Cephalopods Report

Cephalopoda

Taxonomic Classification:
Kingdom Animalia
Phylum Mollusca
Class Cephalopoda (literally, detail foot)
Extant Subclasses Coleoidea (octopuses, squid, and cuttlefishes) & Nautiloidea (nautilus)
Extinct Subclasses Ammonoidea (ammonites) & Belemnoidea (belemnites)
Species Roughly 800 antithetic extant species have been named. An estimated 11,000 dead taxa have been described.
As you cigaret see, cephalopods are a class within the phylum: Mollusca. The phylum Mollusca includes class Gasteropoda (gastropods, snails, and slugs), and bivalvia (bivalves, scallops, oysters, and clams), among new(prenominal)s. Cephalopods differ from another(prenominal) mollusks in many shipway: the dead body form of cephalopods is characterized by the fore-shortening of the anterior-posterior axis and elongation of the dorsal-ventral axis. there has also been a pitch in the orientation of the body so that the ventral region is now anterior and the intuitive mass is now the functional posterior dying of the animal. This change in orientation has implications for sensory function and cephalopod locomotion. The other major change from the basic molluscan plan exhibited by the cephalopods is the renewal of much of the original foot into a series of en swelledd prehensile tentacles or arms at the anterior end which now surround the head.




Cephalopods throughout the ages:
It is believed that cephalopods evolved from an ancient group of gastropods. The fogey record of cephalopods is extensive, and more than 10,000 fossil species have been named. The Ammonoidea arose during Devonian time and grew to large and diverse numbers during the Mesozoic. An ammonite had an external, coiled shell mistakable to that of Nautilus. Ammonites were very successful scientists have described 1,200 genera based on shell type from the Jurassic and Cretaceous Periods but became extinct at the end of the Mesozoic along with dinosaurs, some mammals, and other marine animals. Belemnoids, which also appeared in the...If you want to get a full essay, order it on our website: Orderessay



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