Evidence from “Köppen signatures” of fossil plant assemblages for effective heat transport of Gulf Stream to subarctic North Atlantic during Miocene cooling – 2013

Authors: Thomas Denk , Guido W. Grimm , Friðgeir Grímsson, Reinhard Zetter. Shallowing of the Panama Sill and the closure of the Central American Seaway initiated the modern Loop Current–Gulf Stream circulation pattern during the Miocene, but no direct evidence has yet been provided for effective heat transport to the northern North Atlantic during that time. [...]

By | December 6th, 2013|Publications|0 Comments

Diverse fossil Onagraceae pollen from a Miocene palynoflora of north-east China: early steps in resolving the phytogeographic history of the family – 2012

Authors: Friðgeir Grímsson, Reinhard Zetter, Qin Leng The origin and evolution of angiosperms can be unravelled by using fossil records to determine first occurrences and phytogeographic histories of plant families and genera. Many angiosperm families, for example the Onagraceae, have a poor macrofossil record, but are more common in palynological records. Modern Onagraceae produce pollen [...]

By | March 17th, 2012|Publications|0 Comments

Morphological trends in the fossil pollen of Decodon and the paleobiogeographic history of the genus – 2012

Authors: Friðgeir Grímsson, David K. Ferguson, Reinhard Zetter Various pollen morphotypes of Decodon from the Cenozoic of North America, Europe, and Asia are described for the first time, using a combination of LM and SEM. The report includes the earliest pollen record of Decodon from the Northern Hemisphere. The pollen grains were obtained from sedimentary [...]

By | March 3rd, 2012|Publications|0 Comments

Fagaceae from the early Oligocene of Central Europe: Persisting new world and emerging old world biogeographic links – 2012

Authors: Thomas Denk, Friðgeir Grímsson, Reinhard Zetter Dispersed pollen from phosphoritic nodules of early Oligocene age from Cospuden (Rupelian, Saxony, Central Europe) comprises six distinct types of Fagaceae belonging to four to five genera, three of which belong to extinct lineages. Eotrigonobalanus and Trigonobalanopsis have stratigraphic ranges from the Eocene to the Miocene and the Pliocene, [...]

By | January 1st, 2012|Publications|0 Comments

Lythrum and Peplis from the Late Cretaceous and Cenozoic of North America and Eurasia: New evidence suggesting early diversification within the Lythraceae – 2011

To fully understand the evolution of today’s angiosperms, the fossil record of plant families and genera must be used to determine their time of origin and phytogeographic history. As within many angiosperm families, the interrelationships of extant Lythraceae are hard to resolve without sufficient data from the geological past. Here we establish the earliest fossil [...]

By | December 29th, 2011|Publications|0 Comments

Combined LM and SEM study of the Middle Miocene (Sarmatian) palynoflora from the Lavanttal Basin, Austria: Part II. Pinophyta (Cupressaceae, Pinaceae and Sciadopityaceae) – 2011

Authors: Friðgeir Grímsson, Reinhard Zetter The palynoflora from the Lavanttal Basin is characterised by a diverse spectrum of conifers. Their pollen is mostly well preserved allowing for high taxonomic resolution. Most coniferous taxa belong to the Pinaceae (Abies, Cathaya, Cedrus, Keteleeria, Larix, Picea, Pinus and Tsuga) and the Cupressaceae (Cryptomeria, Glyptostrobus and Sequoia), but pollen [...]

By | December 24th, 2011|Publications|0 Comments

Combined LM and SEM study of the Middle Miocene (Sarmatian) palynoflora from the Lavanttal Basin, Austria: Part I. Bryophyta, Lycopodiophyta, Pteridophyta, Ginkgophyta, and Gnetophyta – 2011

Authors: Friðgeir Grímsson, Reinhard Zetter, Christian Baal Preliminary studies of the palynoflora from the Lavanttal Basin show a relatively rich assemblage of pollen and spores. The palynoflora comprises at least 17 different kinds of spores, representing the Bryophyta (Sphagnum), Lycopodiophyta (Lycopodium, Selaginella), and the Pteridophyta (Dryopteris, Osmunda, Pteris), about 20 different pollen types of conifers [...]

By | December 24th, 2011|Publications|0 Comments

Art meets science – the unpublished drawings by Carl Hedelin and Thérèse Ekblom – 2011

Authors: Thomas Denk, Friðgeir Grímsson, Reinhard Zetter, Leifur A. Símonarson At the end of the nineteenth century, Alfred Gabriel Nathorst (1850–1921), then professor of palaeobotany in Stockholm, planned a major investigation of plant fossils from Iceland. This work was, however, put aside and not revived before his death. What remained was a set of more [...]

By | December 15th, 2011|Publications|0 Comments

Climate evolution in the northern North Atlantic – 15 Ma to present – 2011

Authors: Thomas Denk, Friðgeir Grímsson, Reinhard Zetter, Leifur A. Símonarson This chapter evaluates climatic signals from floras of 11 sedimentary rock formations from Iceland spanning the time interval 15–0.8 Ma. From 15 to 12 Ma, the climate was humid warm temperate probably with hot summers (Cfa climate) as evidenced by the presence of taxodiaceous conifers such [...]

By | December 12th, 2011|Publications|0 Comments

The biogeographic history of Iceland – the North Atlantic land bridge revisited – 2011

Authors: Thomas Denk, Friðgeir Grímsson, Reinhard Zetter, Leifur A. Símonarson Plants lacking long distance dispersal mechanisms required a functioning land bridge to colonize Iceland, a route provided by the North Atlantic Land Bridge (NALB). During the Cainozoic, the NALB, also referred to as the Thulean route, came into existence in the latest Paleocene and Early Eocene, [...]

By | December 11th, 2011|Publications|0 Comments