Canberra, Aug 24 (IANS): A newly-discovered extinct species of kitten-sized lions that roamed the jungles of Australia 18 million years ago has been named after British broadcaster and naturalist David Attenborough.

"The UNSW discovery team has named the new species Microleo Attenboroughi for its small size and to honour Sir David Attenborough, in recognition of his support for the Riversleigh World Heritage Area, which he has described as one of the four most important fossil areas in the world," the University of New South Wales (UNSW) said in a statement on Wednesday.

The UNSW discovery team said the tiny marsupial lion was a new species that was unearthed at the Riversleigh World Heritage Area northwest of Queensland, Efe news reported.

"Microleo Attenboroughi would have been more like the cute but still feisty kitten of the family," UNSW's lead author Dr Anna Gillespie said.

"It was not lion-size or even bob-cat-size. Weighing only about 600 grams, it was more like a ringtail possum in size," she said.

The new species is thought to be much smaller than the other members of this extinct marsupial lion family, including its most famous but younger relative which is the lion-sized Thylacoleo carnifex.