The Dicksoniaceae is a representative member of the fern clade and shows high diversity during the Jurassic and Cretaceous in the Mesozoic, including Coniopteris Brongniart, Acanthopteris Sze, Eboracia Thomas of the extinct taxa, as well as Dicksonia L'Hér. and Lophosoria Presl of the extant taxa. This represents one of the significant plant groups for exploring the climate and environmental changes during the Mesozoic and modern times.
Acanthopteris is a fossil genus belonging to the tree fern family Dicksoniaceae. It 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. Although there are some documents on fossil Acanthopterisduring the past nine decades, our understandings on fossil record,diversity, tempo-spatial distribution and palaeoclimate natures ofthis fossil taxon are still limited.
A research team led by Prof. Wang Yongdong from the Nanjing Institute of Geology and Paleontology, Chinese Academy of Science, has reported their recent studies on the reassessment of systematics and fossil record of Acanthopteris by using both morphologicaland cluster analysis approaches and further discuss itspalaeogeographic distribution pattern as well as palaeoclimaticimplications. This report was recently published in the international journal “Cretaceous Research”.
Re-investigations were carried out based on newly collected fossil sterile and fertile specimens (Fig.1) and referring all published fossil recordsof Acanthopteris. Since this genus was founded, five valid fossil species have been recognized according to the emendation of generic diagnosis of Acanthopteris, including A. gothani Sze, A. acutata (Samylina) Zhang, A. alata (Fontaine) Zhang, A. onychioides (Vassilevskaja et Kara-Mursa) Zhang, and A. szei Cao (Fig.2).
It is suggested that Acanthopteris shows limited geographicaldistributionin North and NE China, Siberia and the Inner Zone of Japan, mainly in Northern Floristic Province in China. Compared to other period of the Cretaceous, Acanthopteris is temporally restricted to the Aptian-Albian periodof EarlyCretaceous, representing a climate index fossil taxon for a warm and humid climate condition of tropical to subtropical zones during the Early Cretaceousin northeastern Asia region (Fig.3). This result provides crucial fossil evidence for further investigating the Cretaceous floral evolution and greenhouse climate change in East Asia.
Yuan Meng, the co-trained master degree student from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) and Chengdu University of Technology is the first author, Wang Yongdong from NIGPAS is the corresponding author; Associate Professor Li Ya and Post Doc Zhang Li from NIGPAS, Associate Professor Cui Yiming from Lushan Botanical Garden, Chinese Academy of Science, and Prof. Zhou Xu from No. 101 Exploration Team Limited Liability Company of Northeast Coalfield Geology Bureau are co-authors of this study.
This research was supported by the National Natural Science Foundation of China, the Strategic Priority Research Program of the Chinese Academy of Sciences (B). Itis a contribution to IGCP 679.
Article information:Yuan M, Wang YD*, Zhou X, Li Y, Cui YM, Zhang L, 2024. The Early Cretaceous treefern Acanthopteris(Dicksoniaceae): New insight into fossil records, species diversity, palaeogeography and palaeoclimate. Cretaceous Research, 162, 105934. https://doi.org/10.1016/j.cretres.2024.105934
Fig. 1 Acanthopteris gothani Sze, specimens collected from the Early Cretaceous of Tiefa Basin, China. A, B, the sterile tripinnate frond, main rachis and pinnule arrangement; C-F. the fertile specimens showing pinnules, and sori arrangements
Fig. 2 The cluster analysis for five fossil species of Acanthopteris by UPGMA tree method
Fig.3 The palaeogeography distribution of fossil Acanthopteris in China and Siberia during the Early Cretaceous. The palaeogeography base maps are from Scotese (2021).
A. Type species Acanthopteris gothaniSze;
B. Five valid species of Acanthopteris. Different color of X refers to the five species, including Acanthopteris gothani Sze (blue); Acanthopteris acutata(Samylina)
Zhang (red);Acanthopteris alata(Fontaine) Zhang (green); Acanthopteris onychioides(Vassilevskaja et Kara-Mursa) Zhang (purple) and Acanthopteris szeiCao (orange ).
Download：