Early Eocene fossils suggest that the mammalian order Perissodactyla originated in India

• Published in: Nature communications 2014-11, Vol.5 (1), p.5570-5570, Article 5570
• Main Authors: Rose, Kenneth D., Holbrook, Luke T., Rana, Rajendra S., Kumar, Kishor, Jones, Katrina E., Ahrens, Heather E., Missiaen, Pieter, Sahni, Ashok, Smith, Thierry
• Format: Article
• Language: English
• Subjects: 631/181/414; Animals; Biological Evolution; Fossils; Humanities and Social Sciences; India; multidisciplinary; Paleontology; Perissodactyla; Phylogeny; Science; Science (multidisciplinary); Skull
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms6570

Cambaytheres ( Cambaytherium , Nakusia and Kalitherium ) are recently discovered early Eocene placental mammals from the Indo–Pakistan region. They have been assigned to either Perissodactyla (the clade including horses, tapirs and rhinos, which is a member of the superorder Laurasiatheria) or Anthracobunidae, an obscure family that has been variously considered artiodactyls or perissodactyls, but most recently placed at the base of Proboscidea or of Tethytheria (Proboscidea+Sirenia, superorder Afrotheria). Here we report new dental, cranial and postcranial fossils of Cambaytherium , from the Cambay Shale Formation, Gujarat, India (~54.5 Myr). These fossils demonstrate that cambaytheres occupy a pivotal position as the sister taxon of Perissodactyla, thereby providing insight on the phylogenetic and biogeographic origin of Perissodactyla. The presence of the sister group of perissodactyls in western India near or before the time of collision suggests that Perissodactyla may have originated on the Indian Plate during its final drift toward Asia. The phylogenetic and biogeographic origin of Perissodactyla (horses, rhinoceroses and tapirs) is unclear. Here the authors report 54.5 Myr fossils from a sister taxa of Perissodactyla found in India, which suggests that the group may have originated in India before its collision with Asia.