Horses, Hemiones, Hydruntines? Assessing the Reliability of Dental Criteria for Assigning Species to Southwest Asian Equid Remains

Abstract

Many faunal assemblages across southwest Asia contain the remains of multiple wild equid species, which may reflect individual prehistoric human populations' use of different hunting and/or landscape exploitation strategies. Accurate equid species assignments are therefore important. This paper tests the extent to which zooarchaeologists agree on equid species assignments made using commonly used zooarchaeological dental identification criteria. Seven zooarchaeologists individually use published criteria to assign species to equid teeth from Neolithic Çatalhöyük in central Anatolia, then use Fleiss' kappa to measure our reliability of agreement. We assess our degrees of agreement for species assignments made using scanned images versus actual specimens and for mandibular teeth versus maxillary teeth. Having failed to achieve significant agreement, we conclude that zooarchaeologists should be cautious about species assignments made using these methods.

Environment, seasonality and hunting strategies as influences on Natufian food procurement: The faunal remains from Shubayqa 1

“…The sample is small and difficult to compare, but it seems probable that many of the equids are onager, especially given the similarity of E. hydruntinus to hemiones in the fossil record (Burke et al 2003); as well as genetic evidence (Orlando et al 2006;2009) implying that they should be considered as one species. Whilst the use of teeth for species identification has been questioned recently (Twiss et al 2017), the use of geometric morphometrics may offer a fruitful avenue of future investigation (Cucchi et al 2017), but the equid bones from Shubayqa 1 are tentatively assigned as Equus hemionus and images presented in Fig. 3 will allow comparison in the future.…”

Assessing reproducibility in faunal analysis using blind tests: A case study from northwestern North America

“…As demonstrated in previous studies, the a priori assumption that any two zooarchaeologists will produce comparable results is not defensible (Fisher, 2015;Gobalet, 2001), even when they follow Vertebrae the same detailed identification protocols (Twiss et al, 2016). Similarly, we argue the methods and protocols used by an individual or research team to generate data over the course of a multi-year project have the potential to 'drift,' producing results from different stages of the project that are not comparable.…”

“…Our study contributes to the growing interest in quality assurance in zooarchaeology (e.g. Fisher, 2015;Morin et al, in press;Twiss et al, 2016) by introducing simple quantitative methods for assessing reliability in faunal analysis through reanalysis that we developed during study of fish remains from Tsewhit-zen, a large Native American village from coastal Washington State, U.S.A. (Figure 1) that was excavated extensively in 2004. The fishbone study is part of a larger analysis of mammal, bird, fish and shellfish remains that aims to understand how animal resources and in turn people were affected by great earthquakes and other environmental forces, such as climate change and local bay development, over the past ~2,200 years.…”

Zonkey: A simple, accurate and sensitive pipeline to genetically identify equine F1-hybrids in archaeological assemblages

“…The following non-mutually exclusive factors make equine hybrid identification particularly difficult: (i) the great morphological similarity between bones of the parental species (Peters, 1998); (ii) their co-occurrence in particular regions, like Southwest Asia (Twiss et al, 2016), where four equine species (the donkey, the hemione, the horse and the recently extinct hydruntine, Equus hydruntinus) co-existed until very recently (Eisenmann and Mashkour, 1999;Mashkour, 2002Mashkour, , 2003Vila, 2006;Orlando et al, 2006); (iii) the great morphological variation within domestic horses; and (iv) our limited knowledge of the hybrid morphological space, due to the scarcity of modern reference material (Baxter, 1998;Chuang, 2016;Johnstone, 2004). While some 'diagnostic' morphological traits have been postulated in different equine species, including mules (Davis, 1980;Eisenmann, 1986;Peters, 1998;Uerpmann and Uerpmann, 1994), these are not unanimously considered as valid (Baxter, 1998;Chuang, 2016;Groves and Willoughby, 1981;Twiss et al, 2016). Finally, the equid remains commonly recovered from archaeological sites are fragmentary, thus reducing the number of diagnostic traits available for taxonomic identification (Baxter, 1998;Zeder, 1986).…”