Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, College of Life Sciences, Sichuan University, Chengdu, PR China.
Mol Phylogenet Evol. 2010 Jul;56(1):252-8. doi: 10.1016/j.ympev.2009.12.011. Epub 2009 Dec 22.
The mysterious Asian hynobiid salamander, Protohynobius puxiongensis, was described based on a single specimen collected in 1965 and never found again since then. Because the specimen had an internasal bone, Pr. puxiongensis was thought to retain a primitive character lost by a common ancestor of all other hynobiid salamanders, and it was thus considered to be not only a new genus, but also a new subfamily. This conclusion bothered herpetologists for decades because it was based on only one specimen and one character without other living specimens being rediscovered. After years of field effort, we rediscovered living individuals of Pr. puxiongensis at its type locality. All characters observed in rediscovered specimens are identical to the original description of the holotype except the internasal bone, implying that the internasal bone observed in the holotype may be just an individual variation. To examine the phylogenetic position of Pr. puxiongensis, we sequenced complete mitochondrial genomes for this species, together with two Pseudohynobius species. By combining 18 published hynobiid mitochondrial genomes and our new sequences, we reconstructed a comprehensive phylogenetic relationship of Hynobiidae at the genus level. Our results indicate that Pr. puxiongensis is deeply nested within the hynobiid phylogeny. It is the sister group of the Pseudohynobius species, and the validity of subfamily Protohynobiinae is not supported.
神秘的亚洲小鲵属物种，赤水小鲵（Protohynobius puxiongensis），是基于 1965 年采集的唯一标本描述的，此后再也没有发现过。由于该标本具有鼻中隔，因此赤水小鲵被认为保留了所有小鲵属物种共同祖先失去的原始特征，因此它不仅被认为是一个新的属，也是一个新的亚科。这一结论困扰了两栖爬行动物学家数十年，因为它仅基于一个标本和一个特征，而没有其他活体标本被重新发现。经过多年的实地考察，我们在其模式产地重新发现了赤水小鲵的活体个体。除了鼻中隔之外，在重新发现的标本中观察到的所有特征都与模式标本的原始描述完全一致，这表明模式标本中观察到的鼻中隔可能只是个体变异。为了研究赤水小鲵的系统发育位置，我们对该物种的完整线粒体基因组进行了测序，同时还对两种拟小鲵属物种进行了测序。通过结合 18 个已发表的小鲵属线粒体基因组和我们的新序列，我们在属级水平上重建了小鲵科的综合系统发育关系。我们的结果表明，赤水小鲵在小鲵属的系统发育中处于较深的分支位置。它是拟小鲵属物种的姊妹群，而 Protohynobiinae 亚科的有效性不被支持。
