The impact of decay and disarticulation on the preservation of fossil birds

Taphonomic experiments on bird carcasses were carried out at two field sites in southern Florida, a brackish swamp and a marine embayment. Observations were made on. carcasses protected by metal cages, and unprotected carcasses. Scavengers were the primary agent of degradation in the case of unprotected carcasses. The sequence of morphological de cay was similar in brackish and marine conditions, and there was no significant difference in the rate of weight Loss. This provides a basis for the interpretation of fossil examples from selected Lagerstatten: Solnhofen (Jurassic), and Messel, Green River and Seymour Island (Eocene). These fossil avifaunas show varying degrees of transport-induced disarticulation, reflecting the original habitat of the birds and the conditions of deposition. A decay equation derived from experimentally produced weight-loss data allows the time elapsed between death and stabilization of the carcass to be estimated for fossil birds. This provides constraints on taphonomic interpretations of the Lagerstatten in which they occur.