The six basic animal groups include

The six basic animal groups include amphibians, birds, fish, invertebrates, mammals, and reptiles. Although there are many other groups of animals, and the way scientists classify and categorize species changes frequently, in this article I'll keep it simple by focusing on just six basic groups.
If you're just starting to learn about animals and wildlife, it would be an overwhelming task to try and memorize species, one by one. Instead, an understanding of the main groups of animals provides a good foundation for further learning. Once you have a understanding of the six groups listed below, you'll be on your way to grasping the basic characteristics of virtually every animal on the planet.
Invertebrates were the first animals to evolve, and they did so from single-celled microorganisms. Fossil evidence of early invertebrates dates back to the late Precambrian, 600 million years ago. Since that time, invertebrates have diversified into countless forms. A staggering 97 percent of all species alive today are invertebrates. As a group, invertebrates are united more by what they lack (a backbone) than by shared characteristics.Invertebrates include animal groups such as sponges, cnidarians, flatworms, molluscs, arthropods, segmented worms, and echinoderms as well as many other lesser-known groups of animals. The most notable characteristic of invertebrates is that they have no backbone. Additionally, members of this group are ectothermic. The high diversity of the group means that few other key characteristics can be ascribed to all invertebrates. Instead, it is more valuable to understand the characteristics that unite each of the invertebrate subgroups.
Fishes were some of the the first vertebrates to evolve from invertebrate ancestors. The earliest known fishes were the ostracoderms, a now-extinct group of jawless fishes that appeared in the Cambrian Period, about 510 million years ago. Other early fish include the conodonts and the agnanthans (the hagfish and the lamprey). Fishes later evolved jaws and diversified into a number of lineages including cartilaginous fishes, ray-finned fishes, and lobe-finned fishes. There are an estimated 25,000 species of fishes alive today.Fishes include the bony fishes, cartilaginous fishes, lampreys, and hagfishes. Fishes are vertebrates—which means that like birds, amphibians, mammals, and reptiles, they have a backbone. Fishes were the first vertebrates to evolve jaws and they breath using gills. Fish have no limbs and most are ectothermic.
Amphibians were the first vertebrates to transition from living in water to living on dry land (or at least moist land). Despite their early colonization of terrestrial habitats, most lineages of amphibians have never fully abandonned their ties with aquatic habitats. The first amphibians evolved about 370 million years ago during the Devonian Period from ancestors that were lobe-finned fishes. Today, there are between 5,000 and 6,000 species of amphibians.Amphibians includes newts, salamanders, toads, frogs, and caecilians. Amphibian species are in decline around the world due to a variety of threats including of invasive species, habitat destruction, disease, climate change and toxins. Amphibians—like fishes, mammals, birds, and reptiles—are vertebrates. They have four legs, a characteristic that means they are also tetrapods. Amphibians are ectothermic and their life cycle includes an aquatic larval stage.
Reptiles are cold-blooded vertebrates that diverged from ancestral amphibians about 340 million years ago during the Carboniferous Period. Early reptiles included organisms such as Hylonomus, Petrolacosaurus, Archaeothyris and Paleothyris. The oldest evidence of reptiles is a set of 315-million-year-old fossilized footprints found in Nova Scotia. The ancient footprints had five fingers and scales, which confirms they were made by early reptiles. There are about 8,000 species of reptiles alive today.Reptiles include turtles, squamates, crocodiles, and tuatara. Two characteristics distinguish early reptiles from amphibians: scales and the ability to lay hard-shelled amniotic eggs. Reptiles are also tetrapods (four-legged vertebrates), most of which are ectotherms.
Mammals are vertebrates that evolved from therapsid reptiles during the Jurassic Period, about 200 million years ago. The first mammals, known as morganucodontids, were nocturnal insect eaters that resembled modern-day shrews. For the better part of 130 million years, mammals remained small and lived in a world dominated by the dinosaurs. But around 65 million years ago, a drastic shift in climate caused the extinction of more than two-thirds of the animal species on the planet, including the dinosaurs. Today, mammals are remarkably varied, with some 5,400 species occupying every continent on the globe.Some of the better-known mammal groups include carnivores, rodents, elephants, marsupials, rabbits, bats, primates, seals, anteaters, cetaceans, odd-toed ungulates and even-toed ungulates. Mammals possess a number of characteristics that are uniquely theirs including hair, mammary glands, and a lower jaw that consists of a single bone. Like amphibians, birds, and reptiles, mammals are also tetrapod vertebrates. They maintain their own internal body temperature (endothermic), have a diaphram, a four-chambered heart and specialized middle ear bones.
Birds evolved from reptiles during the Mesozoic Era about 150 million years ago. The first birds are thought to have evolved from a group of small, carnivorous dinosaurs called theropods. The earliest known bird is Archaeopteryx, an ancient bird that was discovered when its fossil remains were unearthed in the early 1860s. Today, more than 9,000 species of birds have colonized virtually every terrestrial habitat on the planet.Some of the better-known bird groups include birds of prey, flamingos, perching birds, gamebirds, pigeons and doves, hummingbirds, owls, pelicans, and penguins. Birds have a number of characteristics that sets them apart from other vertebrates such as their feathers, bills, and furculas. Birds, best known for their ability to fly, remain unmatched in their command of the skies.

