Authors: Thomas Denk, Friðgeir Grímsson, Reinhard Zetter, Leifur A. Símonarson

Terrestrial fossils from Late Miocene sediments in the Mókollsdalur area are mainly known for their insect fauna. Plant fossils and the sedimentological context suggest that most of the macrofossils deposited at Mókollsdalur originate from trees and shrubs that grew on the slopes around a caldera lake in the highlands. Abundant fossils of aquatic crustaceans, insects, and plants suggest that the lake and adjacent areas were a diverse ecosystem at the time of deposition. Forests covering the slopes were dominated by Fagus with a few evergreen elements in the understorey (IlexRhododendron). In contrast, the palynological record points to the presence of mixed oak forests in areas behind the mountain ridge surrounding the caldera. The poor representation of herbaceous elements in the pollen record may point to a filter effect against pollen influx from surrounding areas into the lake. Slope exposure may have determined the presence of Fagus or Quercus as is also seen today in cool temperate regions of the northern hemisphere. Overall, the climate appears to be more diversified than in the older floras with relatively warmer humid conditions windward of the mountains or in sheltered areas close to the lake and cooler more continental conditions leeward of the mountains.

Resources Link