Evolution. 2

Originally i wanted to research al animals and their attributes, but after realising that field is far too big to tackle i considered Insects and obviously the field of insects is equally as large.


These are the possible groups of animals i would like to consider.

- Mammals
- Birds
- Reptiles
- Amphibians

These types of animals are all invertebrates which means they are animals with backbones, the other type of creatures on earth are invertebrates, animals without backbones, the only group in this section are 'Arthropods' or more commonly known as insects, as i have stated i feel this group is far too large for me to cover.

Considering each group and its sub groups will help me choose my final top ten catagory.


Mammals.


Eutheria - (pronounced /juːˈθɪəriə/; Greek ευθήριον, pronounced euthérion and meaning "true/good beasts") is a group of mammals consisting of placental mammals plus all extinct mammals that are more closely related to living placentals (such as humans) than to living marsupials (such as kangaroos). They are distinguished from noneutherians by various features of the feet, ankles, jaws and teeth. One of the major differences between placental and nonplacental eutherians is that placentals lack epipubic bones, which are present in all other fossil and living mammals (monotremes and marsupials).

Marsupials - are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central America, and one in North America, north of Mexico.

Monotremes - (from the Greek μονός monos "single" + τρῆμα trema "hole", referring to the cloaca) are mammals that lay eggs (Prototheria) instead of giving birth to live young like marsupials (Metatheria) and placental mammals (Eutheria). The only surviving examples of monotremes are all indigenous to Australia and New Guinea, although there is evidence that they were once more widespread. Among living mammals they include the platypus and four species of echidnas (or spiny anteaters); there is debate regarding monotreme taxonomy


Reptiles.

Crocodilia - As the name suggests, this order of reptiles includes about 23 species of crocodiles, alligators, gharials and caimans. In all, there are approximately 25 individual species of reptile within the Crocodilia order.

Squamata - This order of reptiles includes snakes and lizards. So as you might imagine, it is by far the largest order of reptiles, including more than 7,000 individual species.

Testudines - This reptile order is made up of turtles and tortoises. Under the current system of reptile classification, there are approximately 300 species of turtle and tortoise in the Testudines order of reptiles.

Sphenodontia - This is the least known and smallest order of reptiles. It is comprised of only two species of tuataras from New Zealand. The tuatara resembles a lizard, but it is equally related to both snakes and lizards. It is the last living member of this group of reptiles, which flourished around 200 million years ago toward the end of the "Dinosaur Era."

Birds.

Upon researching for birds i have found they also have a huge subgroup section, for this reason i will look into the most commonly known groups of birds.

Birds of paradise.

The birds-of-paradise are members of the family Paradisaeidae of the order Passeriformes. The majority of species in this family are found on the island of New Guinea and its satellites, with a few species occurring in the Moluccas and eastern Australia. The family has forty species in 14 genera. The members of this family are perhaps best known for the plumage of the males of most species, in particular highly elongated and elaborate feathers extending from the beak, wings or head. For the most part they are confined to dense rainforest habitat. The diet of all species is dominated by fruit and to a lesser extent arthropods. The birds-of-paradise have a variety of breeding systems, ranging from monogamy to lek-based polygamy.

Birds of prey.

Birds of prey are birds that hunt for food primarily on the wing, using their keen senses, especially vision. They are defined as birds that primarily hunt vertebrates, including other birds. Their talons and beaks tend to be relatively large, powerful and adapted for tearing and/or piercing flesh. In most cases, the females are considerably larger than the males. The term "raptor" is derived from the Latin word rapere (meaning to seize or take by force) and may refer informally to all birds of prey, or specifically to the diurnal group. Because of their predatory lifestyle, often at the top of the food chain, they face distinct conservation concerns.

Amphibians.

Newts and salamanders - diverged from other amphibians during the Permian Period (286 to 248 million years ago). Newts and salamanders are slender-bodied amphibians that have a long tail and four legs. Newts spend most of their life on land and return to water to breed. Salamanders, in contrast, spend their entire lives in water.
Newts and salamanders are classified into about ten families, some of which include mole salamanders, giant salamanders, Asiatic salamanders, lungless salamanders, sirens, and mudpuppies.

Frogs and toads - belong to the largest of the three groups of amphibians. There are more than 4,000 species of frogs and toads alive today. The earliest known frog-like ancestor is Gerobatrachus, a toothed amphibian that lived about 290 million years ago. Another early frog was Triadobatrachus, an extinct genus of amphibian that dates back 250 million years.
Modern adult frogs and toads have four legs but do not have tails. There are about 25 families of frogs including such groups as gold frogs, true toads, ghost frogs, Old World tree frogs, African tree frogs, spadefoot toads, and many others.

Caecilians - are the least-known group of amphibians. Caecilians have no limbs and only a very short tail. They have a superficial resemblance to snakes, worms, or eels but are not closely related to any of these animals.
The evolutionary history of caecilians remains obscure and few fossils of this group of amphibians have been discovered. Some scientists suggest that caecilians arose from a group of tetrapods known as the Lepospondyli.