Character state-based taxa erected to accommodate fossil and extant needle stoneflies (Leuctridae – Leuctrida tax.n.) and close relatives – 2015

Authors: Oliver Béthoux, Boris Kondratieff, Friðgeir Grímsson, Erling Ólafsson, Torsten Wappler In order to accommodate a newly discovered fossil specimen related to a subset of extant needle stoneflies (Leuctridae sensu Zwick, 2000), we provide a comparative analysis of the wing venation of these insects, and of their close relatives, primarily based on extant material. A [...]

By | April 24th, 2015|Publications|0 Comments

Fagaceae pollen from the early Cenozoic of West Greenland: revisiting Engler’s and Chaney’s Arcto-Tertiary hypotheses – 2015

Authors: Friðgeir Grímsson, Reinhard Zetter, Guido W. Grimm, Gunver Krarup Pedersen, Asger Ken Pedersen, Thomas Denk In this paper we document Fagaceae pollen from the Eocene of western Greenland. The pollen record suggests a remarkable diversity of the family in the early Cenozoic of Greenland. Extinct Fagaceae pollen types include Eotrigonobalanus, which extends at least back to [...]

By | February 24th, 2015|Publications|0 Comments

Evolutionary trends and ecological differentiation in early Cenozoic fagaceae of western North America – 2014

Authors: Johannes M. Bouchal, Reinhard Zetter, Friðgeir Grímsson, Thomas Denk The early Cenozoic was a key period of evolutionary radiation in Fagaceae. The common notion is that species thriving in the modern summer-dry climate of California originated in climates with ample summer rain during the Paleogene. We investigated in situ and dispersed pollen of Fagaceae [...]

By | August 24th, 2014|Publications|0 Comments

Before the ‘Big Chill’: A preliminary overview of arthropods from the middle Miocene of Iceland (Insecta, Crustacea) – 2014

Authors: Torsten Wappler, Friðgeir Grímsson, Bo Wang, André Nel, Erling Ólafsson, Alexey A. Kotov, Steven R. Davis, Michael S. Engel Well-preserved arthropods are reported from Miocene sedimentary rocks of the Skarðsströnd–Mókollsdalur (9–8 Ma) and Hreðavatn–Stafholt (7–6 Ma) Formations in Iceland. Fossil remains of terrestrial and/or freshwater animals have rarely been reported from the island before. Here [...]

By | May 24th, 2014|Publications|0 Comments

Aponogeton pollen from the Cretaceous and Paleogene of North America and West Greenland: Implications for the origin and palaeobiogeography of the genus – 2014

Authors: Friðgeir Grímsson, Reinhard Zetter, Heidemarie Halbritter, Guido W. Grimm The fossil record of Aponogeton (Aponogetonaceae) is scarce and the few reported macrofossil findings are in need of taxonomic revision. Aponogeton pollen is highly diagnostic and when studied with light microscopy (LM) and scanning electron microscopy (SEM) it cannot be confused with any other pollen types. [...]

By | January 15th, 2014|Publications|0 Comments

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