![Simbakubwa kutokaafrika, a gigantic mammalian carnivore that lived 22 million years ago in Africa and was larger than a polar bear, is seen in this artist\'s illustration released in Athens, Ohio, U.S., on April 18, 2019. (Photo/Agencies)](http://www.ecns.cn/hd/2019/04/19/262d3ba41c98465dbb76338ad597506a.jpg)
Simbakubwa kutokaafrika, a gigantic mammalian carnivore that lived 22 million years ago in Africa and was larger than a polar bear, is seen in this artist's illustration released in Athens, Ohio, U.S., on April 18, 2019. (Photo/Agencies)
![Simbakubwa kutokaafrika, a gigantic mammalian carnivore that lived 22 million years ago in Africa and was larger than a polar bear, is seen in this artist\'s illustration released in Athens, Ohio, U.S., on April 18, 2019. (Photo/Agencies)](http://www.ecns.cn/hd/2019/04/19/55196af5c988467babe42413ef94a3dd.jpg)
Simbakubwa kutokaafrika, a gigantic mammalian carnivore that lived 22 million years ago in Africa and was larger than a polar bear, is seen in this artist's illustration released in Athens, Ohio, U.S., on April 18, 2019. (Photo/Agencies)