Results (English) 2:

The six basic animal groups include amphibians, birds, fish, invertebrates, mammals, and reptiles. Although there are many groups of animals Other, and the Way scientists classify and categorize species changes Frequently, I'll Keep it Simple in this Article by just focusing on Basic Six groups.
If You're Starting to Learn About just animals and Wildlife,. it would be an overwhelming task to try and memorize species, one by one. Instead, an understanding of the main groups of animals provides a good foundation for further learning. You have a once understanding of the Six groups listed Below, You'll be on your Way to Grasping the Basic characteristics of virtually every Animal on the Planet.
Invertebrates were the First to Evolve animals, and they did so from single-celled microorganisms. Fossil evidence of early invertebrates dates back to the late Precambrian, 600 million years ago. Since that time, invertebrates have diversified into countless forms. A staggering 97 percent of all species alive today are invertebrates. As a group, invertebrates are united more by what they lack (a backbone) than by shared characteristics.Invertebrates include animal groups such as sponges, cnidarians, flatworms, molluscs, arthropods, segmented worms, and echinoderms as well as many other lesser-known. groups of animals. The most notable characteristic of invertebrates is that they have no backbone. Additionally, members of this group are ectothermic. The high diversity of the group means that few other key characteristics can be ascribed to all invertebrates. Instead, it is more Valuable to Understand the characteristics that each of the invertebrate Unite subgroups.
Some of the Fishes were the First vertebrates to Evolve from invertebrate Ancestors. The earliest known fishes were the ostracoderms, a now-extinct group of jawless fishes that appeared in the Cambrian Period, about 510 million years ago. Other early fish include the conodonts and the agnanthans (the hagfish and the lamprey). Fishes later evolved jaws and diversified into a number of lineages including cartilaginous fishes, ray-finned fishes, and lobe-finned fishes. There are an estimated 25,000 species of fishes alive today.Fishes include the bony fishes, cartilaginous fishes, lampreys, and hagfishes. Fishes are vertebrates-which means that like birds, amphibians, mammals, and reptiles, they have a backbone. Fishes were the first vertebrates to evolve jaws and they breath using gills. Fish have no limbs and Most are ectothermic.
Amphibians were the First vertebrates to transition from Living in Water to Living on Dry Land (or at Least moist Land). Despite their early colonization of terrestrial habitats, most lineages of amphibians have never fully abandonned their ties with aquatic habitats. The first amphibians evolved about 370 million years ago during the Devonian Period from ancestors that were lobe-finned fishes. Today, there are between 5,000 and 6,000 species of amphibians.Amphibians includes newts, salamanders, toads, frogs, and caecilians. Amphibian species are in decline around the world due to a variety of threats including of invasive species, habitat destruction, disease, climate change and toxins. Amphibians-like fishes, mammals, birds, and reptiles-are vertebrates. They have four legs, a characteristic that means they are also tetrapods. Amphibians are ectothermic and their Life Cycle includes an Aquatic larval Stage.
Reptiles are cold-Blooded that diverged from vertebrates 340 million years ago About Ancestral amphibians during the Carboniferous Period. Early reptiles included organisms such as Hylonomus, Petrolacosaurus, Archaeothyris and Paleothyris. The oldest evidence of reptiles is a set of 315-million-year-old fossilized footprints found in Nova Scotia. The ancient footprints had five fingers and scales, which confirms they were made ​​by early reptiles. There are about 8,000 species of reptiles alive today.Reptiles include turtles, squamates, crocodiles, and tuatara. Two characteristics distinguish early reptiles from amphibians: scales and the ability to lay hard-shelled amniotic eggs. Reptiles are also tetrapods (Four-legged vertebrates), Most of which are ectotherms.
Mammals are vertebrates that during the Jurassic Period Evolved from therapsid Reptiles, About 200 million years ago. The first mammals, known as morganucodontids, were nocturnal insect eaters that resembled modern-day shrews. For the better part of 130 million years, mammals remained small and lived in a world dominated by the dinosaurs. But around 65 million years ago, a drastic shift in climate caused the extinction of more than two-thirds of the animal species on the planet, including the dinosaurs. Today, mammals are remarkably varied, with some 5,400 species occupying every continent on the globe.Some of the better-known mammal groups include carnivores, rodents, elephants, marsupials, rabbits, bats, primates, seals, anteaters, cetaceans, odd-toed. ungulates and even-toed ungulates. Mammals possess a number of characteristics that are uniquely theirs including hair, mammary glands, and a lower jaw that consists of a single bone. Like amphibians, birds, and reptiles, mammals are also tetrapod vertebrates. They maintain their own internal Body Temperature (Endothermic), have a diaphram, a Four-chambered Heart and Bones specialized MIDDLE EAR.
Birds Evolved during the Mesozoic Era from Reptiles About 150 million years ago. The first birds are thought to have evolved from a group of small, carnivorous dinosaurs called theropods. The earliest known bird is Archaeopteryx, an ancient bird that was discovered when its fossil remains were unearthed in the early 1860s. Today, more than 9,000 species of birds have colonized virtually every terrestrial habitat on the planet.Some of the better-known bird groups include birds of prey, flamingos, perching birds, gamebirds, pigeons and doves, hummingbirds, owls, pelicans, and penguins. . Birds have a number of characteristics that sets them apart from other vertebrates such as their feathers, bills, and furculas. Birds, best known for their ability to fly, remain unmatched in their command of the skies.

