The first whipspider (Arachnida: Amblypygi) and three new whipscorpions (Arachnida: Thelyphonida) from the Lower Cretaceous Crato Formation of Brazil

Abstract

The first whipspider (Arachnida: Amblypygi) and three new examples of whipscorpions (Arachnida: Uropygi: Thelyphonida) are described from Lower Cretaceous (Aptian) strata of the Crato Formation, Ceará State, Brazil. The whipspider is described as Britopygus weygoldti gen. et sp. nov. It resembles members of the extant family Charinidae, but cannot be unequivocally placed. Two of the whipscorpions are referred to Mesoproctus rowlandi Dunlop, 1998 and one could be a subadult, since, like juveniles of extant species, it has a relatively broad anterior sternum. There are differences between these two specimens in pedipalp and flagellum morphology, but both characters are variable within extant species. The third and largest whipscorpion is incomplete and referred to Mesoproctus sp. Its carapace length is equal to or exceeds that of the largest known extant genus Mastigoproctus Pocock, 1894.