptiano), Formação Santana, Bacia do Araripe

Abstract

A new genus and a new amblipygeal species are described here based on an almost complete specimen from the limestone of Crato Member (Aptian) of the Santana Formation, the eastern portion of the Araripe Basin in southern Ceará. It is attributed to the Charinidae (Holocene) family, although it presents four pairs of spines arranged in two rows and distally growing in the tibia of pedipalpo, which can be an ancestral feature, sharing with the referred family all other diagnostic features. Tafonomically, the specimen must have undergone a little post-mortem transport, being deposited in the probably anoxic bottom of a lake, thus allowing its preservation. The species of the specimen described should have been troglophile for possessing pulvilli on the legs, so living in rocky crevices in emerged lands near by water bodies, under warm and arid climate. The specimen described is the only known fossil representative of the Charinidae family so far known, being the oldest form of this family, which extends its temporal distribution. It can be assessed the importance and rarity of the Amblypygi specimens occurring in Crato Member, Santana Formation, that outcrops in Nova Olinda. There is little fossil occurrence of this order of arachnid in the Mesozoic, if we consider that, all over the planet and in about 300 million years, only some of these fossil specimens are known.