The discovery of a 2-million-year-old skull in South Africa may provide more answers to human evolution, Australian researchers said.
The skull that was of a male Paranthopus robustus, a “cousin species,” to Homo erectus, a species thought to be direct ancestors of modern humans. According to researchers, the two species lived around the same time but, Paranthropus robustus died out earlier.
The discovery of the skull was remarkable, according to the very excited research team. ”Most of the fossil record is just a single tooth here and there so to have something like this is very rare, very lucky," Dr Angeline Leece told the BBC.
The skull’s fragments were first found in 2018 at the Drimolen archaeological site north of Johannesburg by researchers from Melbourne's La Trobe University. It was uncovered just meters away from a spot where a similarly aged Homo erectus skull of a child was discovered in 2015, the news outlet reported.
Archeologists spent the last few years piecing together and analyzing the fossil.
On Tuesday, their findings were published in the Nature, Ecology and Evolution journal.
Co-researcher Jesse Martin told the BBC that handling the fossil pieces was like working with "wet cardboard", adding he had used plastic straws to suck the last traces of dirt off them.
Martin pointed out that three hominins, or human-like creatures, lived in South Africa at the same time in competition with each other. He explained that the skull discovery presented a rare example of “microevolution” within the human lineage.
For instance, the Paranthropus robustus was noted to have large teeth and small brains. Their diets consisted of mainly tough plants, like tubers and barks. Meanwhile, Homo erectus had large brains and small teeth. Their smaller teeth was more likely to have eaten both plants and meat.
Leece told the BBC that through time, Paranthropus robustus likely evolved to withstand biting and chewing food that was hard or mechanically challenging to process with their jaws and teeth.
"These two vastly different species... represent divergent evolutionary experiments," Leece said.
"While we were the lineage that won out in the end, two million years ago the fossil record suggests that Paranthropus robustus was much more common than Homo erectus on the landscape."