Imaging coprolite taphonomy and preservation

Authors

Karl Reinhard, University of Nebraska-LincolnFollow
Morgana Camacho, Escola Nacional de Saúde Pública Sergio AroucaFollow
Breyden Geyer, University of Nebraska-Lincoln
Samantha Hayek, University of Nebraska-Lincoln
Chase Horn, University of Nebraska-Lincoln
Kaitlin Otterson, University of Nebraska-Lincoln
Julia Russ, University of Nebraska-Lincoln

ORCID IDs

http://orcid.org/0000-0003-1653-9329 (K. Reinhard)

Document Type

Article

Date of this Version

2019

Citation

Published in Archaeological and Anthropological Sciences (2019) 11:6017–6035 doi:10.1007/s12520-019-00946-w

Comments

Copyright © 2019 Springer-Verlag GmbH Germany, part of Springer Nature. Used by permission.

Abstract

The impact of coprolite taphonomy on parasite remains and aDNA recovery has been recognized. In general, coprolites from sites protected by geologic features such as caves and rock shelters exhibit the best preservation. In contrast, coprolites from open sites can be badly affected by taphonomic processes as shown by analyses of parasite eggs. For eggs, the impact of mites and free living nematodes has been quantified. Mites are associated with poor pinworm egg preservation. In other studies, percolation of water through sediments has a negative impact on egg recovery. We note that dietary remains can also decompose at open sites. Through scanning electron microscopy (SEM), we present examples of screened but chemically untreated microscopic remains. “Panorama” SEM images provide an excellent visual overview of the taphonomy of dietary remains. For this study, our focus is on Southwestern coprolites as a demonstration of diversity within a single region. Examples from caves and rock shelters were examined first to describe the taphonomic challenges for protected sites. Then, attention was turned to coprolites from open sites. In general, the challenges noted for parasite preservation are seen for other microfossils. However, the preservation of lignin, sporopollenin, calcium oxalate, and siliceous microfossils is generally better than cellulose structures. These observations are relevant to the selection process of samples for aDNA analysis and immunological study. This is especially relevant for the gut microbiome since decomposer fungi and bacteria molecular signals could be recovered in metagenomic analysis.