This lifeform is found in northern Eurasia. This lifeform is found north of the Mason Dixon line in North America.
Rock Ptarmigan (Lagopus mutus) is found circumpolar in the arctic regions. It is very similar in coloration to the Willow Ptarmigan, but the smaller size, thirteen inches, helps separate it from its larger relative.
Grouse Family (Family Tetraonidae) contains 18 species of birds that are found in both North America and Eurasia. The downward curve of the short helps separate the various Grouse from the other families in the Galliformes order.
Fowl group (Galliformes order) contains the various chickens and turkey-like birds of the world. There are about 240 different species of fowl known. Many of the wild species are endangered. Several species such as the domesticated chicken and turkey are main food sources in the world. Most fowl are grain eaters and spend a good portion of their life searching for food on the ground. Select species have been domesticated for their beauty and/or edibility, others are considered good game birds.
Aves contains about 8,650 different species of living birds known to science. Each year about one new species is discovered in some remote rain forest or remote island. In addition, scientists have been raising many subspecies to full species status which may raise the species count to 10,000.
However, each year about one species goes extinct. The rate of extinction is increasing, and the rate of new discovery is decreasing, so that the number of bird species will soon begin to decline rapidly. Although different taxonomists would organize the birds differently, there are approximately twenty-seven orders of birds. These orders are broken down into about one hundred and fifty-five different families.
Recent research of the genetic structure of some of the shore birds and owls would indicate that the present organization of orders and families should have some modification.
The birds are a worldwide group of animals that are characterized by having the front limbs modified into wings that are used for flying. Perhaps the most unique feature of the birds is the feathers. These feathers are made up of a central support called a quill and a series of small filaments that are hooked together as barbs.
For many years it was believed that Archaeopteryx discovered in Bavaria was the oldest bird from about 150 million years ago. However, in l986, Sankar Chattterjee, a Texas paleontologist, reportedly discovered a bird in the genus Protoavis that lived about 225 million years ago.
Backboned Animals (Phylum Chordata) are the most advanced group of animals on earth. These animals are characterized by having a spinal cord or backbone. Most members have a clearly defined brain that controls the organism through a spinal cord. Fish, amphibians, reptiles, birds, and mammals are in this phylum.
Currently, some taxonomists believe that the fish should be divided into two groups (sharks and regular fishes) and that there are some other primitive groups in the phylum such as hagfish or lampreys.
Animal Kingdom contains numerous organisms that feed on other animals or plants. Included in the animal kingdom are the lower marine invertebrates such as sponges and corals, the jointed legged animals such as insects and spiders, and the backboned animals such as fish, amphibians, reptiles, birds, and mammals.