Fossil fruits of Trapa L. from the late Miocene of southeastern Qaidam Basin (Qinghai, China)

ABSTRACT

Trapa L. (Lythraceae J. ST.-HIL) is a genus of annual free-floating plant, widely distributed in the Northern Hemisphere. The Qaidam Basin is regarded as an ideal region to understand the Cenozoic palaeoclimatic and palaeobiological evolution of the northern Tibetan Plateau. A few records of Trapa have been previously mentioned from the Cenozoic deposits of the Qaidam Basin, northern Tibetan Plateau. Here, we describe some fossil fruits of Trapa from the late Miocene Shangyoushashan Formation of southeastern Qaidam Basin (Tuosu Lake area), which were identified as Trapa qaidamensis sp. nov. based on their morphology. Extant species of Trapa usually live in the environments with mean temperature of warmest quarter (MTWQ) ranging from 14.9°C to 30.9°C, as well as mean temperature of warmest month (MTWM) ranging from 19.6°C to 37.3°C in the living areas of Trapa. Compared with MTWQ 16.5°C and MTWM 17.5°C in current fossil locality, the present fossil site was warmer during the Miocene than in the present day.

urn:lsid:zoobank.org:act:9F7DAD1B-DA2D-4734-BE27-99276F57DD2A

Graphical Abstract

KEYWORDS:

• Trapa
• the Qaidam Basin
• late Miocene
• paleoclimate
• paleoelevation

Acknowledgments

We specially thank Prof. Bainian Sun (Lanzhou University, China) who delivered the fossil described herein to the authors.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/08912963.2022.2140045

Additional information

Funding

This work is supported by the Second Tibetan Plateau Scientific Expedition, Research Program [grant number 2019QZKK0704]; the National Natural Science Foundation of China [grant numbers 42172005 and 41272026]; the State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of Geology and Palaeontology, CAS) [193130].