Taphonomy of vertebrate assemblages from the Paleogene of northwestern Wyoming and the Neogene of northern Pakistan

• Published in: Palaeogeography, palaeoclimatology, palaeoecology palaeoclimatology, palaeoecology, 1995-05, Vol.115 (1), p.157-180
• Main Authors: Badgley, Catherine, Bartels, William S., Morgan, Michele E., Behrensmeyer, Anna K., Raza, S.Mahmood
• Format: Article
• Language: English
• ISSN: 0031-0182; 1872-616X
• DOI: 10.1016/0031-0182(94)00110-T

We compare the taphonomy of vertebrate assemblages from two long continental records—the early Paleogene of the Bighorn Basin, Wyoming, and the Neogene Siwalik sequence of northern Pakistan. Both sequences contain a similar array of fluvial facies, and the abundance of these facies differs among formations. We document environments of preservation of vertebrate localities over time to determine comparability of fossil assemblages within and between sequences. Changes in sample size and species richness are noted to reveal potential sampling effects on patterns of faunal turnover. Preservational history determined the environment, sample size, quality of specimens, taxonomic composition, and spatial and temporal resolution of fossil assemblages and thereby the quality of the fossil record and its suitability for further analyses. In both sequences, changes in prevailing taphonomic processes reflect changes in lithofacies and habitat distribution. Correlated changes are found in fossil productivity, species richness, and faunal composition. Both sequences contain some episodes of apparent faunal change in which appearances and disappearances of rare taxa can be attributed principally to changes in sample size. The Paleogene record has high taxonomic resolution (i.e., to genus or species) for most mammalian fossil remains. Temporal and spatial averaging of Paleogene fossil assemblages changes with lithofacies. The Neogene record has higher taxonomic resolution for remains of small mammals (