Results (English) 3:

The six basic animal groups include amphibians birds fish,,,,, invertebrates mammals and reptiles. Although there are many. Other groups, of animals and the way scientists classify and categorize species changes frequently in this, article I LL. ' Keep it simple by focusing on just six basic groups.
If you 're just starting to learn about animals, and wildlifeIt would be an overwhelming task to try and, memorize species one by one. Instead an understanding, of the main groups. Of animals provides a good foundation for further learning. Once you have a understanding of the six groups, listed below. You 'll be on your way to grasping the basic characteristics of virtually every animal on the planet.
Invertebrates were. The first animals, to evolveAnd they did so from single-celled microorganisms. Fossil evidence of early invertebrates dates back to the late Precambrian 600 million,, Years ago. Since that time invertebrates have, diversified into countless forms. A staggering 97 percent of all species. Alive today are invertebrates. As a group invertebrates are, United more by what they lack (a backbone) than by shared characteristics.Invertebrates include animal groups such as sponges cnidarians flatworms molluscs,,,,,,, arthropods segmented worms and Echinoderms as well as many other lesser-known groups of animals. The most notable characteristic of invertebrates is that. They have no backbone. Additionally members of, this group are ectothermic.The high diversity of the group means that few other key characteristics can be ascribed to all invertebrates, Instead,. It is more valuable to understand the characteristics that unite each of the invertebrate subgroups.
Fishes were some of. The the first vertebrates to evolve from invertebrate ancestors. The earliest known fishes were, the ostracodermsA now-extinct group of jawless fishes that appeared in the, Cambrian Period about 510 million years ago. Other early fish. Include the conodonts and the agnanthans (the hagfish and the lamprey). Fishes later evolved jaws and diversified into a. Number of lineages including cartilaginous fishes ray-finned fishes, and lobe-finned, fishes. There are an estimated 25 000 species,, Of fishes alive today.Fishes include the bony fishes cartilaginous fishes,,, lampreys and hagfishes. Fishes are vertebrates - which means that. Like birds amphibians mammals,,,, and reptiles they have a backbone. Fishes were the first vertebrates to evolve jaws and. They breath using gills. Fish have no limbs and most are ectothermic.
.Amphibians were the first vertebrates to transition from living in water to living on dry land (or at least moist land).? Despite their early colonization of terrestrial habitats most lineages, of amphibians have never fully abandonned their. Ties with aquatic habitats. The first amphibians evolved about 370 million years ago during the Devonian Period from ancestors. That were lobe-finned fishes.Today there are, between 5 000 6 000, and, species of amphibians.Amphibians includes newts salamanders toads,,,,, frogs and Caecilians. Amphibian species are in decline around the world due to a variety of threats including of, invasive species. Habitat, destruction disease climate change, and toxins. Amphibians like fishes -,,, mammals birds and reptiles - vertebrates, are. They have, four legsA characteristic that means they are also tetrapods. Amphibians are ectothermic and their life cycle includes an aquatic. Larval stage.
Reptiles are cold-blooded vertebrates that diverged from ancestral amphibians about 340 million years ago. During the Carboniferous Period. Early reptiles included organisms such as Hylonomus Petrolacosaurus Archaeothyris and,,, Paleothyris.