New Fagaceous pollen taxa from the Miocene Søby flora of Denmark and their biogeographic implications

• Premise: The Fagaceae comprise around 1000 tree species in the Northern Hemisphere.Despite an extensive fossil pollen record, reconstructing biogeographic patternsis hampered because it is difficult to achieve good taxonomic resolution withlight microscopy alone. We investigate dispersed pollen of Fagaceae from the Miocene Søby flora, Denmark. We explore the latitudinal gradient in Fagaceae distribution during the Miocene Climatic Optimum (MCO) in Europe and the Northern Hemisphere to compare it with the Eocene Warmhouse and the present.Methods: We investigated dispersed pollen using light and scanning electron microscopy. We assessed biogeographic patterns in Fagaceae during two warm periods in Earth history (MCO, Eocene) and the present.Results: Eight species of Fagaceae were recognized in the Søby flora. Of these, Fagus had a continuous Mediterranean to subarctic distribution during MCO; Quercus sect. Cerris and castaneoids had northern limits in Denmark, and evergreen Quercus sect. Ilex in Central Europe. In a northern hemispheric context, Fagus and sections of Quercus had more northerly distribution limits during Eocene and MCO with maximum northward extensions during Eocene (Fagus, castaneoids) or Oligo‐Miocene (Quercus sects. Cerris and Ilex). The known distribution of the extinct Tricolporopollenites theacoides during MCO included Central Europe and East China, while this taxon thrived in South China during Eocene.Conclusions: More northerly distributions during MCO and Eocene probably were determined by temperature. In contrast, fossil occurrences in areas that are arid or semi‐humid today were determined by maritime conditions in these areas (western North America, Central Asia) during the Cenozoic.

Subject headings

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Annan geovetenskap och miljövetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Other Earth and Related Environmental Sciences (hsv//eng)

Keyword

Fagus

Fususpollenites fusus

middle Miocene

Northern Hemisphere

paleobotany

paleopalynology

Quercus

scanning electron microscopy

Tricolporopollenites pseudocingulum

Tricolporopollenites theacoides

Ecosystems and species history

Ekosystem och arthistoria

The changing Earth

Den föränderliga jorden

Publication and Content Type

ref (subject category)

art (subject category)