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Dr Herbert Klinger
Curator:
Cretaceous Invertebrate Collections
Natural History Department
Iziko South African Museum
Box 61, Cape Town 8000
South Africa
Phone: +27 (0)21 481 3875
Fax: +27 (0)21 481 3993
e-mail: hklinger@iziko.org.za Ammonites are extinct, probably squid-like animals that
had an external shell that was used for flotation. They are a very
useful group to use in dating geological sediments because
of their rapid rate of evolution, sometimes as little as 0,5 million
years, coupled with a wide geographic distribution.
The main objective of this research
programme is to fully describe the ammonite faunas from southern
Africa, to compare them with similar faunas from other parts of the world, and
to compile a detailed geological calendar based on the ammonite
succession. The ultimate aim is to compile a series of atlases
to fully illustrate the ammonite faunas from southern Africa, and to integrate the ammonite biozonation with zonations
based on other faunas and floras as well as chemical signatures.
The main focus of this work is
on the Cretaceous system in KwaZulu-Natal and the Eastern
Cape.
The Cretaceous Period was a very interesting time in the history
of the earth, from both a geological and a biological point of view.
Events of special interest included the opening of the Atlantic
Ocean, a world-wide
mid-Cretaceous anoxic event, culminating in a mass extinction at
the end of the Period. Since initiation of the project in 1966,
the area has been mapped in detail, stratigraphic sections were
measured at approximately 180 localities, and the systematic description
of the fossils is ongoing. Interesting faunal similarities were
found in part with the Caucasus region of Georgia, Patagonia, Madagascar, and the Gosau Basin of Austria.
The ammonites became extinct at
the end of the Cretaceous Period. Reasons for the extinction are
varied; at present the impact theory is the most popular.
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