High-fidelity organic preservation of bone marrow in ca. 10 Ma amphibians
- Maria E. McNamara1,
- Patrick J. Orr1,
- Stuart L. Kearns2,
- Luis Alcalá3,
- Pere Anadón4 and
- Enrique Peñalver-Mollá5
- 1School of Geological Sciences, University College Dublin, Belfield, Dublin 4, Ireland
- 2Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK
- 3Fundación Conjunto Paleontológico de Teruel-Dinópolis, Avenida Sagunto s/n, 44002 Teruel, Aragón, Spain
- 4Consejo Superior de Investigaciones Científicas, Institut de Ciencies de la Terra “Jaume Almera”, Lluís Solé i Sabarís s/n, 08028 Barcelona, Spain
- 5Division of Invertebrate Zoology, American Museum of Natural History, Central Park West at 79th Street, New York, New York 10024-5192, USA
Abstract
Bone marrow in ca. 10 Ma frogs and salamanders from the Miocene of Libros, Spain, represents the first fossilized example of this extremely decay-prone tissue. The bone marrow, preserved in three dimensions as an organic residue, retains the original texture and red and yellow color of hematopoietic and fatty marrow, respectively; moldic osteoclasts and vascular structures are also present. We attribute exceptional preservation of the fossilized bone marrow to cryptic preservation: the bones of the amphibians formed protective microenvironments, and inhibited microbial infiltration. Specimens in which bone marrow is preserved vary in their completeness and articulation and in the extent to which the body outline is preserved as a thin film of organically preserved bacteria. Cryptic preservation of these labile tissues is thus to a large extent independent of, and cannot be predicted by, the taphonomic history of the remainder of the specimen.
Footnotes
-
- Accepted 14 March 2006.
- Received 14 December 2005.
- Revision received 10 March 2006.
- Geological Society of America
