Headonium
The Headonium is a European land mammal zone of the Upper Eocene . Towards her end, she is hit by the Grande Coupure .
designation
The Headonium is named after Headon Hill on the west coast of the Isle of Wight (near Totland ). The hill is the type locality of the Headon Hill Formation .
stratigraphy
The European land mammal zone ( Engl. European Land Mammal Mega zone or ELMMZ , earlier still ELMA ) of Headoniums following the Robiacium and in turn from Suevium replaced. It contains the biozones MP 17A , MP 17B , MP 18 , MP 19 and MP 20 (MP stands for Mammal Paleogene ). Their basis is characterized by the first appearance (English. First Appearance Date or FAD ) of the mammalian taxon Isoptychus euzelensis . The end of the zone is defined by the extinction ( Last Appearance Date or LAD ) of the mammal family Amphimerycidae ( camel-like ). Equivalent land mammal zones of other continents are the Chadronium in North America , the Barrancum and Mustersum in South America and the Ulangochuium and the Ergilium in Asia .
Fossils
The headonium is characterized in particular by the first appearance of various Palaeotherium species (original equine species), including P. magnum , P. villerealense , P. curtum and P. medium . Furthermore, the Cricetidae (hamster-like) and the Castoridae (beaver) appear for the first time. Towards the end of the zone, the early pig-like entelodon appears .
In the course of the headonium die out:
- the taxa Quercygale (original predator), Isoptychus euzelensis (early rodent) and the Palaeotheria (early equine) Lophiotherium as well as the species P. villerealensis , P. curtum and P. medium belonging to Palaeotherium .
- the camel-like families of the Xiphodontidae and Amphimerycidae .
Age
The Headonium coincides with the Priabonium , the land mammal zone can thus be assigned an absolute age of 37.2 to 33.9 million years BP . In the North American land mammal ages (NALMA) it corresponds to the Chandronium .
literature
- Fahlbusch, V .: Report on the International Symposium on Mammalian Stratigraphy of the European Tertiary . In: Newsletters on Stratigraphy . tape 5 . Munich April 11, 1975, p. 160-167 .
- Savage, DE & Russell, DE: Comments on mammalian paleontologic stratigraphy and geochronology: Eocene stages and mammal ages of Europe and North America . In: Géobios Memoires Spéciales . tape 1 , 1977, pp. 47-56 .
- Schmidt-Kittler, N .: International Symposium on Mammalian Biostratigraphy and Paleoecology of the European Paleogens . In: Munich Geoscientific Treatises . A 10. Mainz February 1987, p. 1-312 .
- Gradstein, Ogg, J. & Smith, A .: A Geologic Time Scale 2004 . Ed .: Cambridge University Press. 2004, ISBN 0-521-78673-8 .