Ammonitida or "True ammonites" are an order of ammonoid cephalopods that lived from the Jurassic through Paleocene time periods, commonly with intricate ammonitic sutures. Ammonitida is divided into four suborders, the Phylloceratina, Lytoceratina, Ancyloceratina, and Ammonitina.

Ammonoidea includes a more exclusive group called Ammonitida, also known as the true ammonites. These animals are known from the Jurassic Period, from about 200 million years ago. Most ammonites died out at the same time as the non-avian dinosaurs, at the end of the Cretaceous Period, 66 million years ago.

Ammonitida- the ammonites; The ammonites became extinct at the same time as the dinosaurs about 65 million years ago. Ammonites were so plentiful that paleontologists use them To date layers of rock.They have been found all over the world.

Ammonitida, Lower Jurassic – Upper Cretaceous; In some classifications, these are left as suborders, included in only three orders: Goniatitida, Ceratitida, and Ammonitida. Taxonomy of the Treatise on Invertebrate Paleontology

Ammonitida, Lower Jurassic – Lower Paleocene; In some classifications, these are left as suborders, included in only three orders: Goniatitida, Ceratitida and Ammonitida. The classification of ammonoids is based in part on the ornamentation and structure of the septa comprising their shells' gas chambers.

generally be called ammonites because they belong in the Order Ammonitida. Not all ammonoids are ammonites but all ammonites are ammonoids! This chart shows three of the more common orders of ammonoids throughout geologic time (modified from Kennedy in Hallam, 1977). Keep in mind not all of the ammonoid orders are represented in this

2013年6月13日 · Ammonites (Ammonitida) were shelled cephalopod molluscs that lived throughout the world’s oceans during the Mesozoic (Triassic, Jurassic and Cretaceous periods) and they were an extremely successful order, as evidenced by the frequency with which their remains are found.