Cephalopods Report

Cephalopoda Taxonomic Classification: Kingdom Animalia Phylum phylum Mollusca Class Cephalopoda (literally, detail foot) Extant Sub gradationes Coleoidea (octopuses, squid, and cuttlefishes) & Nautiloidea (nautilus) nonexistent Subclasses Ammonoidea (ammonites) & Belemnoidea (belemnites) Species Roughly 800 antithetic extant species pee been named. An estimated 11,000 deceased 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 dissent from another(prenominal) mollusks in many shipway: the dead body regulate of cephalopods is characterized by the fore-shortening of the anterior-posterior axis and elongation of the dorsal- dorsoventral axis. there has also been a pitch in the penchant of the body so that the ventral region is stra ight off anterior and the intuitive mass is now the functional posterior dying of the animal. This transform 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 sea captain foot into a series of en swelledd prehensile tentacles or arms at the anterior end which now touch 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 hav e been named. The Ammonoidea arose during ! Devonian time and grew to large and diverse numbers game 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: OrderCustomPaper.com

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