# Applying Flora Composition and Leaf Physiognomy to Reconstruct the Paleocommunity, Palaeoclimate, and Paleoenvironment of the Jehol Biota in Jilin, China

## TL;DR

This study uses plant fossils to reconstruct ancient plant communities and climate in China's Baishan Basin during the Early Cretaceous.

## Contribution

The study identifies the easternmost distribution of the Jehol Biota and provides new insights into Early Cretaceous paleoenvironments in East Asia.

## Key findings

- The Baishan flora includes 46 species grouped into four distinct plant communities.
- The region had a warm and humid temperate climate during the Early Cretaceous.
- The Baishan flora is confirmed as the easternmost extension of the Jehol Biota.

## Abstract

This study addresses the limited understanding of Early Cretaceous paleoflora in the Baishan Basin, Jilin Province, China. The research aimed to systematically analyze newly discovered plant fossils from the Yingzuilazi Formation to reconstruct the paleocommunity and paleoclimate. The findings identified 46 plant species, which were predominantly autochthonous or parautochthonous. The analysis allowed for the reconstruction of four distinct plant communities. Their floral composition indicated that the region experienced a warm and humid temperate climate during the Early Cretaceous. Furthermore, the high similarity with the famous Jehol Biota from western Liaoning confirmed the Baishan flora as its easternmost known distribution. These conclusions are significant for multiple reasons. They provide crucial data for understanding the Early Cretaceous floristic provincialism and paleoenvironmental reconstruction in East Asia. The study offers a geological benchmark for predicting how modern vegetation might respond to a future greenhouse climate. Finally, certain plant groups identified (Sphenopsida and Filicopsida) may serve as useful indicators for exploring the terrestrial shale oil and gas reservoirs from this period.

Herein, we present a systematic investigation of plant fossils from the Yingzuilazi Formation in Baishan City, Jilin Province, China. The Baishan flora comprises 27 genera and 46 species. They are predominantly autochthonous or parautochthonous, based on their floral composition and taphonomic attributes. An analysis of paleoecological characteristics of the fossil plant assemblages, combined with the habitat preferences of analogous modern communities, allowed us to reconstruct the Early Cretaceous plant communities in the Baishan Basin: a riparian–wetland community, lowland community, montane slope community, and montane highland community. The floral composition, a statistical analysis of foliar physiognomy, and the palynofloral characteristics indicated a warm and humid temperate climate during the deposition of the Yingzuilazi Formation. A genus-level comparison with the Yixian Formation flora of western Liaoning revealed high compositional similarity, which confirms the Baishan flora as the easternmost distribution of the Jehol Biota in China. This study provides new fossil evidence for understanding Early Cretaceous floristic provincialism and paleoenvironmental reconstruction in East Asia. It offers geological references that can predict vegetation responses to a greenhouse climate. Additionally, Sphenopsida and Filicopsida may serve as potential indicators that may identify favorable terrestrial shale oil and gas reservoirs from the Early Cretaceous.