The skull osteology of Hierophis viridiflavus is here described and figured in detail on the basis of 18 specimens. The sample includes specimens from the ranges of both H. viridiflavus viridiflavus and H. viridiflavus carbonarius as well as specimens not identified at sub‐specific level. The main characters that define H. viridiflavus in comparison to the parapatric congeneric species Hierophis gemonensis are wide maxillary diastema, basioccipital crest well distinct in three lobes and basioccipital process well marked. The foramina of the otoccipital and prootic, and the basioccipital process of the basioccipital are among the most ontogenetically variable characters, as indicated by two juvenile specimens included in the sample. A specimen‐level phylogenetic analysis including H. gemonensis and other outgroups (overall 6 species, 26 specimens, 64 skull characters) recovered all H. viridiflavus specimens in one clade, indicating the presence of a clear phylogenetic signal in the applied characters. However, the resolution within the H. viridiflavus clade is poor the monophyly of H. viridiflavus carbonarius was retrieved, but not that of Hierophis v. viridiflavus. Probably due to the relatively high variability, the skull morphology does not support the recently proposed specific status of the two subspecies.

中文翻译：

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西方鞭蛇 Hierophis viridiflavus (Squamata, Colubridae) 的头骨骨学和骨学系统发育

此处根据 18 个标本详细描述和描绘了 Hierophis viridiflavus 的颅骨骨学。样本包括来自 H. viridiflavus viridiflavus 和 H. viridiflavus carbonarius 范围内的标本以及未在亚特异性水平上鉴定的标本。与旁缘同类物种 Hierophis gemonensis 相比，定义 H. viridiflavus 的主要特征是宽阔的上颌间隙、三叶明显不同的基底枕嵴和明显的基底枕突。样本中包含的两个幼年标本表明，耳枕和前体的孔以及基枕的基枕突是个体遗传变异最大的特征之一。标本级系统发育分析，包括 H. gemonensis 和其他外群（总共 6 个物种，26 个标本，64 个头骨字符）在一个进化枝中恢复了所有 H. viridiflavus 标本，表明在应用的字符中存在清晰的系统发育信号。然而，H. viridiflavus 进化枝内的分辨率很差，H. viridiflavus carbonarius 的单系被检索到，但不是 Hierophis v. viridiflavus。可能由于相对较高的变异性，头骨形态不支持最近提出的两个亚种的特定状态。