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The single extant species of tuatara is the only surviving member of its order, which was highly diverse during the Mesozoic era. [10] Rhynchocephalians first appeared in the fossil record during the Triassic , around 240 million years ago, [ 11 ] and reached worldwide distribution and peak diversity during the Jurassic , when they represented ...
Skeletal changes of vertebrates transitioning from water to land. Innovations conventionally associated with terrestrially first appeared in aquatic elpistostegalians such as Panderichthys rhombolepis, Elpistostege watsoni, and Tiktaalik roseae. Phylogenetic analyses distribute the features that developed along the tetrapod stem and display a ...
The African bullfrog is a voracious carnivore, eating insects and other invertebrates, small rodents, reptiles, small birds, fish, and other amphibians that can fit in their mouths. [ 5 ] [ 9 ] [ 10 ] It is also a cannibalistic species—the male African bullfrog is known for occasionally eating the tadpoles he guards, [ 11 ] and juveniles also ...
Aquatic respiration. Sea slugs respire through a gill (or ctenidium) Aquatic respiration is the process whereby an aquatic organism exchanges respiratory gases with water, obtaining oxygen from oxygen dissolved in water and excreting carbon dioxide and some other metabolic waste products into the water.
Chondrichthyes (/ kɒnˈdrɪkθiiːz /; from Ancient Greek χόνδρος (khóndros) 'cartilage' and ἰχθύς (ikhthús) 'fish') is a class of jawed fish that contains the cartilaginous fish or chondrichthyans, which all have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or bony fish, which have ...
Gill. The red gills of this common carp are visibly exposed as a result of a gill flap birth defect. A gill (/ ɡɪl / ⓘ) is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land ...
Chimaeras differ from other cartilagenous fish, having lost both the spiracle and the fifth gill slit. The remaining slits are covered by an operculum, developed from the septum of the gill arch in front of the first gill. [6] The shared trait of breathing via gills in bony fish and cartilaginous fish is a famous example of symplesiomorphy.
Obelia bidentata. Obelia longissima. Obelia is a genus of hydrozoans, a class of mainly marine and some freshwater animal species that have both polyp and medusa stages in their life cycle. Hydrozoa belongs to the phylum Cnidaria, which are aquatic (mainly marine) organisms that are relatively simple in structure with a diameter around 1mm. [1]