Siberian ginkgo (Ginkgoites sibirica)

Ginkgoites sibirica Fossil Profile and Paleobotany

Widespread fossil records of Ginkgoites sibirica document the vast geographic distribution of ancient gymnosperms across Mesozoic Eurasia. First described from Siberian deposits, this species is one of the most common representatives of its genus in the Jurassic period. Its abundance in coal-bearing formations suggests it played a major role in peat-forming swamp forests.

The fossils are critical for understanding the transition of terrestrial ecosystems from the Jurassic to the Early Cretaceous. Researchers frequently utilize these leaf compressions for paleotemperature reconstructions. This taxon demonstrates a high tolerance to seasonal temperature variations in high-latitude environments.

Taxonomy

Morphology

The foliage of Ginkgoites sibirica is characterized by a deeply segmented, fan-shaped lamina with a long petiole. Each leaf is typically divided by a deep median sinus into two symmetrical halves, which are further split into narrow lobes. The venation consists of dense, dichotomously branching veins ending at the rounded apex of each lobe.

  • Leaf Division: Distinctly bilobed and further segmented into four to twelve lobes.
  • Venation Density: High density of parallel, forking veins throughout the blade.
  • Stomatal Type: Hypostomatic distribution with haplocheilic stomatal complexes.

Interesting facts

This species was originally named by the Swiss paleobotanist Oswald Heer in the 19th century based on Siberian collections. Leaf fossils are so abundant in some coal mines of Russia and China that they form entire layers within the rock. Its leaf shape closely resembles the modern Ginkgo biloba, illustrating remarkable morphological stasis over millions of years.

Geography of distribution

  • Russland (Sibirien)
  • Mongolei
  • China

Sources

  • GBIF Backbone Taxonomy (gbif.org)
  • The International Fossil Plant Names Index (ifpni.org)
  • Mesozoic Paleobotany of Eurasia