Hochuli
Fakultäten » Mathematisch-naturwissenschaftliche Fakultät » Paläontologisches Institut und Museum » Prof. Dr. Peter Andreas Hochuli » Hochuli
Current research project
| Title / Titel | Timing of angiosperm evolution | ||||
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| Abstract (PDF, 14 KB) | |||||
| Summary / Zusammenfassung | The record of angiosperm pollen from the stratigraphically oriented research project on Early Cretaceous sediments of southern Portugal (Heimhofer et al. 2004; Burla et al., in prep.) represent the most continuous and best dated angiosperm pollen record of the late Barremian to middle Albian interval (127 – 105 my). This record is independently dated by chemostratigraphy (C- and Sr isotope data) and biostratigraphy. These data now serve as a base for calibrating other records from mid-latitudes, including the richest mesofossil sites in Portugal and Eastern North America (Heimhofer et al. 2005). The comparison of our new data with the classical succession of the Potomac Group resulted in new age model for the latter, revealing major hiati and providing the first reliable timing of the major radiation events in the Aptian/Albian interval. Our data also reveal a new, so far essentially ignored, phase of angiosperm radiation (Hochuli et al., in press). Pre-Cretaceous records of angiosperms are essentially based on finds of pollen grains. Well preserved and diverse assemblages of angiosperm-like pollen grains have been described from the Middle Triassic of the Barents Sea (Hochuli & Feist-Burkhardt, 2004). A more detailed morphological study of these grains is planned for a better understanding of their origin and possible relationship. We follow up on our study on interference between changes in physical environment (climate sea level changes). Our results suggest an interrelation between the radiation of angiosperms and the relatively stable greenhouse climate of the Albian (Heimhofer et al. 2005). A continental section of Early Aptian age has been studied from the Ruhr area. It represents an infill of a karst structure in Paleozoic rocks containing abundant vertebrate fossils. The assemblage of rare angiosperm pollen is comparable to other Early Aptian sections (Portugal and Eastern US). However, the composition of the bulk of the assemblages suggests quite different climatic conditions, which are in line with the typical North Laurasian floral province. |
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| Publications / Publikationen | Heimhofer, U., Hochuli, P., Burla, S., Dinis, J., Weissert, H., 2005. Timing of Early Cretaceous angiosperm diversification and possible links to major paleoenvironmental change. Geology 33, 141-144.Hochuli, P.A. & Feist-Burkhardt, S. (2004) A boreal early cradle of Angiosperms? Angiosperm-like pollen from the Middle Triassic of the Barents Sea (Norway). J. Micropalaeontol., 23: 97-104.Hochuli, P. A., Heimhofer, U. & H. Weissert, H. (2006) Timing of early angiosperm radiation – Recalibrating the classical succession. J. Geol. Soc., London, 163: 587-594Hochuli, P.A. (2006) Timing of angiosperm evolution - the key role of stratigraphy. Fourth Swiss Geoscience Meeting, Bern 2006: 91-92.HEIMHOFER, U., HOCHULI, P. A., BURLA, S., & H. WEISSERT, H. (2007) New records of Early Cretaceous angiosperm pollen from Portuguese coastal deposits: Implications for the timing of the early angiosperm radiation. Review of Palaeobotany and Palynology, 144: 39-76.HEIMHOFER, U.; HOCHULI, P. A.; BURLA, S.; WEISSERT, H. (2007) The early evolution of angiosperms – a stratigraphic perspective. Geophysical Research Abstracts, Vol. 9, 03688, 2007.-HEIMHOFER, U. & HOCHULI, P.A. (2010) Early Cretaceous angiosperm pollen from a low-latitude succession (Araripe Basin, NE Brazil). Review of Palaeobotany and Palynology, 161: 105-126. | ||||
| Keywords / Suchbegriffe | Angiosperms, Cretaceous, Stratigraphy, Evolution, Palynomorphs | ||||
| Project leadership and contacts / Projektleitung und Kontakte |
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| Funding source(s) / Unterstützt durch |
Universität Zürich (position pursuing an academic career), Other Public Sources (e.g. Federal or Cantonal Agencies) |
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| In collaboration with / In Zusammenarbeit mit |
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| Duration of Project / Projektdauer | Mar 2000 to Dec 2012 |