Ammonoidea - Wikipedia
WEBAmmonoids are extinct spiral shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) than they are to shelled nautiloids (such as the living Nautilus). [1]
2.3 Ammonoidea - Digital Atlas of Ancient Life
WEBAmmonoidea, or ammonoids, constitute one of the most important clades of extinct invertebrate animals. Their lovely shells have long made them favorites of collectors and their fossils have been known since ancient times.
Fossil Focus: Ammonoids - PALAEONTOLOGY[online]
WEBAmmonoids (Ammonoidea) are an extinct group of marine invertebrates with an external shell. They were cephalopods, and hence closely related to modern cuttlefish, squid, octopuses and the pearly nautilus.
Ammonites, facts and photos - National Geographic
WEBWith squidlike tentacles extending from their distinctive multichambered shells, the extinct marine predators known as ammonites were once among the most successful and diverse animals on Earth.
Ammonoidea - Paleontology World
WEBAmmonoids are an extinct group of marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs are more closely related to living coleoids (i.e., octopuses, squid, and cuttlefish) than they are to shelled nautiloids such as the living Nautilus species.
What Is An Ammonite? - Natural History Museum
WEBThe Ammonoidea are ancient cephalopods that are closely related to the modern day chambered Nautilus, cuttlefish (e.g. the Cretaceous Actinosepia canadaensis), octopus, and squid. Their unique, chambered shell shapes have fascinated collectors as well as scientists who use ammonites as index fossils to date the relative age of rocks in which ...
Ammonoid | Mesozoic, Extinct, Shell | Britannica
WEBAug 6, 2024 · ammonoid, any of a group of extinct cephalopods (of the phylum Mollusca), forms related to the modern pearly nautilus (Nautilus), that are frequently found as fossils in marine rocks dating from the Devonian Period (began 419 million years ago) to the Cretaceous Period (ended 66 million years ago).