Wombat skulls are changing in response to food

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Wombats’ jaws appear to change in relation to their diets, according to new research.

“The survival of wombats depends on their ability to chew large amounts of tough plants such as grasses, roots, and even bark,” says Vera Weisbecker, a fellow in the School of Biological Sciences at the University of Queensland.

“Climate change and drought are thought to make these plants even tougher, which might require further short-term adaptations of the skull. Scientists had long suspected that native Australian marsupial mammals were limited in being able to adapt their skull in this way,” Weisbecker says.

“But in good news, our research has contradicted this idea.”

The team used a technique known as geometric morphometrics—the study of how shapes vary—to characterize skull shape variation within three different species of wombat, with each species having a slightly different diet.

The researchers collected data with computed tomography—known to most as CT scanning—and analyzed them with new computation techniques.

Olga Panagiotopoulou, who co-led the research project from the Monash Biomedicine Discovery Institute, says the study suggested that short-term jaw and skull adaptation was occurring.

“This means that individual shapes are related to an individual’s diet and feeding preferences.

“It seems that individuals within each wombat species differ most where their chewing muscles attach, or where biting is hardest,” Panagiotopoulou says.

“This means that individual shapes are related to an individual’s diet and feeding preferences. Their skulls seem to be changing to match their diets.

“There are a number of factors that can influence skull shape, but it seems that wombats are able to remodel their jaws as the animals grow to become stronger and protect themselves from harm.”

Weisbecker says the team was particularly excited that the critically endangered northern hairy-nosed wombat, with around 250 individuals left, seemed to be able to adapt to new diets.

“In order to protect endangered animals, it’s sometimes necessary to translocate them to new sanctuary locations where threats are less, but diets may be quite different,” she says.

“Our findings suggest that future generations of these northern hairy-nosed wombats will adapt well to a different diet in a new home.

The researchers are planning to use a similar analysis on koala skull shapes.

The study is published in Frontiers in Zoology. Additional researchers from the University of Queensland, Monash University, the University of Liverpool, the University of Adelaide, and the University of Arkansas contributed to the research. Funding for the work came from the Wombat Foundation and the Australian Research Council.

Source: University of Queensland