Endangered Species > Definition

What is the definition of an endangered species?WWF doesn't determine which species are considered endangered.

The IUCN (the World Conservation Union) is the organization that WWF and other conservation groups, government agencies, scientists and academics look to for that information. IUCN brings together the world's leading scientists, including those from WWF, to assess the conservation status of species, subspecies, varieties and subpopulations on a global scale, highlighting species threatened with extinction and promoting their conservation.

IUCN maintains a complete list of all the species it considers critically endangered, endangered or vulnerable: It's called the Red List of Threatened Species and can be found at http://www.redlist.org/.

From: WWF

Animal right

Animal rights, also known as animal liberation, is the idea that the interests of non-human animals—for example, avoiding suffering—should have the same consideration as the interests of human beings. Animal rights advocates argue that animals should not be regarded as property, or treated as resources for human purposes, but should instead be regarded as legal persons and members of a moral community.Extending personhood to animals is supported by legal scholars such as Alan Dershowitz and Laurence Tribe of Harvard Law School,.

The Seattle-based Great Ape Project is campaigning for the United Nations to adopt a Declaration on Great Apes, which would see gorillas, orangutans, chimpanzees and bonobos included in a "community of equals" with human beings, extending to them the protection of three basic interests: the right to life, the protection of individual liberty, and the prohibition of torture.

This is seen by an increasing number of animal rights lawyers as a first step toward granting rights to other animals. Critics of the concept of animal rights argue that animals do not have the capacity to enter into a social contract or make moral choices, and therefore cannot be regarded as possessors of moral rights. The philosopher Roger Scruton argues that only human beings have duties and that "[t]he corollary is inescapable: we alone have rights."

Critics holding this position argue that there is nothing inherently wrong with using animals for food, as entertainment, and in research, though human beings may nevertheless have an obligation to ensure they do not suffer unnecessarily. This position is generally called the animal welfare position, and it is held by some of the oldest of the animal protection agencies., also known as animal liberation, is the idea that the interests of non-human animals—for example, avoiding suffering—should have the same consideration as the interests of human beings.

From: Wikipedia

What Is a Mammal?

Humans are mammals. The word mammal comes from the Latin mamma, meaning breast, because female mammals produce milk to nurse their babies.

Nearly all mammals give birth to live young, and all are warm-blooded, maintaining a near-constant body temperature regardless of environmental conditions.

They are vertebrates and use lungs to breathe air and are the only animals that grow hair. Mammals probably appeared on Earth some 200 million years ago.

From: National Geographic

What Is a Prehistoric Animal?

Prehistoric animals are all organisms that walked—or swam, crawled, slithered, or flew—on Earth more than 5,500 years ago, before humans started recording history. The earliest known remains date to the Cambrian era, about 600 million years ago, although simple-celled organisms have been around much longer.

Crustaceans, flying reptiles, dinosaurs, woolly mammoths, and saber-toothed tigers are just a few of the hundreds of millions of prehistoric animals that once lived on Earth. Paleontologists know about these animals by studying fossils, animal remains that have been preserved in rock.

Tusoteuthis was a giant squid nearly equal in size to those that ply the oceans today—with their tentacles stretched out, the ancient cephalopods may have measured 25 to 35 feet (8 to 11 meters) long. Like the modern giant squid, Tusoteuthis lacked an outer shell and is known only from discoveries of the rigid support structure in its body called a pen or gladius. The pen was akin to a backbone but made of delicate shell-like material called chitin.

The pen supported a fleshy body with large eyes, a sharp beak, and presumably ten arms lined with suckers that made Tusoteuthis a formidable predator in the Late Cretaceous seas. Smaller cephalopods and fish were likely dietary staples, though small marine reptiles that visited the ocean depths may have fallen prey as well.

Tusoteuthis moved via jet propulsion—it expelled water through a siphon on the lower part of its body. Squirts of dark inky fluid sometimes helped the squid blind and confuse predators like the mosasaur Tylosaurus and a barracuda-like fish called Cimolichthys long enough for escape.

Fast Facts

Type: Invertebrate
Diet: Carnivore
Size: Length, 20 ft (6 m)
Did you know? A partial fossil of the predatory fish Cimolichthys contains a nearly complete backbone-like Tusoteuthis pen.
Protection status: Extinct
Size relative to a bus:

Xiphactinus was one of the largest bony fish of the Late Cretaceous and is considered one of the fiercest creatures in the sea.

A powerful tail and winglike pectoral fins shot the 17-foot-long (5-meter-long) monster through the surface waters of the ocean. Unlucky fish and unsuspecting seabirds were snared inside Xiphactinus's upturned jaw, which was lined with giant, fanglike teeth, giving it an expression akin to that of a bulldog.

A 13-foot-long (4-meter-long) Xiphactinus could open its jaw wide enough to swallow six-foot-long (two-meter-long) fish whole, but it itself was occasionally prey to the shark Cretoxyrhina.Xiphactinus trolled an ancient ocean called the Western Interior Seaway, which covered much of central North America during the Cretaceous. Though long extinct, if alive today the bony fish would look like a giant, fanged tarpon.

Fast Facts

Type: Fish
Diet: Carnivore
Size: Length, Up to 17 ft (5 m)
Did you know? A Xiphactinus on display at a museum in Kansas has a complete, well-preserved fish inside it. Scientists believe the struggling prey ruptured an organ of its captor as it was swallowed, killing the larger fish.
Protection status: Extinct

From: National Geagraphic