Prehistoric fossil reveals ‘waves’ of extinction in Colombia

Fungal spores found in dung revealed that large animals died out in two “waves” in the Colombian Andes.

Spores of coprophilous fungi pass through the guts of megafauna (animals weighing more than 45 kg) as part of their life cycle, so the presence of spores in sediment samples indicates large animals living in a certain place and time.

A study by the University of Exeter found that the large animals died out locally in the Pantano de Monquentiva around 23,000 years ago and again around 11,000 years ago, with major impacts on ecosystems.

The study used samples from the Pantano de Monquentiva peat bog, located about 60 km from Bogotá in the Eastern Cordillera. This study was the first of its kind to be conducted in Colombia.

With biodiversity currently in crisis, the findings show how the extinction of large animals could once again transform the ecosystems that support wildlife and people.

“We know that large animals like elephants play a vital role in regulating ecosystems, for example by eating and trampling vegetation,” said Dr. Dunia H. Urrego of the Exeter Global Systems Institute.

“By analyzing fungal spores as well as pollen and charcoal samples, we were able to trace the extinction of large animals and the consequences of this extinction on plant abundance and fire activity.”

“We found that Monquentiva’s ecosystem changed dramatically when large animals disappeared, different plant species flourished and fires increased.”

Analysis of the fungal spores does not indicate which large animals were present, but known species to roam Colombia during this period include the giant armadillo and the six-meter-tall giant ground sloth.

The results show that the area was home to an abundant megafauna for thousands of years before disappearing completely around 23,000 years ago.

About 5,000 years later, megafauna began to inhabit the area again, perhaps in smaller numbers, before another wave of extinctions reduced it to near nothing about 11,000 years ago.

The cause of the extinction of these natives is unknown, but climate change and human hunting are two possibilities. Researchers have even suggested that a meteorite impact was the cause.

“Following the extinction of the megafauna, Monquentiva’s plant species changed to become more woody and palatable plants (those favored by grazing animals), and plants dependent on animal seed dispersal disappeared,” said first author Felix Pym, a research master’s degree. Student in Physical Geography at the University of Exeter.

“Wildfires became more common after megafauna disappeared, probably because flammable plants were no longer eaten or trampled.”

“Overall, our findings suggest that this habitat was highly sensitive to declines in its megafauna populations.”

The paper concludes that, given the current biodiversity crisis, conservation efforts must consider the effects of declining native herbivores on the distribution of certain plant species, fire activity, and the potential loss of ecosystem services (the value that humans derive from nature).

An article published in a journal Quaternary studiesentitled “Timing and ecological consequences of Pleistocene megafauna decline in the eastern Colombian Andes”.