![]() Exceptional trace fossils like the ‘zombie’ ammonite give us an incite into tiny moments of the geological past. Ammonite stomach and crop analysis suggests that bivalves, crustaceans, sea urchins, sea lilies (animals related to sea urchins and starfish) and other ammonites were what they fed on (Jager and Fraaye 1997). 1998) and it has been hypothesised that empty ammonite shells were the first group of molluscs that hermit crabs adapted to inhabit (Fraiije 2003). ![]() ![]() Their beaks have been found in the stomach contents of plesiosaurs (Sato and Tanabe 1998), their shells are sometimes encrusted by other inverterbates (Kase et al. Ammonites were widely distributed and have been found globally in marine deposits.Īmmonite fossils tell us a lot about ecosystems and other animals that inhabited the same environment. It’s difficult to estimate the number of described species of ammonites and few sources even attempt to do so.Īs fossils, ammonites are found in Jurassic and Cretaceous rocks and found in such abundance with rapid evolution of forms that make them useful in biostratigraphy a branch of stratigraphy that uses fossil organisms to date, correlate and interpret the geological record. Ammonitida, is the order most commonly used synonymously with ammonites. Scientific naming conventions are such that technically, ammonites are ammonoidean, ammonitidan, and sometimes strictly ammonitinan cephalopods. ![]() Taxonomically, ammonites are just one group of ammonoids, a group which includes other shelled cephalopods which first appear in the Devonian period 410 million years ago. Early 20th Century reconstructions showing very nautilus-like fleshy hoods, tentacle mass and colouration Photograph: Ammonoid by Heinrich Harder ![]()
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