Bird with unusually long toes found fossilized in amber

Meet the ancient bird that had toes longer than its lower legs. Researchers have discovered a bird foot from 99 million years ago preserved in amber that had a hyper-elongated third toe. The study, published in the journal ...

2 rare Barbary lion cubs born in Czech zoo

Two Barbary lion cubs have been born in a Czech zoo, a welcome addition to a small surviving population of a rare lion subspecies that has been extinct in the wild.

Analysis of the parietal anatomy of Old World monkeys

The Paleoneurology group at the CENIEH, coordinated by Emiliano Bruner, has just published a paper in the journal American Journal of Primatology on the variations and differences in the parietal lobes of different species ...

When the dinosaurs died, lichens thrived

When an asteroid smacked into the Earth 66 million years ago, it triggered mass extinctions all over the planet. The most famous victims were the dinosaurs, but early birds, insects, and other life forms took a hit too. The ...

Some extinct crocs were vegetarians

Based on careful study of fossilized teeth, scientists Keegan Melstom and Randall Irmis at the Natural History Museum of Utah at the University of Utah have found that multiple ancient groups of crocodyliforms—the group ...

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Extinction

In biology and ecology, extinction is the end of a species or group of taxa. The moment of extinction is generally considered to be the death of the last individual of that species (although the capacity to breed and recover may have been lost before this point). Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "re-appears" (typically in the fossil record) after a period of apparent absence.

Through evolution, new species arise through the process of speciation—where new varieties of organisms arise and thrive when they are able to find and exploit an ecological niche—and species become extinct when they are no longer able to survive in changing conditions or against superior competition. A typical species becomes extinct within 10 million years of its first appearance, although some species, called living fossils, survive virtually unchanged for hundreds of millions of years. Extinction, though, is usually a natural phenomenon; it is estimated that 99.9% of all species that have ever lived are now extinct.

Prior to the dispersion of humans across the earth, extinction generally occurred at a continuous low rate, mass extinctions being relatively rare events. Starting approximately 100,000 years ago, and coinciding with an increase in the numbers and range of humans, species extinctions have increased to a rate unprecedented since the Cretaceous–Tertiary extinction event. This is known as the Holocene extinction event and is at least the sixth such extinction event. Some experts have estimated that up to half of presently existing species may become extinct by 2100.

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