Preservação orgânica de musculatura fóssil com detalhe ultracelular

Organic preservation of fossil musculature with ultracellular detail

Maria McNamara 1,*, Patrick J. Orr 1, Stuart L. Kearns 2, Luis Alcalá 3, Pere Anadón 4 and Enrique Peñalver-Mollá 5

- Author Affiliations

1UCD School of Geological Sciences, University College Dublin, Belfield, Dublin 4, Republic of Ireland

2Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK

3Fundación Conjunto Paleontológico de Teruel-Dinópolis, AvenidaSagunto s/n 44002, Teruel, Aragón, Spain

4Consejo Superior de Investigaciones Científicas, Institut de Ciències de la Terra ‘Jaume Almera’, Lluís Solé i Sabarís s/n 08028, Barcelona, Spain

5Museo Geominero, Instituto Geológico y Minero de España, C/ Ríos Rosas 23, 28003 Madrid, Spain

*Author for correspondence (maria.mcnamaral@ucd.ie).

Abstract

The very labile (decay-prone), non-biomineralized, tissues of organisms are rarely fossilized. Occurrences thereof are invaluable supplements to a body fossil record dominated by biomineralized tissues, which alone are extremely unrepresentative of diversity in modern and ancient ecosystems. Fossil examples of extremely labile tissues (e.g. muscle) that exhibit a high degree of morphological fidelity are almost invariably replicated by inorganic compounds such as calcium phosphate. There is no consensus as to whether such tissues can be preserved with similar morphological fidelity as organic remains, except when enclosed inside amber. Here, we report fossilized musculature from an approximately 18 Myr old salamander from lacustrine sediments of Ribesalbes, Spain. The muscle is preserved organically, in three dimensions, and with the highest fidelity of morphological preservation yet documented from the fossil record. Preserved ultrastructural details include myofilaments, endomysium, layering within the sarcolemma, and endomysial circulatory vessels infilled with blood. Slight differences between the fossil tissues and their counterparts in extant amphibians reflect limited degradation during fossilization. Our results provide unequivocal evidence that high-fidelity organic preservation of extremely labile tissues is not only feasible, but likely to be common. This is supported by the discovery of similarly preserved tissues in the Eocene Grube Messel biota.

exceptional faunas taphonomy muscle organic preservation biomolecules

Footnotes

Received July 31, 2009.
Accepted September 22, 2009.
© 2009 The Royal Society

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Diferentemente de outros exemplos de tecidos moles encontrados em âmbar ou em ossos, este foi encontrado dentro do corpo do animal. Os cientistas pensam que este tipo de preservação deve ser muito mais comum no registro fóssil e nos fósseis guardados nos museus.

PERGUNTA INDISCRETA DESTE BLOGGER: Será que o DNA desta salamandra foi preservado por 18 milhões de anos? Só poderemos saber se os cientistas ousarem fazer esta pesquisa.

E aquele caso do T. rex da cientista Mary Higby Schweitzer??? Soft tissue and cellular preservation in vertebrate skeletal elements from the Cretaceous to the present e Analyses of Soft Tissue from Tyrannosaurus rex Suggest the Presence of Protein.