Molotopithecus may have eaten leaves instead of fruits
corbin rainbolt
The dense forests of eastern Africa began to give way to woodland 10 million years earlier than previously thought, facilitating the evolution of the upright apes that later gave rise to humans. That’s the conclusion of a team that has analyzed everything from ancient soil to fossilized ape bones at several sites in the region.
“One of the reasons we’re so confident in this story is that it’s based on multiple lines of evidence,” says Laura MacLatchy of the University of Michigan.
It is thought that the dense forests of eastern Africa began to transform into grasslands about 10 million years ago, and this change is thought to have prompted our ancestors to climb down from the trees and run across the savannah. .
However, MacLatchy and her colleagues have now analyzed fossil soils from several locations in Kenya and Uganda, revealing that C4 grasses were present up to 21 million years ago. More productive and drought tolerant than other grasses, C4 grasses are the main type found in grasslands.
“We found grass almost everywhere we looked,” says team member Danielle Peppe of Baylor University in Texas.
According to Peppe, the findings indicate a highly open forest area rather than pure grassland, with about 10 to 30 percent of the land covered by trees at the time. Yes, animals could not rely on fruit trees year-round like they do in the rainforest.
“These mutable environments existed twice as long ago as we thought,” says MacLatchy. “So we have to rethink our ape origins and our human origins.”
Ape predecessors walked on branches on all fours, limiting the use of their hands, as many animals still do today. But about 20 million years ago, some got bigger.
This meant I had to find other ways of locomotion, such as swinging my arms or holding on to someone else to stand on a branch, to get to the end of a small branch. “You need to distribute your weight over multiple supports, and a large person walking over branches can’t get there,” he says.
Importantly, these changes led to an upright posture in apes, paving the way for the later evolution of upright locomotion.
The conventional view is that it was fruit-eating apes that lived in uninterrupted forests that evolved this upright posture. But what MacLatchy and her team found included the teeth, jaws, and femurs of an ape called a monkey. Molotopithecus Challenge this idea that lived in this era.
The teeth suggest that this ape was a leaf-eating animal rather than a fruit-eating animal, but the short femur relative to body size, such as that of chimpanzees and gorillas, and other It shows the vertebrae previously found by the team standing upright. MacLatchy believes that these animals climbed to the tops of trees to reach young leaves and then traversed the ground to reach other trees. – of In other words, the upright posture is the result of the change to an open seasonal forest.
“MacLatchy and colleagues’ habitat reconstruction looks ironclad, but I remain cautious,” says Kevin Hunt of Indiana University Bloomington. Mandrills also have relatively short femurs, but walk on all fours, including branches, he says.
Hunt is particularly skeptical of the idea. Molotopithecus It primarily ate leaves, he says, but it may have eaten leaves during lean times.
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