The lizard and snake fauna from the late middle–late Eocene (MP 16–MP 20) of Dielsdorf, near Zurich, Switzerland, is described comprehensively in this paper. Detailed comparisons of the Dielsdorf material with other extinct taxa allow us to establish a new species of the large “booid” genus Palaeopython, i.e., Palaeopython helveticus sp. nov., characterized by a unique combination of vertebral features, most prominently a highly vaulted neural arch. Other squamates of the Dielsdorf assemblage comprise the large lizard Palaeovaranus sp. and as many as three other taxa of snakes, i.e., Palaeopython cf. fischeri, Palaeopython sp. (morphotype 3), and “Booidea” indet. We conducted micro-CT scanning in the Palaeovaranus dentary, which confirmed the presence of plicidentine in this lizard genus. Micro-CT scanning was also conducted in differently sized snake vertebrae from our sample, revealing that the respective anatomical differences were probably due to ontogenetic variation. This is the first time that micro-CT scanning is applied in Palaeovaranus and Palaeopython. The importance of this method for potentially clarifying the taxonomy and precise affinities of extinct snakes is addressed. We also provide digital 3D model reconstructions of the Palaeovaranus dentary and Palaeopython vertebrae (including that of the holotype of Palaeopython helveticus sp. nov.) for the first time. The palaeobiogeographic significance of the Dielsdorf lizards and snakes is discussed and the sympatric occurrences of the genera Palaeovaranus and Palaeopython throughout the Eocene of Europe are presented in detail.

中文翻译：

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来自迪尔斯多夫始新世（瑞士苏黎世）的新古龟（Serpentes）和其他已灭绝的鳞茎

本文全面介绍了瑞士苏黎世附近迪尔斯多夫（Dielsdorf）中新世晚期（MP 16–MP 20）的蜥蜴和蛇类动物。通过对Dielsdorf材料与其他已灭绝的类群的详细比较，我们可以建立一个新的大型“ booid”属Palaeopython属，即Palaeopython helveticus sp。十一月，具有椎骨特征的独特组合，最突出的是高度拱形的神经弓。Dielsdorf组合的其他鳞茎包括大型蜥蜴Palaeovaranus sp。以及多达三个其他的蛇类群，即Palaeopythoncf。费舍里，Palaeopython sp。（字型3）和“ Booidea” inetet。我们在Palaeovaranus牙齿中进行了微CT扫描，证实了该蜥蜴属中存在plicidentine。还从我们的样本中对大小不同的蛇椎骨进行了微CT扫描，发现各自的解剖学差异可能是由于个体发育的差异所致。这是在Palaeovaranus和Palaeopython中首次应用微CT扫描。该方法对于潜在地阐明灭绝蛇的分类和精确亲和力的重要性已得到解决。我们还首次提供了Palaeovaranus牙齿和Palaeopython椎骨（包括Palaeopython helveticus sp。nov。的整型）的数字3D模型重建。讨论了狄尔斯多夫蜥蜴和蛇的古生物地理意义，并详细介绍了整个欧洲始新世Palaeovaranus和Palaeopython属的同生发生。揭示了各自的解剖学差异可能是由于个体发育变异。这是在Palaeovaranus和Palaeopython中首次应用微CT扫描。该方法对于潜在地阐明灭绝蛇的分类和精确亲和力的重要性已得到解决。我们还首次提供了Palaeovaranus牙齿和Palaeopython椎骨（包括Palaeopython helveticus sp。nov。的整型）的数字3D模型重建。讨论了狄尔斯多夫蜥蜴和蛇的古生物地理意义，并详细介绍了整个欧洲始新世Palaeovaranus和Palaeopython属的同生发生。揭示了各自的解剖学差异可能是由于个体发育变异所致。这是在Palaeovaranus和Palaeopython中首次应用微CT扫描。该方法对于潜在地阐明灭绝蛇的分类和精确亲和力的重要性已得到解决。我们还首次提供了Palaeovaranus牙齿和Palaeopython椎骨（包括Palaeopython helveticus sp。nov。的整型）的数字3D模型重建。讨论了狄尔斯多夫蜥蜴和蛇的古生物地理意义，并详细介绍了整个欧洲始新世Palaeovaranus和Palaeopython属的同生发生。这是在Palaeovaranus和Palaeopython中首次应用微CT扫描。该方法对于潜在地阐明灭绝蛇的分类和精确亲和力的重要性已得到解决。我们还首次提供了Palaeovaranus牙齿和Palaeopython椎骨（包括Palaeopython helveticus sp。nov。的整型）的数字3D模型重建。讨论了狄尔斯多夫蜥蜴和蛇的古生物地理意义，并详细介绍了整个欧洲始新世Palaeovaranus和Palaeopython属的同生发生。这是在Palaeovaranus和Palaeopython中首次应用微CT扫描。该方法对于潜在地阐明灭绝蛇的分类和精确亲和力的重要性已得到解决。我们还首次提供了Palaeovaranus牙齿和Palaeopython椎骨（包括Palaeopython helveticus sp。nov。的整型）的数字3D模型重建。讨论了狄尔斯多夫蜥蜴和蛇的古生物地理意义，并详细介绍了整个欧洲始新世Palaeovaranus和Palaeopython属的同生发生。我们还首次提供了Palaeovaranus牙齿和Palaeopython椎骨（包括Palaeopython helveticus sp。nov。的整型）的数字3D模型重建。讨论了狄尔斯多夫蜥蜴和蛇的古生物地理意义，并详细介绍了整个欧洲始新世Palaeovaranus和Palaeopython属的同生发生。我们还首次提供了Palaeovaranus牙齿和Palaeopython椎骨（包括Palaeopython helveticus sp。nov。的整型）的数字3D模型重建。讨论了狄尔斯多夫蜥蜴和蛇的古生物地理意义，并详细介绍了整个欧洲始新世Palaeovaranus和Palaeopython属的同生发生。