Monday, February 25, 2008
Ammonoids & Nautiloids
Ammonites are a form of ammoniod distinguished by there complex suture lines. They were abundant and diverse in the seas of the Mesozoic Era, and they evolved very rapidly to produce numerous species and genera. After a decline in diversity during the late Cretaceous period, ammonites became extinct at the same time as other marine groups, such as belemnites, and terrestrial groups such as dinosaurs. As both ammonites and there close relatives are both extinct scientists know very little about their mode of life. What is known about ammonites has been worked out mostly from experiments with model shells in water tanks.
The first 3 pictures are of some of my own ammonite fossils, and the fourth one is a picture of there modern relative the nautilus. The nautilus live deep under water at day usually scavenging on the bottom of the seabed but at night they will rise up to the shallower parts and hunt for prey, nautilus are disappearing by day because there beautiful shells are being sold to tourists if you see a nautilus in the wild its rare and you should think of yourself as very lucky because eventually tourism is going to wipe them out.