What Are The Other Animals Other Than Mammals

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sea turtle (reptile). Green turtle (Chelonia mydas) (C. mydas) off the Hawaii Islands, Pacific Islands. Green sea turtle, chelonian. Homepage blog 2011, science and technology, animal — © iStockphoto/Thinkstock

How many of y'all retrieve the Brady Bunch episode in which Peter was studying for a biology test? He asked Marcia for help, and she taught him the mnemonic: "A vertebrate has a back that'due south straight." Well, not all vertebrates take direct backs, but all have backbones, or vertebral columns, that aid support their bodies.

Although the vertebral column is peradventure the most obvious feature in vertebrates, it was not present in the first ones, which probably had only a notochord (flexible rodlike structure which plays a part in the development of the nervous system). The vertebrate has a distinct head, with a differentiated brain and three pairs of sense organs (nasal, optic, and otic [hearing]). The body is divided into trunk and tail regions.

Several groups of vertebrates inhabit planet Earth. Let's take a tour of the five chief vertebrate groups alive today: the fishes, amphibians, reptiles, birds, and mammals.

Fishes

whale shark
A whale shark (Rhincodon typus) and a snorkeler off the coast of Australia.
© Comstock Images/Jupiterimages

The first fishes are thought to accept emerged some 518 million years ago during the Cambrian Period of Earth's history. Today, there more than thirty,000 species of fishes found in the fresh and table salt waters of the earth. Living species range from the primitive, jawless lampreys and hagfishes through the cartilaginous sharks, skates, and rays to the abundant and diverse bony fishes.

Fishes range in adult length from less than 10 mm (0.4 inch) to more 20 meters (60 anxiety) and in weight from about 1.5 grams (less than 0.06 ounce) to many thousands of kilograms. Some alive in shallow thermal springs at temperatures slightly higher up 42 °C (100 °F), others in cold Arctic seas a few degrees beneath 0 °C (32 °F) or in common cold deep waters more than 4,000 meters (13,100 feet) beneath the ocean surface.

Fish reproduction methods vary, merely most fishes lay a big number of small eggs that are fertilized and scattered outside of the body. The eggs of pelagic (open body of water) fishes ordinarily remain suspended in the open water, while many shore and freshwater fishes lay eggs on the bottom or among plants. The mortality of the immature and especially of the eggs is very high, and frequently only a few individuals grow to maturity out of hundreds, thousands, and in some cases millions of eggs laid.
Amphibians

red salamander (Pseudotriton ruber)
Red salamanders (Pseudotriton ruber) are establish in the eastern United States.
© Liz Weber/Shutterstock.com

Amphibians evolved from fully aquatic tetrapods—(which were substantially "limbed fish") who descended from lobe-finned fish—sometime betwixt the Early on Devonian Menstruum (which began 419 million years agone) to the Early Pennsylvanian Subperiod (which began 323 million years agone). The name amphibian, derived from the Greek amphibious meaning "living a double life," reflects this dual life strategy—though some species are permanent land dwellers, while other species have a completely aquatic style of existence.

At that place are three living groups of amphibians (caecilians, salamanders, and anurans [frogs and toads]) that, collectively, make upwardly more than than 7,300 amphibian species. One similar tendency amidst amphibians has been the evolution of direct evolution, in which the aquatic egg and free-swimming larval stages are eliminated. Evolution occurs fully within the egg capsule, and juveniles hatch equally miniatures of the developed torso form. Most species of lungless salamanders (family Plethodontidae), the largest salamander family, some caecilians, and many species of anurans have direct development. In addition, numerous caecilians and a few species of anurans and salamanders requite birth to live young.

Frogs and toads display a wide variety of life histories. Some deposit eggs on vegetation above streams or ponds; upon hatching, the tadpoles drop into the water where they continue to develop throughout their larval stage. Some species create foam nests for their eggs in aquatic (watery), terrestrial (land-based), or arboreal (tree-based) habitats; after hatching, tadpoles ordinarily develop in water. Other species eolith their eggs on state and transport them to water, while marsupial frogs are so called because they deport their eggs in a pouch on their backs. A few species lack a pouch and the tadpoles are exposed on the back; in some species, the female deposits her tadpoles in a pond equally shortly as they emerge from eggs.
Reptiles

