A new species of Andhracoides Wilson and Ranga Reddy, 2011 (Isopoda: Hypsimetopidae) from Belum Cave, Andhra Pradesh, India, with a phylogenetic review of the family

Abstract

Andhracoides gebaueri n. sp. from Belum Cave is the second hypogean representative of the genus Andhracoides Wilson and Ranga Reddy, 2011, the first one being Andhracoides shabuddin Wilson and Ranga Reddy, 2011, from Guthikonda Cave; both these caves are located in southeastern India. The new species can be easily distinguished from A. shabuddin by the following features: body with elongate robust setae on low bumps adjacent to prominent pereional mid-dorsal setal rows; pereionites wider than long in lateral view; maxillipeds with only one coupling hook each; and distal tip of appendix masculina extending beyond midpoint of the exopod. Discovery of this new species adds to the known diversity and distribution of the Indian hypsimetopid fauna. A key to the taxa of the Indian Hypsimetopidae is given. A phylogenetic analysis of 68 species of Phreatoicidea and out-groups have yielded eight trees with strongly supported clades of Hypsimetopidae, Andhracoides + Nichollsia and Andhracoides. The trees are consistent with Gondwana tectonic separation of Indian-Australian continents and imply that the family as a whole might have an age of origin earlier than the initial separation of India and Australia. Because Hypsimetopidae do not show the derived features of the remainder of the phreatoicideans that appear in the fossil record, their origin could predate the oldest known phreatoicidean fossils in the late Paleozoic.