Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade …

The subclass Ammonoidea, a group that is often referred to as ammonites, first appeared about 450 million years ago. Ammonoidea includes a more exclusive group called Ammonitida, also known as …

Ammonoids (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 …

Nov 11, 2025 · 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 …

Ammonoidea, 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 …

Jul 28, 2025 · They are classified as the subclass Ammonoidea. These animals were free-swimming predators that navigated ancient seas. Their fossils are found globally in marine sedimentary rocks. …

Jul 6, 2023 · Ammonites belong to the subclass Ammonoidea, part of the larger class Cephalopoda, which also includes modern squid, octopus, and cuttlefish. Their closest living relative today is the …