Variable Ovicaprid Diet and Faecal Spherulite Production at Amara West, Sudan

ABSTRACT

This paper presents the results of integrated geoarchaeological and archaeobotanical analyses of desiccated and charred ovicaprid dung pellets from the New Kingdom pharaonic settlement of Amara West (Sudan). These analyses reveal diagnostic phytolithic evidence for considerable variations in plant diet amongst the site’s ovicaprid population. These data shed light on aspects of ancient animal husbandry practice, the settlement’s subsistence economy and residents’ exploitation of natural resources. We also observe that specific phytolith types correlate with the presence (and quantity) or absence of calcium carbonate faecal spherulites in analysed dung pellets. This evidence, augmented by experimental analysis of analogous modern plant material, suggests that dietary Ca intake is implicated in faecal spherulite crystallization within the ovicaprid digestive system.

KEYWORDS:

• Dung spherulites
• phytoliths
• micromorphology
• animal husbandry
• urban archaeology
• New Kingdom Egypt

Acknowledgements

All geoarchaeological and archaeobotanical samples were taken within the framework of the British Museum’s Amara West Research Project, of which both authors are members. We thank the project’s director Neal Spencer for permission to sample the site, and acknowledge the National Corporation of Antiquities and Museums (Sudan) for granting the archaeological concession and permitting the export of samples for analysis; Director General Abdelrahman Ali Mohamed deserves particular thanks. We thank the Cambridge University Botanical Gardens for providing contemporary plant specimens, especially Julie Clos, Mar Milan and Alexander Summers who arranged and supervised sampling. We also thank Caroline Cartwright for commenting on a draft of this work. We are grateful to two anonymous reviewers, whose constructive comments improved the paper. ICP-OES analysis of plant specimens was undertaken in the Geography Science Laboratories of the Department of Geography Department, University of Cambridge. We thank senior technical officer Steve Boreham for advice on experiment design and senior technician Laura Healy for undertaking the analysis. Thanks to the McBurney laboratory director Charles French for helpful comments, and chief research technician Tonko Rajkovaca for assistance with thin section manufacture.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Matthew Dalton, Department of Archaeology, University of Cambridge, Cambridge, UK. [email protected]; [email protected].

Philippa Ryan, Department of Scientific Research, The British Museum, London, UK.

ORCID

Matthew Dalton http://orcid.org/0000-0002-1651-7384

Philippa Ryan http://orcid.org/0000-0001-6645-9744

Notes

1 The hyperarid climatic conditions prevailing in contemporary northern Sudan have likely changed little since ∼5000–4500 cal BP (Welc and Marks 2014, with references).

2 Geoarchaeological evidence for domestic animal penning at Amara West will be considered in a forthcoming paper by M. Dalton and colleagues.

3 The multicell analysis excluded pellets containing no multicells (4817 and 12023).

4 The small, mixed goat/sheep herds kept by many families on present-day Ernetta Island are permanently penned in brush enclosures so as not to damage nearby fields.

5 It is not possible to differentiate grass culm/leaf phytoliths in many cases.

6 Generally, only single or relatively few ovicaprid dung pellets from given modern contexts have been analysed for faecal spherulite and basic phytolith content (i.e. Shahack-Gross and Finkelstein 2008; Portillo, Valenzuela, and Albert 2012, 2014; Elliott et al. 2015).

7 Ernetta Island, for example, would probably provide a poor case study, as animals are foddered on predominantly Ca-rich legumes and other herbaceous dicots year-round.

8 The Ca requirements of mature male ruminants are seldom calculated, but will be somewhat lower than these examples.

Additional information

Funding

The research presented here was undertaken in part during M. Dalton’s Arts and Humanities Research Council-funded PhD [grant number 1233285]. P. Ryan was also supported by the Arts and Humanities Research Council [grant number AH/K006193/1] as principle investigator for the project ‘Sustainability and subsistence systems in a changing Sudan’. The Amara West Research Project, including the excavations which produced the samples discussed here, has been supported by funding from The Leverhulme Trust (2010–2014) and the Qatar-Sudan Archaeological Project (2013–2018). Micromorphological thin section production was funded by the Charles McBurney Laboratory for Geoarchaeology, University of Cambridge.