Stone Age Tool Discovery Raises Questions about Who Used Them

Stone Age Tool Discovery Raises Questions about Who Used Them

Scientists have discovered some of the oldest stone tools ever found at a research site in Kenya. But the find created a mystery about which group of early humans made and used the tools.

A study recently published in Science suggests early humans used the tools to cut up animals for food about 3 million years ago.

In the past, scientists thought our direct ancestors were the ones making and using tools. But two teeth from an extinct¹ human-like creature were found at the site. This led researchers to believe that other kinds of hominins might have picked up tools too.

The term hominin is still developing and is used to describe species² that are considered human or closely linked to humans.

The team said the newly found tools are probably the oldest example of what is known as the Oldowan toolkit. This was a set of tools that spread across Africa and beyond during the Stone Age.

Rick Potts is the director of the Smithsonian's Human Origins Program. He told the Associated Press that he thinks the find adds to existing evidence that our direct ancestors may not have been the only users of Stone Age technology.

"Those teeth open up an amazing whodunit³ – a real question of, well, who were these earliest toolmakers?" Potts said.

The researchers said the tools date back to about 2.9 million years ago, when early humans used them to cut up hippopotamuses⁴ and other big animals for food. The study suggests these kinds of tools were widely used earlier than had been believed.

Three kinds of tools were found. These included some with flat sides believed to have been used to crush plants, bone and meat. Others had sharp edges for cutting meat.

Thomas Plummer is with Queens College of the City University of New York and was the lead writer of the study. He told the AP that, with the tools found, early humans could cut and crush a wide range of materials. In addition, he said tools from the Kenyan site also suggested they had assisted early humans with eating.

The site, known as Nyayanga, is in a hilly area on the shores of Lake Victoria. Since starting work there in 2015, researchers have also found many objects and animal bones.

Plummer said cut marks on several hippo bones show they were cut up for their meat. The early humans also likely used the tools to break open antelope⁵ bones to get out marrow⁶ and tissue inside the bones, the study said.

Plummer added that the stone tools permitted the early humans to get and process a lot of necessities from the environment. "If you can butcher a hippo, you can butcher pretty much anything," he said.

Words in This Story

site –n. a place where something is or was

extinct – adj. not existing anymore

whodunit – n. a story, book or movie about a mystery and its solution

butcher – v. the act of cutting up meat

1 extinct   

adj.灭绝的，不再活跃的，熄灭了的，已废弃的

参考例句：

• All hopes were extinct.所有希望都破灭了。
• Dinosaurs have been extinct for millions of years.恐龙绝种已有几百万年了。

2 species   

n.物种，种群

参考例句：

• Are we the only thinking species in the whole of creation?我们是万物中惟一有思想的物种吗？
• This species of bird now exists only in Africa.这种鸟现在只存在于非洲。

3 whodunit   

n.侦探小说（或剧本、影片等）

参考例句：

• It is not the most promising script for a whodunit.这并不是最有市场前景的侦探小说剧本。
• I always like the series "Whodunit" by Wei Sili.我一直很喜欢卫斯理系列的推理小说。

4 hippopotamuses   

n.河马（产于非洲）( hippopotamus的名词复数 )

参考例句：

• Hippopotamuses teem in this river. 这条河里有很多河马。 来自《简明英汉词典》

5 antelope   

n.羚羊；羚羊皮

参考例句：

• Choosing the antelope shows that China wants a Green Olympics.选择藏羚羊表示中国需要绿色奥运。
• The tiger was dragging the antelope across the field.老虎拖着羚羊穿过原野。

6 marrow   

n.骨髓；精华；活力

参考例句：

• It was so cold that he felt frozen to the marrow. 天气太冷了，他感到寒冷刺骨。
• He was tired to the marrow of his bones.他真是累得筋疲力尽了。