Multinational research presented the first worldwide assessment of all terrestrial vertebrate species that have not been declared extinct, including more than 500 species that are deemed "lost," meaning nobody has observed them in more than 50 years.

Researchers reviewed information on 32,802 species from the International Union for Conservation of Nature Red List of Threatened Species (IUCN Red List) and identified 562 lost species.

Their findings appear in the journal Animal Conservation

The lost species
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(Photo : CHAIDEER MAHYUDDIN/AFP via Getty Images)

Extinct is defined by the IUCN Red List as "when there is no reasonable question that the last individual of a species has perished," which can be difficult to prove.

The Red List classified 75 of the 562 lost species as "possibly extinct," according to Simon Fraser University biodiversity professor and study co-author Arne Mooers.

The researchers noted that the existence of many species with an uncertain conservation status may become increasingly problematic as the extinction crisis worsens and more species go missing.

Since 1500, 311 terrestrial vertebrate species have been declared extinct, implying that 80% more species are thought to have lost than have been declared extinct.

With 257 species deemed gone, reptiles were first, followed by 137 species of amphibians, 130 species of mammals, and 38 species of birds.

The majority of these vanishing animals were last observed in megadiverse nations like Indonesia (69 species), Mexico (33 species), and Brazil (33 species) (29 species).

This concentration, while not surprising, is crucial, according to academics.

"The fact that the majority of these extinct species are found in megadiverse tropical nations is concerning, considering that these countries are predicted to face the largest number of extinctions in the future decades," said research lead author Tom Martin of Paignton Zoo in the United Kingdom, as per ScienceDaily.

Also Read: Vanished Into Thin Air: Top 4 Most Wanted Lost Species in the World

The dangerous decline

The IPBES Global Assessment's overwhelming evidence from a wide variety of domains of expertise paints an unpleasant picture, according to IPBES Chair Sir Robert Watson, as per United Nations.

Ecosystems on which humanity and all other animals rely are degrading at a faster rate than ever before.

The basic basis of our economy, livelihoods, food security, health, and quality of life are being eroded globally.

According to the report, it is not too late to make a difference, but only if we begin now at all levels, from local to global, he added.

Nature may still be saved, restored, and used sustainably through "transformative change," which is equally critical to achieving most other global goals.

The IPBES Plenary member States have now recognized that revolutionary change would inevitably face opposition from those with entrenched interests in the current quo, but that such opposition can be overcome for the greater good, according to Watson.

The IPBES Global Evaluation Report on Biodiversity and Ecosystem Services is the most formal assessment on the subject yet produced.

It is the first international report of its sort, and it expands on the historic Millennium Ecosystem Assessment of 2005 by providing new approaches to assessing evidence.

The Report, which was compiled over the course of three years by 145 expert authors from 50 countries with input from another 310 contributing authors, assesses changes over the last five decades, offering a holistic model of the relationship between industrial development pathways and environmental sustainability.

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