Pan-trionychids are a group of aquatic turtles with a geological occurrence from the Early Cretaceous to the present. Here, we report a small pan-trionychid specimen from the Upper Cretaceous Zhoutian Formation of the Ganzhou Basin of Jiangxi Province, China, which consists of a nearly complete carapace and several associated fragments. The specimen is the first definitive pan-trionychid record from the Upper Cretaceous of southern China. Its general skeletal features are comparable with those of other pan-trionychids from the mid Cretaceous of Asia. However, because the specimen appears to be a juvenile and lacks sufficient anatomical details, we refrain from naming a new species or hypothesizing phylogenetic relationships. Upper Cretaceous sediments in the Ganzhou Basin document a succession of turtle faunas ranging from aquatic pan-trionychids to semi-aquatic lindholmemydids to possibly terrestrial nanhsiungchelyids, but the relationship between this succession and paleoclimate remains ambiguous.

Key words: Pan-Trionychidae, Ganzhou Basin, Cretaceous, Zhoutian Formation, China.

Yuzheng Ke [key1480@163.com; ORCID: https://orcid.org/0000-0002-3728-898X], School of Earth Sciences, China University of Geosciences (Wuhan), Wuhan 430074, China. Department of Geosciences, University of Fribourg, 1700 Fribourg, Switzerland. Fenglu Han [hanfl@cug.edu.cn; ORCID: https://orcid.org/0000-0003-3399-4008] (corresponding author), School of Earth Sciences, China University of Geosciences (Wuhan), Wuhan 430074, China. Walter G. Joyce [walter.joyce@unifr.ch; ORCID: https://orcid.org/0000-0003-4726-2449], Department of Geosciences, University of Fribourg, 1700 Fribourg, Switzerland.