Bolet Arnau, Delfino Massimo, Fortuny Josep, Almécija Sergio, Robles Josep M, Alba David M
Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain.
Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain; Dipartimento di Scienze della Terra, Università di Torino, Torino, Italy.
PLoS One. 2014 Jun 4;9(6):e98082. doi: 10.1371/journal.pone.0098082. eCollection 2014.
The evolution of blanid amphisbaenians (Mediterranean worm lizards) is mainly inferred based on molecular studies, despite their fossils are common in Cenozoic European localities. This is because the fossil record exclusively consists in isolated elements of limited taxonomic value. We describe the only known fossil amphisbaenian skull from Europe - attributed to Blanus mendezi sp. nov. (Amphisbaenia, Blanidae) - which represents the most informative fossil blanid material ever described. This specimen, from the Middle Miocene of Abocador de Can Mata (11.6 Ma, MN7+8) in the Vallès-Penedès Basin (Catalonia, NE Iberian Peninsula), unambiguously asserts the presence of Blanus in the Miocene of Europe. This reinforces the referral to this genus of the previously-known, much more incomplete and poorly-diagnostic material from other localities of the European Neogene. Our analysis - integrating the available molecular, paleontological and biogeographic data - suggests that the new species postdates the divergence between the two main (Eastern and Western Mediterranean) extant clades of blanids, and probably precedes the split between the Iberian and North-Western African subclades. This supports previous paleobiogeographic scenarios for blanid evolution and provides a significant minimum divergence time for calibrating molecular analyses of blanid phylogeny.
盲蛇蜥（地中海蚓蜥）的演化主要是基于分子研究推断出来的，尽管它们的化石在欧洲新生代地层中很常见。这是因为化石记录仅由分类价值有限的孤立骨骼组成。我们描述了欧洲唯一已知的化石盲蛇蜥头骨——归属于门德齐盲蛇新种（蚓蜥目，盲蛇科）——它代表了有史以来描述的最具信息价值的化石盲蛇材料。该标本来自伊比利亚半岛东北部加泰罗尼亚的巴列斯-佩内德斯盆地中中新世的卡恩马塔阿博卡多尔（1160万年前，MN7+8），明确证实了欧洲中新世存在盲蛇属。这进一步支持了将欧洲新近纪其他地区已知的、更不完整且诊断性较差的材料归为该属。我们整合现有分子、古生物学和生物地理学数据的分析表明，新物种形成的时间晚于现存两个主要盲蛇类分支（东地中海和西地中海）的分化时间，可能早于伊比利亚和西北非洲亚分支的分裂时间。这支持了之前关于盲蛇演化的古生物地理学假说，并为校准盲蛇系统发育的分子分析提供了一个重要的最小分化时间。
