Systematics of the Australian Mygalomorph Spider Genus Ixamatus Simon (Diplurinae: Dipluridae: Chelicerata

Abstract

Ixamatus is revised, and now includes eight species, six of which are new: I, barina, sp. nov., I. caldera, sp. nov., I. candidus, sp, nov., I. fischeri, sp, nov., I. musgravei, sp. nov., and I. webbae, sp. nov.; the remaining two species, I. varius and I. broomi, are diagnosed. Ixamatus is found in montane rainforest and heath from northern Queensland to northern New South Wales. The ascopulate or thinly scopulate tarsi, the absence of a second row of teeth on the posterior tarsal claws of some species, the presence of an elevated tarsal organ, the highly pustulose cuticle, and the occurrence of a maxillary serrula together make Ixamatus an evolutionary enigma. The relationships of the genus are confused by conflicting apomorphies and plesiomorphies.