来自中国南雄盆地上白垩统的一个近乎完整的南雄龟科标本的分类学、形态学及系统发育学研究

Taxonomy, morphology, and phylogeny of a nearly complete nanhsiungchelyid specimen from the Upper Cretaceous of the Nanxiong Basin, China.

作者信息

Ke Yuzheng, Shi Zhongye, Tong Haiyan, Li Bicheng, Zhang Yunfei, Han Fenglu, Joyce Walter G

机构信息

School of Earth Sciences, China University of Geosciences (Wuhan), Wuhan, China.

Department of Geosciences, University of Fribourg, Fribourg, Switzerland.

出版信息

Swiss J Palaeontol. 2025;144(1):48. doi: 10.1186/s13358-025-00385-2. Epub 2025 Aug 5.

DOI:10.1186/s13358-025-00385-2

PMID:40778005

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC12325503/

Abstract

UNLABELLED

, the type genus of Nanhsiungchelyidae, is an extinct turtle taxon that lived during the Late Cretaceous in southern China. Despite having a relatively abundant fossil record, the plastral morphology of is not well understood. Here, we describe a large specimen of with an associated skull and shell (SNHM 1558) from the Upper Cretaceous of Nanxiong Basin, China. The skull of SNHM 1558 is similar to that of , but the carapace bears a pair of stick-like anterolateral processes. For this reason, we tentatively refer SNHM 1558 to cf. . A concave plastron and a narrower posterior lobe indicate that SNHM 1558 may be a male. spp. was previously regarded as the most advanced taxa of Nanhsiungchelyidae, but some morphological characteristics suggest plesiomorphic similarities with the outgroup spp. A phylogenetic analysis using spp. as the outgroup suggests that spp. and form a monophyletic group at the base of Nanhsiungchelyidae. However, this phylogenetic result is not conclusive, as spp. is found deeply nested within the tree when is employed as the outgroup.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1186/s13358-025-00385-2.

摘要

未标注

南雄龟科的模式属，是一种已灭绝的龟类分类单元，生活在晚白垩世的中国南方。尽管有相对丰富的化石记录，但南雄龟的腹甲形态仍未得到很好的理解。在此，我们描述了一个来自中国南雄盆地上白垩统的带有头骨和龟壳的南雄龟大标本（SNHM 1558）。SNHM 1558的头骨与南雄龟的相似，但背甲有一对棒状的前侧突起。因此，我们暂时将SNHM 1558归入南雄龟属未定种（cf. 南雄龟属）。腹甲凹陷且后叶较窄表明SNHM 1558可能是雄性。南雄龟属物种以前被认为是南雄龟科中最进化的分类单元，但一些形态特征表明与外类群满洲龟属物种有原始的相似性。以满洲龟属物种作为外类群的系统发育分析表明，南雄龟属物种和南雄龟形成了一个位于南雄龟科基部的单系群。然而，这个系统发育结果并不确凿，因为当以满洲龟作为外类群时，满洲龟属物种被发现在树中位置较深。