New Understanding of Bizarre Extinct Mammal: Shares Common Ancestor With Rodents, Primates
ScienceDaily (Oct. 11, 2010) — University of Florida researchers presenting new fossil evidence of an exceptionally well-preserved 55-million-year-old North American mammal have found it shares a common ancestor with rodents and primates, including humans.
University of Florida vertebrate paleontologist Jonathan Bloch examines the full skeleton of Labidolemur kayi, a 55-million-year-old extinct mammal with odd ecological adaptations. Reddish-brown epoxy was used during the preparation process to hold the skeleton together. Photo taken Thursday Sept. 30, 2010, at the Florida Museum of Natural History. (Credit: Florida Museum photo by Kristen Grace)
The study, scheduled to appear in the Oct. 11 online edition of the Zoological Journal of the Linnean Society, describes the cranial anatomy of the extinct mammal,Labidolemur kayi. High resolution CT scans of the specimens allowed researchers to study minute details in the skull, including bone structures smaller than one-tenth of a millimeter. Similarities in bone features with other mammals showL. kayi's living relatives are rodents, rabbits, flying lemurs, tree shrews and primates.
Researchers said the new information will aide future studies to better understand the origin of primates.
"The specimens are among the only skulls of apatemyids known that aren't squashed completely flat," said study co-author Jonathan Bloch, an associate curator of vertebrate paleontology at the Florida Museum of Natural History on the UF campus. "They're preserved in three dimensions, which allows us to look at the morphology of the bones in a way that we never could before."
...
Read more here/Leia mais aqui: Science Daily
+++++
Cranial anatomy of Paleocene and Eocene Labidolemur kayi (Mammalia: Apatotheria), and the relationships of the Apatemyidae to other mammals
MARY T. SILCOX1,*, JONATHAN I. BLOCH2, DOUG M. BOYER3, PETER HOUDE4
Zoological Journal of the Linnean Society
Article first published online: 11 OCT 2010
DOI: 10.1111/j.1096-3642.2009.00614.x
Abstract
Keywords: basicranium; Boreoeutheria; Clarkforkian; cranial anatomy;
Euarchontoglires; eutherian phylogeny; Wasatchian; Wyoming
The relationships of the extinct mammalian family Apatemyidae are poorly resolved. Three new, well-preserved crania of Labidolemur kayi from the late Paleocene (Clarkforkian) and early Eocene (Wasatchian) of North America are described in part using ultra high resolution X-ray computed tomography data. These specimens permit the first descriptions of critical components of apatemyid cranial anatomy, such as the composition of the tympanic roof, and the pathways of the internal carotid artery and facial nerve. Results from cladistic analyses of morphological data for known apatemyids and a broad sample of eutherians suggest that apatemyids are basal members of Euarchontoglires, with weak support for a sister-group relationship with Glires. Although apatemyids are sufficiently different from other mammals to be placed in their own order, Apatotheria, it is clear that they are likely to be important for understanding primitive characteristics of Euarchontoglires and Boreoeutheria.
© 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010.
+++++
Professores, pesquisadores e alunos de universidades públicas e privadas com acesso ao site CAPES/Periódicos podem ler gratuitamente este artigo do Zoological Journal of the Linnean Society e de mais 22.440 publicações científicas.
