Light shed on koala evolution

Feb 02, 2010
Light shed on koala evolution
Lowland mid Tertiary rainforest of Queensland, Australia, including archaic koalas that reveal evidence about the origin of their distinctive vocalizations. Artwork by Dorothy Dunphy courtesy of Louise Egerton.

(PhysOrg.com) -- The world at large knows koalas as cute, cuddly, lovable iconic animals. The evolutionary biologist, on the other hand, will know them as extremely specialized, endangered animals, the evolutionary history of which is extremely poorly understood.

Recently discovered skull material belonging to the extinct Litokoala and Nimiokoala offers a major step forward in understanding koala evolution, according to a new study published in the . The study, which was carried out by a team led by Dr. Julien Louys of the University of New South Wales in Sydney, Australia, focused on the evolution of the masticatory (chewing) apparatus and hearing.

At the time these extinct koalas lived, the Australian continent was wetter and much more forested than it is today. As the continent dried out and the flora became dominated by plants with hard, tough leaves, animals such as koalas had to adapt to this new food resource. The team led by Dr. Louys found that the chewing apparatus of the living koala is much more specialized than its fossil forebears, including adaptations for more powerful bite forces and the ability to shred the tough leaves of the eucalypts that are the mainstay of its diet.

In contrast, analysis of the suggests that differences between the fossil and living koalas are relatively small. This indicates that the specialized loud and complex vocalizations of living koalas - a trait unusual among marsupials - likely have an ancient origin. The study therefore shows that the chewing apparatus and hearing adaptations in living koalas evolved at different times and under different environmental circumstances, an indication that adaptations, even in the most specialized animals, may have disparate origins and evolve in mosaic fashion.

Explore further: Mammalian bones provide clues to early human activity

Provided by Society of Vertebrate Paleontology

4.4 /5 (13 votes)
add to favorites email to friend print save as pdf

Related Stories

Loud and lazy but didn't chew gum: Ancient koalas

Dec 19, 2009

(PhysOrg.com) -- Skull fragments of prehistoric koalas from the Riversleigh rainforests of millions of year ago suggest they shared the modern koala's "lazy" lifestyle and ability to produce loud "bellowing" ...

Vaccine for koala chlamydia close

Jul 17, 2008

Professors Peter Timms and Ken Beagley from Queensland University of Technology's Institute of Health and Biomedical Innovation (IHBI) said the vaccinated koalas, which are at Brisbane's Lone Pine Koala Sanctuary, were mounting ...

Research finds koalas are no dwarves

Dec 11, 2008

(PhysOrg.com) -- University of Queensland research has found one of Australia's iconic animals is not a shadow of its former self.

Vaccine trials inject hope into koala's future

Jul 16, 2007

The first Australian trials of a vaccine developed by Queensland University of Technology that could save Australia's iconic koala from contracting chlamydia are planned to begin later this year.

Recommended for you

New progress of the Neogene Suidae research

Oct 17, 2014

Dr. Hou Sukuan and Prof. Deng Tao from the Institute of Vertebrate Paleontology and Paleoanthropology(IVPP), Chinese Academy of Sciences reported a new species of Chleuastochoerus from the Linxia Basin, Gansu ...

User comments : 0