A new study has revealed that our ancient ancestor Homo erectus survived a lot longer than previously believed. According to new dating evidence, the species survived on the Indonesian island of Java until just over 100,000 years ago – much longer than after it disappeared from other areas.
Homo erectus first appeared approximately two million years ago and they were the first human ancestors who were able to walk completely upright.
Two lower leg bones and twelve skull caps belonging to Homo erectus were discovered in a bone bed located 20 meters above the Solo River at Ngandong in central Java in the 1930s. While researchers had a tough time, they were finally able to come up with an approximate date of the fossils. Initially, researchers believed that the fossils dated back to between 53,000 and 27,000 years ago, which put into question the possibility that our ancient human ancestors somehow overlapped with more modern humans living on Java.
More recently, however, new excavations led by Professor Russell Ciochon from the University of Iowa have been underway beside the Solo River to reanalyze the area. By studying records from the initial search conducted by the Dutch team in the 1930s, researchers were able to conduct new excavations at the same site where the Homo erectus bone bed had been discovered. Pictures can be seen here.
According to their studies, they have dated the bone bed to between 117,000 and 108,000 years old. This new research provides the most recent record of the Homo erectus species living on the planet. Their results were published in the journal Nature and can be read in full here.
“This is a very comprehensive study of the depositional context of the famous Ngandong Homo erectus partial skulls and shin bones, and the authors build a strong case that these individuals died and were washed into the deposits of the Solo River about 112,000 years ago,” stated Professor Chris Stringer, who is a research leader on human evolution at London’s Natural History Museum. He went on to say, “This age is very young for such primitive-looking Homo erectus fossils, and establishes that the species persisted on Java for well over one million years.”
The large number of bones found could have been the result of mass death. The mass casualties could have been caused by a lahar upriver which is when heavy rainfall after an eruption causes a hot or cold mixture of rock fragments and water to flow down the sides of a volcano. These violent mudflows destroy everything in their paths and definitely have the power to cause mass death.
The remains found at Ngandong reveal that they were between 5 and 6 feet tall – similar to remains discovered in Africa as well as in other parts of Eurasia. As for why Homo erectus survived so much longer on Java compared to other places (they were eliminated from Africa around 500,000 years ago and approximately 400,000 years ago in China), it was probably because they were isolated on the island and had no competition with other species.