Acanthopteris is a fossil fern genus that was established by H.C. Sze in 1931 based on leaf remains from the Lower Cretaceous of the Fuxin Basin in Liaoning Province, China. Traditionally, Acanthopteris is considered to belong to the tree fern family Dicksoniaceae and has been mainly found in the Lower Cretaceous of Fuxin Basin, Huolinhe Basin, and other coeval basins in Northeast China. Since this genus was founded, five fossil species have been described, including A. gothani Sze, A. acutata (Samylina) Zhang, A. alata (Fontaine) Zhang, A. onychioides (Vassilevskaja et Kara-Mursa) Zhang, and A. szei Cao. Based on the investigations on the newly collected fossil specimens and the examinations of other specimens, a reassessment of the systematics and fossil record of Acanthopteris is performed by using both morphological and cluster analysis approaches. The emendation of generic diagnosis of Acanthopteris is provided herein. Geographically, Acanthopteris shows limited distribution in North and NE China, Siberia, Russia and the Inner Zone of Japan. Temporally, Acanthopteris is restricted to the AptianAlbian period, representing a climate index fossil for a warm and humid climate condition of tropical to subtropical zones during the Early Cretaceous. (c) 2024 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.