Preserved collagen reveals species identity in archaeological marine turtle bones from Caribbean and Florida sites

Virginia L Harvey; Michelle J LeFebvre; Susan D deFrance; Casper Toftgaard; Konstantina Drosou; Andrew C Kitchener; Michael Buckley

doi:10.1098/rsos.191137

Preserved collagen reveals species identity in archaeological marine turtle bones from Caribbean and Florida sites

R Soc Open Sci. 2019 Oct 30;6(10):191137. doi: 10.1098/rsos.191137. eCollection 2019 Oct.

Authors

Virginia L Harvey¹, Michelle J LeFebvre², Susan D deFrance³, Casper Toftgaard^{4

5}, Konstantina Drosou⁶, Andrew C Kitchener^{7

8}, Michael Buckley¹

Affiliations

¹ Manchester Institute of Biotechnology, School of Earth and Environmental Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.
² Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA.
³ Department of Anthropology, University of Florida, Gainesville, FL 32611, USA.
⁴ The SAXO Institute, University of Copenhagen, Karen Blixens Plads 8, 2300 København S, Denmark.
⁵ National Museum of Denmark, Nationalmuseet, Ny Vestergade 10, Prinsens Palæ, DK-1471, København K, Denmark.
⁶ KNH Centre for Biomedical Egyptology, School of Biological Sciences, 99 Oxford Road, Manchester, M13 9PG, UK.
⁷ Department of Natural Sciences, National Museums Scotland, Chambers Street, Edinburgh EH1 1JF, UK.
⁸ The University of Edinburgh, Institute of Geography, School of Geosciences, Drummond Street, Edinburgh, EH8 9XP, UK.

Abstract

Advancements in molecular science are continually improving our knowledge of marine turtle biology and evolution. However, there are still considerable gaps in our understanding, such as past marine turtle distributions, which can benefit from advanced zooarchaeological analyses. Here, we apply collagen fingerprinting to 130 archaeological marine turtle bone samples up to approximately 2500 years old from the Caribbean and Florida's Gulf Coast for faunal identification, finding the vast majority of samples (88%) to contain preserved collagen despite deposition in the tropics. All samples can be identified to species-level with the exception of the Kemp's ridley (Lepidochelys kempii) and olive ridley (L. olivacea) turtles, which can be separated to genus level, having diverged from one another only approximately 5 Ma. Additionally, we identify a single homologous peptide that allows the separation of archaeological green turtle samples, Chelonia spp., into two distinct groups, which potentially signifies a difference in genetic stock. The majority of the archaeological samples are identified as green turtle (Chelonia spp.; 63%), with hawksbill (Eretmochelys imbricata; 17%) and ridley turtles (Lepidochelys spp.; 3%) making up smaller proportions of the assemblage. There were no molecular identifications of the loggerhead turtle (Caretta caretta) in the assemblage despite 9% of the samples being morphologically identified as such, highlighting the difficulties in relying on morphological identifications alone in archaeological remains. Finally, we present the first marine turtle molecular phylogeny using collagen (I) amino acid sequences and find our analyses match recent phylogenies based on nuclear and mitochondrial DNA. Our results highlight the advantage of using collagen fingerprinting to supplement morphological analyses of turtle bones and support the usefulness of this technique for assessing their past distributions across the Caribbean and Florida's Gulf Coast, especially in these tropical environments where DNA preservation may be poor.

Keywords: ZooMS; aDNA; collagen fingerprinting; marine turtles; species identification; zooarchaeology.

Associated data

figshare/10.6084/m9.figshare.c.4700114
Dryad/10.5061/dryad.6fb6676