Habitat preference of extant African bovids based on astragalus morphology: operationalizing ecomorphology for palaeoenvironmental reconstruction

Bovid ecomorphology and hominin paleoenvironments of the Shungura Formation, lower Omo River Valley, Ethiopia

“…The environmental categories used here were open (grassland, arid country, ecotones bordering open country), light cover (light bush, tall grass), heavy cover (heavy bush, woodland), and forest (Kappelman et al, 1997;Plummer et al, 2008). The assignment of bovid taxa to habitat preferences generally followed that of Plummer et al (2008), except for Madoqua kirkii, which was here assigned to the light cover category following field observations of habitat preferences in its range (Bishop, Plummer, pers. obs).…”

“…2; Table 2). Logarithms of these measurements and several indices derived to reflect shape differences were subjected to a quadratic discriminant function analysis (Plummer et al, 2008, Bishop et al, 2011SYSTAT v. 13). Discriminant function analysis (DFA) was used to test the relationship between astragalus morphology and habitat preference among modern bovids.…”

“…The variables used are those that best discriminate between the groups to which specimens ultimately will be assigned. As in our previous work (e.g., Plummer and Bishop, 1994;Plummer et al, 2008;Bishop et al, 2011) we used quadratic, rather than linear, discriminant function analysis. In linear DFA, identical within-group covariance matrices are pooled to calculate a linear discriminant function .…”

“…2, Table 2). This variable list was somewhat different from that used by Plummer et al (2008) on modern astragali, because certain landmarks or regions of the astragalus were not always preserved in the fossils. We selected variables that were frequently present in fossil specimens so as to maximize the sample size of fossils available for analysis, while preserving the highest possible classification success rate.…”

“…Previous work has demonstrated that bovid astragali can be classified successfully into habitat preference categories by analysis of morphologies associated with particular habitat preferences (DeGusta and Vrba, 2003;Plummer et al, 2008;Barr, 2014). This method can be used to analyze fossil bovid astragali with known stratigraphic provenance.…”