Modern humans have existed for thousands of years, however, recently some ancestral human fossils were found in China. Homo erectus are the skulls that were found and are the first relatives of the current generation to have human-like features. Their discovery made historians believe that they existed 600,000 years earlier than previously thought.

It was theorized that the Homo erectus originated in Africa, but they then left for Eurasia around 100,000 BC. The Homo erectus was originally believed to be around 1.1 million years old, but the recent discovery of the Homo erectus is 1.7 million years old, being way older, according to the Independent. Dr. Christopher Bae, a scientist who studied the fossil, said “These findings challenge long-held assumptions regarding when the earliest hominins are thought to have moved out of Africa and into Asia.”

According to Earth, the fossil is made of quartz, and a phenomenon called cosmic rays, high energy particles that strike the Earth in all directions, can give special information about the fossil. Another scientist, Dr. Hua Tu, a geologist at multiple colleges, states “Al-26 (aluminum-26) and Be-10 (beryllium-10) isotopes are produced when cosmic rays hit quartz minerals.” Particles of the cosmic rays work well with quartz and are used to date materials.

The skulls were preserved in Seoul, South Korea in the Han River. They were found on a terrace and were packed with sand to stop the aging process. This same material that preserved the Homo erectus skulls is also used for things such as stone weapons and animal remains and is best for preserving objects that are thousands of years old.

The Homo erectus has been around for more than a million years and could have been for even longer. They are the first human-like species on earth, and their found skulls are a big discovery.