Extinct Species – Concept, mass extinctions and examples

We explain what an extinct species is, what were the mass extinctions in history and examples of extinct and protected species.

Galapagos tortoise - Extinct species
The species are still going extinct even today.

What is an extinct species?

When we refer to an extinct species, we refer to one whose last individuals have died, that is, to a species that no longer exists, and of which only traces remain in the fossil record or in studies that humanity has made of it.

Extinction it is a common phenomenon throughout the history of our planet, Athough it does not seems. There have been various episodes of mass extinction that have reduced the quantity and diversity of life in the world, as well as other smaller ones or those of a local area, and isolated cases of species that have become extinct, giving way to others better prepared for use. of the resources.

The most famous of the cases of extinct species is that of dinosaurs: huge lizards that ruled the Earth until 65 million years ago, when they became massively extinct; probably as a consequence of drastic and rapid changes in the climate or the world temperature, which according to some theories would have been produced by the fall of a huge meteorite.

Nevertheless, species continue to become extinct even today, especially due to actions and activities of the human species such as massive environmental pollution, selective and uncontrolled hunting and logging, the introduction of alien species into carefully balanced habitats, etc.

Mass extinctions in history

Extinct species - dinosaurs
The Cretaceous-Paleogene extinction wiped out the dinosaurs, among other species.

Throughout the geological history of the planet, life appeared, proliferated and diversified, becoming more complex, but also perished and became extinct en masse. The main mass extinction events according to the fossil record were five:

  • Ordovician-Silurian extinctions. Occurred 439 million years ago, which ended 85% of life at the time.
  • Devonian-Carboniferous extinction. Occurred 367 million years ago, which killed 82% of life on the planet.
  • Permian-Triassic extinction. The worst of all mass extinctions, occurred 251 million years ago and wiped out 96% of the world’s life.
  • Extinction of the Triassic-Jurassic. It took place 210 million years ago, as a result of the fragmentation of Pangea, and ended 76% of life at the time.
  • Cretaceous-Paleogene extinction. Happened 65 million years ago, it wiped out 75% of biological genera, especially dinosaurs.

Endangered Species

Ecology speaks of threatened species to refer to those that seem likely to be extinct in the near future. That is, those species that classify, within the NUIC Red List of Threatened Species, the groups of Vulnerable Species (VU), Endangered Species (EN) and Critically Endangered Species (CR), according to an order from lower risk to higher.

The criteria for evaluating the status of a species in this regard are based on the number of mature individuals the species has, as well as the rates of decrease in the number of total individuals (biomass) registered during the last 10 years or the last 3 generations of individuals.

Protected species

Extinct species - panda bear
The panda bear is one of the species that organizations seek to protect.

There is a group of species protected by international ecology organizations, which expressly prohibit their hunting, capture, possession or even the destruction of their habitat, given that they are generally endangered species. This is part of the efforts of numerous conservation organizations that try to prevent the total and definitive disappearance of these animal and plant species, thus defending the legacy of world biodiversity, that is, the variety of animal species that exist on the planet.

Some protected species are the Panda Bear (Ailuropodamelanoleuca), the black vulture (Aegypiusmonachus), the Mediterranean seal (Monachusmonachus) and the Iberian lynx (Lynx pardinus).

Examples of extinct animals

Extinct species - dodo bird
The Dodo bird was hunted to extinction in the late 17th century.

Some extinct animals due to their contact with the human species are:

  • The Dodo or Dronte bird (Raphuscucullatus). A very docile species of flightless land bird, which inhabited the Mauritius Islands, and whose absence of predators made it excessively vulnerable to the arrival of the human species, which hunted it to extinction at the end of the 17th century.
  • The Mexican Grizzly BearUrsusarctosnelsoni). A subspecies of brown bear that inhabited the Mexican states of Durango, Chihuahua, Sonora, and central Mexico, and whose last specimen was hunted by n utal HA Cluff in 1899.
  • The Japanese sea lion (Zalophusjaponicus)., Whose habitat was the archipelago of Japan until the bombings of the 2nd World War killed the species. The last specimen of the species was captured in 1974.
  • The Java Tiger (Panthera tigrisprobe). A subspecies of tiger from the Indonesian island of Java, assumed extinct since 1994.
  • The dolphin Baiji (Lipotesvexillifer). Also called the Chinese river dolphin, it lived in the Yangtze River, thanks to which it was nicknamed the “Yangtze Widow.” Its last specimen was sighted in 2007 and in 2008 it was declared extinct.
  • The Galapagos tortoiseChelonoidisnigra). An immense tortoise from the Galapagos Islands of Ecuador, capable of living for hundreds of years, disappeared with the death in 2012 of “George”, its last known living specimen.