Salvadora Baird and Girard 1853

Genus SALVADORA Baird and Girard, 1853 Diagnosis. Generally, Salvadora can be identified by the combination of the following characters: (1) a thin, relatively low neural spine that gets shorter posteriorly through the trunk region; (2) obsolete to absent epizygapophyseal spines; (3) vertebrae that are approximately as wide as they are long; and (4) dorsally convex subcentral ridge in lateral view (Holman, 1973). Remarks. The delicate neural spine and invariably thin hemal keel is similar to that found in other North American colubrids such as Coluber or Masticophis. However, Salvadora can be identified separately from those taxa on the basis of a proportionally shorter vertebra that appears to be nearly as wide as it is long, whereas the other two taxa appear elongate, more dorsally convex subcentral ridges, and obsolete to absent epizygapophyseal spines. Pantherophis, Pituophis, and Lampropeltis possess more robust and relatively wider vertebrae with less delicate neural spines and broader hemal keels than those of Salvadora. Jurestovsky (2021) also noted that extant Salvadora differ from Carphophis, Diadophis, and Gyalopion in possessing longer, more pointed accessory processes and a uniformly thinner hemal keel. Carphophis also possesses a narrower zygosphene, more elongate centrum, a shorter neural spine, less laterally directed postzygapophyses, and a less dorsoventrally tall cotyle (Jurestovsky, 2021). Salvadora has less robust postzygapophyses than Diadophis and possesses a more elongate centra, a taller neural spine, and a dorsoventrally taller cotyle than in Gyalopion (Jurestovsky, 2021).