Mammals (class Mammalia (pron.: /mÉËmeÉªli.É/)) are a clade of warm-blooded amniotes. Among the features that distinguish them from the other amniotes, the reptiles and the birds, are hair, three middle ear bones, mammary glands in females, and a neocortex (a region of the brain). The mammalian brain regulates body temperature and the circulatory system, including the four-chambered heart. The mammals include the largest animals on the planet, the rorqual whales, as well as some of the most intelligent, such as elephants, some primates and some cetaceans. The basic body type is a four-legged land-borne animal, but some mammals are adapted for life at sea, in the air, in the trees, or on two legs. The largest group of mammals, the placentals, have a placenta which feeds the offspring during pregnancy. Mammals range in size from the 30â40 millimeter (1- to 1.5-inch) bumblebee bat to the 33-meter (108-foot) blue whale.
After the great dinosaur extinction some 65 million years ago, mammals finally had their big shot as numerous niches became free for the taking. Thus, from mouse size, some mammal species surfaced which were as large as a bus, the so called mammal megafauna, like mammoths, giant sloths or saber-tooth tigers. However, a dire trial of their [...]
A recently published study suggests that the Earth might have been visited by a giant space rock 13,000 years ago, an event which might have sparked an unusual cold period in the planet’s climate history. The Younger Dryas, also known as the Big Freeze, was a brief period of cold climatic conditions and drought which occurred [...]
Around 140 millions years ago, mammals didn’t even outsize a modern day mouse, as dinosaurs dominated Earth’s crowded surface. As the latter became extinct, a myriad of free ecosystems and niches opened up, including those once dominated by giant plant eating dinosaurs, and mammals where quick to fill these up. After compiling and analyzing a [...]
Humans, as well as most mammals, have only two sets of teeth to make with during their entire lifetime. However, a new research published in the journal Proceedings of the National Academy of Sciences, which studied the dental structure of mole rats has shown that the species is an exception to this rule. In fact, [...]
Common sense might tell you that only mammals are capable of lactating, it’s a little know fact, however, that some species of birds are also capable of making milk for their young. The common pigeon produces milk in its crop, located near the esophagus, to feed its young. Scientists have long been wondering how the [...]
A recently published study 8 years in the making reveals the uncanny ability humpback whales have of following seemingly perfect straight paths for weeks at a time. The navigational precision of humpback whales cannot be explained by known theories. Humpback whales feed during the summer near polar oceans and migrate to warm tropical oceans for [...]
The previous 5 mass extinctions wiped out more than three quarters of the world’s animals, and if things continue to move in the same way, the same thing will happen in North America, according to a University of California, Berkeley, and Pennsylvania State University analysis. Numerous scientists have warned that the direction things are moving [...]