Washington, June 24 : A new study has suggested that despite their vastly different sizes, ancient wombats that roamed Australia about two million to 10,000 years ago, all belonged to the same species, and that gender differences accounted for the huge size gaps in the creatures.
According to a report in National Geographic News, the ancient wombats were 9 feet (3 meters) long and 70 inches (180 centimeters) tall. Some of the marsupials weighed as much as a pickup truck and stood as tall as a person.
Today's wombats, found throughout much of southern Australia, are more modest in appearance-short-legged, plant-eaters about 3.2 feet (1 meter) long. They hardly resemble their giant Ice Age ancestors, the largest marsupials to roam Earth from about two million to 10,000 years ago.
Scientists came forward with the latest theory that only one giant wombat species existed, by analyzing fossil teeth of giant wombat specimens.
"I suspected that just looking at teeth might give a much clearer picture of who was related to who," said study author Gilbert Price, a paleontologist of the University of Queensland in Brisbane, Australia.
"I figured the study would reveal that two, maybe three species once roamed the continent," he added.
Unlike the rest of the body, which is subject to the demands of sexual display, back teeth such as molars tend to only be involved in eating. Since both sexes of a particular species usually eat similar foods, their teeth should look the same.
Price leveraged this fact while comparing more than a thousand ancient wombat teeth held in museums around the world.
He discovered that the fossils all showed similar patterns.
This indicated just one giant wombat species existed and that paleontologists were mistaking the differently sized male and female giant wombats for separate species.
The discovery also helps explain why the bones of different-size wombats-male and female-are often found together.