Frank Wesselingh |
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MSc-thesis
1993, title: “On the systematics of Miocene aquatic mollusks from Los Chorros
(dept. Amazonas, Colombia) and Nuevo Horizonte (dept. Loreto, Peru), with
comments on palaeoenvironment and palaeogeography”.
Currently
employed as a curator of the division of Cenozoic Mollusca at the
Nationaal
Natuurhistorisch Museum, Leiden, The Netherlands and a PhD-student, financed
by the Academy of Finland, at the Biodiversity Centre,
University of Turku,
Turku, Finland. The Promotion is due to take place in 2005.
The
Pebas Formation of Miocene Western Amazonia is incredible rich in very
well preserved molluscs. The fauna is mostly aquatic (>99% of the estimated
abundance), endemic and extinct. The fauna points to long-lived lacustrine
paleoenvironments during deposition. Lake Pebas was at its maximum over
1.1. million square kilometres. It originated in the latest Oligocene in
the Magdalena-Llanos Basins of Colombia, and gradually expanded eastward
and separated into a northern Llanos and Southern Pebas (or Western Amazon)
Basin. Lake Pebas was terminated by the tectonically induced uplift of
western Amazonia and the formation of the modern eastward flowing Amazon
river, c. 8 million years ago. During the time interval between 25 and
8 million years ago, the Pebas fauna radiated, and experienced episodically
faunal exchange with fauna’s from Venezuela. Aim of the research is to
reconstruct paleoenvironments in Miocene Western Amazonia, to establish
a stratigraphical framework, to deal with evolution of the Pebas fauna
and to establish biogeographical affinities of the fauna.