Chondrichthyes or cartilaginous fishes are jawed fish with paired fins, paired nostrils, scales, two-chambered hearts, and skeletons made of cartilage rather than bone.They are divided into two subclasses: Elasmobranchii (sharks, rays and skates) and Holocephali (chimaera, sometimes called ghost sharks). Every shark belongs to the classification Chondrichthyes which identifies them as cartilaginous fish, fish whose internal skeletons are comprised of flexible cartilage rather than bone. Chondrichthyan - Chondrichthyan - Form and function: The elasmobranchs are fishlike vertebrates that differ from bony fishes in many respects. Class 2. They are cartilaginous fish along with skates, rays and chimeras. There are over 350 species of sharks known worldwide. Examples – Climatius, Dinichthys. Sharks are one of the earliest known jawed fishes. Sharks are one of the earliest known jawed fishes. Class 1. Elasmobranchii (/ ɪ ˌ l æ z m ə ˈ b r æ ŋ k i aɪ /) is a subclass of Chondrichthyes or cartilaginous fish, including the sharks (superorder Selachii) and the rays, skates, and sawfish (superorder Batoidea). The class includes a diverse group of fishes including sharks, rays, skates and chimaeras. Chondrichthyes is a class of jawed fishes having a cartilaginous skeleton. Phylum - Chordata - Division In Vertebrata: Cyclostomata, Pisces, Chondrichthyes, Osteichthyes, Amphibia, Amphibia, Reptilia, Aves, Mammalia. Source | Credits | Picture Credits: NCERT General Science Phylum - Chordata Animals belonging to phylum Chordata are fundamentally characterised by the presence of a notochord, a dorsal hollow nerve cord and paired pharyngeal gill … The tail has two lobes, the upper lobe is elongated and vertebrae extends into it and a shorter lower lobe, … Subclass Elasmobranchii (sharks, rays and skates) There are five to seven fully developed gill clefts, opening separately to the exterior. Like other fish skeletons you’ve seen, you’d expect a rib cage and hard bones to reveal themselves as the animal decayed. Cartilaginous endoskeleton. Mr. Christian's class at KOHS Chondrichthyes study guide by KaylaToi includes 47 questions covering vocabulary, terms and more. Placoderms. The sharks, rays, and chimaeras make up the second group of fish, the Class Chondrichthyes. 3. They have no bony skeleton. Scallops of the placoid type, exclusive of this group – are scales similar to small teeth, formed by dentin and a type of enamel (enamel is a highly mineralized tissue, very hard, of epidermal origin, as opposed to dentin and bone, of origin mesodermic), immersed in the body of the animal (the tip of the scale breaks the skin), giving a rough, “sandpaper” texture. Class Chondrichthyes. Sharks are classified as follows: Kingdom Animalia Phylum Chordata SubPhylum Vertebrata Class Chondrichthyes (cartilaginous fish) Subclass Plagiostomi (sharks and rays: upper jaw hung from skulls and different kind of blood) Superorder Selachimorpha (sharks: free upper eyelids, gill openings on the head, and pectoral fins separate from … Yet sharks are unique. Sharks belong to the superorder Selachimorpha in the subclass Elasmobranchii in the class Chondrichthyes.The Elasmobranchii also include rays and skates; the Chondrichthyes also include Chimaeras.It was thought that the sharks form a polyphyletic group: some sharks are more closely related to rays than they are to some other sharks, but current molecular studies support monophyly of … The skeleton is composed of cartilage and, although often calcified (especially in the vertebrae), lacks true bone (except in the roots of teeth). Mostly marine. Taxonomy. A full-sized functional gill-arch precedes hyoid arch. 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