By Mark Kinver
The demise of big animals in the Amazon region 12,000 years ago cut a key way that nutrients were distributed across the landscape, a study has suggested.
Researchers say animals such as huge armadillo-like creatures would have distributed vital nutrients for plants via their dung and bodies.
The effects, still visible today, raise questions about the impact of losing large modern species like elephants.
The findings have been published in the journal Nature Geoscience.
A team of UK and US researchers developed a mathematical model to calculate what impact the sudden loss of megafauna - animals with a body mass of more than 44kg (97lb) - had on the Amazonia's ecosystem.
Results showed that the extinctions resulted in a 98% reduction in the dispersal of phosphorus (chemical symbol "P").
"This resulted in strong decreases in phosphorus availability in eastern Amazonia away from fertile floodplains, a decline that may still be ongoing," the scientists wrote.
"The current P limitation in the Amazon basin may be partially a relic of an ecosystem without the functional connectivity it once had." More....