male flying lizardPremaphotos/Nature Picture Library

Reptiles are air-animate vertebrates. They take internal fertilization, amniotic evolution (in which the embryo develops inside a set of protective extra-embryonic membranes—the amnion, chorion, and allantois), and epidermal scales covering role or all of their body. The major groups of living reptiles—the turtles, tuataras, lizards and snakes, and crocodiles business relationship for over 8,700 species.
Reptiles evolved from amphibians during the first part of the Pennsylvanian subperiod (323 meg to 299 million years ago) and retained many amphibian structural characteristics. While most reptiles feed on other organisms, a few are herbivorous (e.g., tortoises). As cold-blooded animals, reptiles tend to be limited to temperate and tropical areas, but, where they occur, they are relatively mutual; however, they are not as big or conspicuous as birds and mammals. Most reptiles are terrestrial, but a few are aquatic. They move about by creeping or swimming in a fashion similar to amphibians. Some reptiles, however, tin can lift the trunk from the ground and run rapidly either in a quadrupedal or bipedal fashion. Reptiles lay relatively large, shelled eggs. In a few instances, the eggs and young are cared for past the female; in others, the young are built-in live.
Birds

European white pelican
European white pelicans (Pelecanus onocrotalus) in flying.
© Digital Vision/Getty Images

Birds make upwards any of the 9,600 living species unique in having feathers, the major characteristic that distinguishes them from all other animals. They are warm-blooded vertebrates more related to reptiles than to mammals. They have a four-chambered heart (every bit do mammals), forelimbs modified into wings (a trait shared with bats), a difficult-shelled egg, and keen vision. Their sense of smell is non highly developed, and their auditory range is limited.

Although most are capable of flight, others are sedentary, and some are flightless. In a manner similar to their relatively close relatives the reptiles, birds lay shelled eggs. The immature are usually cared for in a nest until they are capable of flight and self-feeding, but some birds hatch in a well-adult state that allows them to brainstorm feeding immediately or fifty-fifty take flight. (Nesting activities like to those of some birds are seen in the crocodilians.)

The origin of birds, feathers, and avian flight have long been hotly debated; the evolution of birds from reptilian ancestors is universally accepted, still. The diversity of theropod dinosaurs (a diverse grouping of carnivorous "lizard-hipped" dinosaurs), some with feathers, has profoundly expanded our perspective of the development and early diversification of birds. While information technology is known that the critical catamenia in avian evolution and flight took place during the Early Cretaceous (145.v million to 99.half dozen 1000000 years agone), there is prove that feathers on theropods emerged much earlier, perhaps during the Triassic and Jurassic Periods (some 252 million to 145 million years ago).
Mammals

Okapi (Okapia johnstoni).
© IMPALASTOCK/iStock/Getty Images Plus

There are approximately v,000 species of mammals living today. Mammals differ from other vertebrate animals in that their young are nourished with milk from special mammary glands of the mother. Mammals are distinguished by several other unique features. Pilus is a typical mammalian feature, although in many whales it has disappeared except in the fetal phase. The mammalian lower jaw is hinged directly to the skull, instead of through a split bone (the quadrate) equally in all other vertebrates. A chain of three tiny bones transmits sound waves across the middle ear. A muscular diaphragm separates the heart and the lungs from the intestinal crenel. Mature carmine claret cells (erythrocytes) in all mammals lack a nucleus; all other vertebrates have nucleated scarlet blood cells. The oldest known animals classified equally mammals evolved about the boundary of the Triassic and Jurassic Periods, some 200 million years ago.

This group of vertebrates ranges in size from tiny shrews or modest bats weighing only a few grams to the largest known animals, the whales. Most mammals are terrestrial, feeding on both beast and vegetable affair, but a few are partially aquatic or entirely so, as in the instance of the whales or porpoises. Mammals motion about in a great variety of ways: burrowing, bipedal or tetrapedal (four-legged) running, flight, or swimming. Reproduction normally involves the immature developing inside the uterus, where nutritive materials are made available through an allantoic placenta or, in a few cases, a yolk sac. In placental mammals, young have a longer developmental menses within the uterus. In marsupials, the relatively undeveloped young are carried in a pouch, where they attach themselves to their female parent's nipple until they go fully adult. Monotreme mammals (that is, the platypus and echidna) differ from other mammals in that they lay eggs which hatch.