A team of researchers said Wednesday that a fossilized nonavian dinosaur egg, discovered in western Japan in a stratum dating back 110 million years, has been recognized as the world's smallest by Guinness World Records.

The egg measuring about 4.5 centimeters by 2 cm, which researchers say likely belonged to a new species of theropod, was certified on May 23, when a journal article on its discovery was published online.

The fossilized egg estimated to have weighed only 10 grams, roughly the same as a quail egg, was found in a stratum dating back to the Early Cretaceous Period in Tamba, Hyogo Prefecture, according to the researchers from the University of Tsukuba and the Museum of Nature and Human Activities in Hyogo Prefecture.

As skeletal remains of small dinosaurs are far less common than those of larger ones such as the Tyrannosaurus, which was also a theropod, the discovery suggests that many different kinds of dinosaurs once roamed in what is now Japan, the team said.

"I hope people will know that a world-record dinosaur fossil has been found in Japan and ponder on the diverse types of dinosaurs in prehistoric times," said team member Kohei Tanaka, an assistant professor at the University of Tsukuba.