Two fossilized mandibles and several teeth found in northeastern Spain dating from 11.6 million years ago are the oldest remains found to date of ancestors of the giant panda, a team of Spanish paleontologists said in an article appearing in the journal PLOS ONE.
The team, headed by Juan Abella of the National Museum of Natural Sciences in Madrid, includes researchers from the Catalan Institute of Paleontology and several universities.
"The new genus we describe in this paper is not only the first bear recorded in the Iberian Peninsula, but also the first of the giant panda's lineage," Abella said.
Kretzoiarctos is the name Abella and his colleagues have given the new genus.
The fossils have the characteristics of a bear adapted to a diet of tough vegetation such as bamboo. Currently, the giant panda, which is native to certain parts of China, is the only member of this peculiar bear family that has a diet of this kind.
The position of the giant pandas on the evolutionary tree has been one of the most intensely debated matters among biologists who study mammals and paleontologists for more than a century.
The origin of the giant panda's genetic line has remained uncertain because of the scarcity of records from the Miocene period.
Until recently, the article explained, the genus Ailuractos from the Late Miocene in China, about 7-8 million years ago, was the oldest known member of the panda family.