When were giant armadillos and giant sloths wiped out?

By Mark Waghorn via SWNS

Giant armadillos, sloths and other massive beasts were wiped out in two waves in the Colombian Andes during the last ice age, according to new research.

The mysterious local extinctions may have been caused by climate change, hunting by humans or even a meteorite strike.

The extinctions had a dramatic effect on ecosystems - with implications for global warming and deforestation today.

Dr. Dunia Urrego, of Exeter University, UK, a co-author of the study, said: "We know large animals such as elephants play a vital role in regulating ecosystems, for example by eating and trampling vegetation.

"By analyzing samples of fungal spores, as well as pollen and charcoal, we were able to track the extinction of large animals, and the consequences of this extinction for plant abundance and fire activity.

"We found the Monquentiva ecosystem changed dramatically when large animals disappeared, with different plant species thriving and wildfires increasing."

The evidence comes from an analysis of prehistoric poop. Spores known as coprophilous fungi pass through the guts of megafauna as part of their life cycle.

Their presence shows animals over 45kg (99lbs) lived in a certain place and time.

The new study, the first of its kind, shows they vanished locally from Pantano de Monquentiva about 23,000 years ago - and again about 11,000 years ago.

Sediment samples were collected from a peat bog located about 37 miles from Bogota in the eastern cordillera.

With biodiversity now in crisis, the findings highlight how the disappearance of large animals could once again transform ecosystems that sustain wildlife and humans.

Analysis of the fungal spores does not show which large animals were present.

But species known to roam Colombia in this period include the giant armadillo and the six-meter-tall giant ground sloth.

The findings show that plentiful megafauna existed in the area for thousands of years, then disappeared entirely about 23,000 years ago.

About 5,000 years later, megafauna began to live in the area again - likely at lower numbers - before another wave of extinction about 11,000 years ago reduced them almost to zero.

Felix Pym, a master's student at Exeter and another of the study's authors, added: "After the megafauna vanished, plant species at Monquentiva transitioned, with more woody and palatable plants, those favored by grazing animals, and the loss of plants that depend on seed dispersal by animals.

“Wildfires became more common after the megafauna extinctions – presumably because flammable plants were no longer being eaten or trampled upon.

“Overall, our findings show that this habitat was highly sensitive to the decline of its megafaunal populations."

Current conservation efforts must account for the effects of local herbivore declines on the dispersal of certain plant species, fire activity and the potential loss of ecosystem services - the value humans gain from nature.

The study was published in the journal Quaternary Research.