Fagaceous fossils from the Eocene Buchanan Lake Formation, Axel Heiberg Island, Canadian High Arctic
Author Block
Y. Liu1, J. F. Basinger
2;
1University of Wisconsin-Stevens Point, Stevens Point, WI, United States,
2University of Saskatchewan, Saskatoon, SK, Canada.
Abstract:
Fagaceous fossils represented by pollen, leaves, and cupule/nuts were recovered from middle Eocene Buchanan Lake Formation, Axel Heiberg Island, Canadian High Arctic. They are assigned to three extant genera, viz.
Castanea, Fagus, and
Quercus, and one unassignable taxon (Fagoideae gen. et sp. indet.). The first two genera are only represented by pollen, among which one pollen type of
Castanea and three pollen types of
Fagus were recognized, while the occurrence of
Quercus was supported by both pollen and leaves. On the basis of leaf and pollen morphology, the oak fossils are assigned to two sections of subgenus
Quercus, viz. sect.
Lobatae and sect.
Quercus. The unassignable taxon represents the cupule and nuts, displaying characters not in any extant fagaceous taxon, thus probably representing an extinct member of early Fagaceae lineage. All the fossils might be deciduous in nature, which is consistent with paleoclimate and paleofloristics, reconstructed from other evidence. The study shows that the
Fagus pollen are probably one of the earliest record and the red and white oaks would be differentiated as early as in the middle Eocene.
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