Ammonites (Ammonoidea)

Palaeontologically, these animals are amongst the most important groups: they evolved rapidly and as a consequence they adopted a wide range of forms and shapes, which are often typical of a certain, comparatively short time interval. This, together with the fact that they were swimming organisms and were distributed over large distances, makes them excellent index fossils. Ammonites generally lived in spirally coiled shells. Their name derives from the Greek god Ammon, who was pictured as a man with the horned head of a ram. Pliny the Elder (died 79 BC near Pompeii) referred to these animals as 'ammonis cornua': horn of Ammon. Ammonites belonged to the 'nekton': the comparatively large, free-swimming organisms independent of coast and sea floor, living in the open ocean. Their mode of life compares fairly well with that of Nautilus, which occurs in modern tropical seas. Hoploscaphites is a typical species of the Maastricht Chalks. home | back | back to the tour