Detroit Mi Brazilian Wax

of life of the ammonites
















Wien / Graz (fossil-world) - A team led by Alexander Luke Eder and Mathias Harzhauser (Natural History Museum Vienna), Werner Piller and Stefan Müllegger (Karl-Franzens University Graz) have succeeded to decode by using modern isotopic methods unclear to this day life and the development of ammonites, fossil squid relatives.

ammonites are among the most famous fossil marine organisms. 400 million years ago, in the age of Devon, were the first ammonites. Flourished experienced these molluscs but only in the Mesozoic era between 250 and 65 million years ago. They themselves were chased by giant dinosaurs such as marine or Mosasaurus plesiosaur. For more than 350 million years ammonites dominated the primordial sea. Together with a variety of other animals, they died at the end of the Mesozoic. The meteorite impact at the turn of the Cretaceous to Cenozoic about 65 million years ago that killed the dinosaurs to the victim, was the final crushing blow, and led to the extinction of ammonites.

The researchers showed for the first time that the fossil relatives of the squid in the course of her life lived at different depths and different specialized habitats of the Ur-Oceans. In this context, migrations were from shallow water into deep water and are discovered vice versa. Main reasons for the different development paths and trails in ammonites are the sexual maturity and reproductive cycles with concurrent dietary changes. The researchers analyzed the

oxygen and carbon isotopes of the ammonite shells. These grow throughout the life cycle of an animal and draw attention to the prevalent isotope ratios of seawater. This can be inferred sea temperatures and food supply.

Since the Schalenaragonit is mostly converted over millions of years and go into calcite, the isotopic signatures are lost in such old Aragonitschalen from the age of the dinosaurs a great rarity.

The results were published in the latest edition of the internationally renowned journal Earth and Planetary Science Letters (EPSL, Elsevier) published.