Sprecher
Beschreibung
Ginkgoales were an important component of Mesozoic floras, yet their modern diversity is restricted to the single living species Ginkgo biloba L. The long evolutionary history and conservative leaf architecture of this group make fossil ginkgoaleans valuable for exploring plant diversity, morphological persistence and environmental adaptation through geological time. Here, we present a systematic and morphometric study of Early–Middle Jurassic ginkgoalean fossils from the Dameigou area and nearby localities in the Qaidam Basin, northwestern China.
A total of 128 specimens from eight fossil-bearing horizons were examined, with emphasis on three common genera: Ginkgoites, Baiera and Sphenobaiera. By integrating macro-morphological observations, cuticular characters and multivariate analyses of measurable leaf traits, ten species are recognised from the studied succession. The results demonstrate that ginkgoaleans were taxonomically and morphologically diverse in the Qaidam Basin during the Early–Middle Jurassic. Quantitative analyses further show that leaf macrocharacters can support genus-level classification, especially for specimens without preserved cuticles, although species-level identification remains difficult because of overlapping leaf forms and possible heterophylly. In contrast, epidermal and cuticular features provide additional evidence for refining taxonomic assignments.
Several species, including Ginkgoites qaidamensis (Li) Zhang & Wang, G. longifolius Harris and Sphenobaiera spectabilis (Nathorst) Florin, occur across multiple stratigraphic levels and show limited morphological change through time. This pattern suggests a degree of morphological stability among Jurassic ginkgoaleans, even under changing local environmental conditions. Overall, the Qaidam material provides an important record for understanding the diversity, classification and evolutionary resilience of Ginkgoales during the Early–Middle Jurassic.