More than 1 million species are at risk of extinction, and several others have already disappeared as scientists continue to warn the world about the situation.

Some of those that recently became extinct include species like the Pinta giant tortoise, ivory-billed woodpecker, Spix's macaw, Western Black rhino, Tasmanian tigers and Bramble Cay melomys.

Lonesome George, a Pinta giant tortoise, died of unknown causes in 2012. He was the last of his kind and was among the species that helped Charles Darwin formulate his theory of evolution in the 19th century, writes DW.

Lonesome George
Lonesome George, thought to be the last giant Galapagos tortoise, died in 2012. (Reuters)

Western Black rhinos were declared extinct in 2011. The species was once found across the savannas of sub-Saharan Africa, but the number of rhinos declined largely due to poaching and hunting.

Western Black rhinos
Photo of a western Black rhinos by Gary M. Stolz, USFWS on Pixnio

At the beginning of the 20th century, there were half a million rhinos across Africa and Asia, but now there are only around 27,000. However, population numbers are slowly increasing again, per WWF.

Species like the Yangtze River dolphins have not been spotted in more than 20 years. Climate change and rapid industrialisation have proven to be deadly for many such creatures who could not adapt to the changes.

The most famous species that became extinct centuries ago was the dodo bird. The bird made an appearance in Lewis Carroll's book "Alice's Adventures in Wonderland." It was last seen in 1662 after having been hunted to extinction.

A skeleton of a Mauritius Dodo bird which was found by E. Thirioux, a barber.
A skeleton of a Mauritius Dodo bird which was found by E. Thirioux, a barber Reuters

Scientists have no idea how many species of plants and animals have gone extinct because no one knows the exact number of species on the planet.

According to International Union for Conservation of Nature (IUCN) Red List estimates, a quarter of mammals are also at risk of extinction. The latest study said that the crisis is even worse than we thought.

The study by researchers from the Norwegian University of Science and Technology revealed that more than half of species—about which there is not much data available—face the threat of extinction.

Wildlife experts suggest reducing the usage of fossil fuels, eating less meat, avoiding products made of animal body parts if we wish to save these creatures.

Tasmanian tigers
Tasmanian tigers went extinct in 1936. Smithsonian Institutional Archives, 1904