Current field work projects

1. Patagonia, Argentina. Project: Faunal changes across the K/T boundary in high latitudes (in cooperation with R. SCASSO und F. MEDINA, Buenos Aires, and M. ABERHAN und W. KIESSLING, Berlin.


The current knowledge of mass extinctions of macro-invertebrates at the K/T boundary is mainly based on studies of tropical and subtropical faunas. Extinction patterns in high latitudes are only well-documented in the Northern Hemisphere and Antarctica. The current project intends to (1) to get a complete documentation of faunistic and ecological patterns in the Maastrichtian, at the K/T boundary, and in the Danian of South America based on detailed field work; (2) perform quantitative-stratigraphic sampling that will enable a critical evaluation of events at the K/T boundary and to decide whether gradual, step-wise or sudden extinction is more likely; (3) analyse whether the observed extinction and recovery patterns can be explained with facies or climate changes, or with facies-independent causes (e.g. impact); (4) interpret the data in a global context and to decide whether biogeographic patterns and extinction at the K/T boundary are coupled.

Three field trips were conducted in the years 2002 - 2004 and a lot of data and abundant material was gathered.




Central Iberian Ranges, northeastern Spain. Project: Late Jurassic and Early Cretaceous selachian and actinopterygian faunas.

This project is dedicated to analyse Late Jurassic and Early Cretaceous fish faunas of the Iberian basin (northeastern Spain). Late Jurassic sedimentation of the Iberian basin (Central Iberian Ranges, NE Spain) occurred in shallow and extensive, gently inclined ramp settings (several hundred kilometres across), which were connected to the Tethys in the east, bordered by the Iberian Massif in the west and the Ebro Massif in the north. During major flooding episodes (e.g., middle Oxfordian, early Kimmeridgian), connections with the boreal realm were established across the so-called Soria seaway in the northwest. Early Cretaceous sedimentation occurred in three subbasins in north-eastern Spain (Aguilon, Aliaga, and Oliete subbasins), which are related to the anticlock-wise rotation of the Iberian Plate. Jurassic and Cretaceous fishes from the Iberian basin were, despite their abundance, only sporadically considered. This project started in 1996 in cooperation with the Dept. Ciencias de la Tierra, Universidad de Zaragoza (G. CUENCA-BESCOS). Since then, 25 Late Jurassic sections have been sampled and studied, ten of which yielded abundant and well-preserved material from the late Oxfordian to the early Tithonian, with most identifiable material coming from Kimmeridgian strata. In addition, five Early Cretaceous sections were analysed (three MSc-thesis were carried out on ostracodes, hybodontoid and neoselachian sharks). However, the full diversity is still unknown and further effort, in particular detailed and stratified sampling of selected sections from the west to the east of the Iberian basin and the three Early Cretaceous subbasins, is essential to more fully understand the diversity and evolutionary history of fishes of the Iberian Plate.

Field-work will continue in the second half of 2005. In the framework of a PhD project, which is financially supported by the DFG, a PhD- and a MSc-student will study Late Jurassic sections. The faunal compositions, migration routes, and prey preferences of Late Jurassic sharks will be analyzed using a multidisciplinary approach including isotopic analyses.