Fidelity of terrestrial vertebrate fossils to a modern ecosystem

• Published in: Palaeogeography, palaeoclimatology, palaeoecology palaeoclimatology, palaeoecology, 1999-06, Vol.149 (1), p.389-409
• Main Author: Hadly, Elizabeth A
• Format: Article
• Language: English
• Subjects: community; Holocene; mammals; palaeontology; taphonomy
• ISSN: 0031-0182; 1872-616X
• DOI: 10.1016/S0031-0182(98)00214-4

An exceptionally rich paleontological site, well-dated with 18 radiocarbon samples and containing 10,597 identified mammalian fossils, shows a high affinity to the local habitat with little evidence of long-distance transport of faunal elements. The organic deposits in Lamar Cave, Wyoming, are composed almost entirely of the decomposed collections of wood rats ( Neotoma cinerea) and carnivores, mainly wolves ( Canis lupus) and coyotes ( Canis latrans). The fossil sample, whether analyzed by level or as the total site accumulation, more closely approximates the local living fauna than a modern raptor-pellet and carnivore-scat collection does. The combination of taxa from all but 2 out of 16 levels unambiguously describes the mammalian community of the local sagebrush grassland. Absence of certain extralocal species clearly reflects lack of long-distance (>5 km) transport of non-sagebrush grassland species. If the aim of a paleontological study is specifically to reconstruct the local mammalian community, these data demonstrate that only a minimum of sampling effort may be required for similar localities. However, the data from Lamar Cave do demonstrate that if the goal of a paleontological, or in fact modern, study is to tally the total number of species, an intensive sampling effort is required in order to include the rare taxa. Though time-averaged records indeed may obscure some analyses, particularly those of discerning disharmonious faunas such as those found at the Pleistocene–Holocene transition, this study shows that some time-averaging will benefit the interpretation of faunal diversity of both present and past ecosystems by inclusion of less common taxa.