Kangaroos hop, right? Well, not all of them.
Scientists said on Wednesday that a biomechanical and statistical analysis of fossil bones of a group of huge extinct kangaroos shows that the largest of the bunch in all likelihood could not hop as their modern-day relatives do with aplomb.
The study focused on a group of big-bodied, short-faced kangaroos called sthenurines that lived in Australia from about 13 million years ago until about 30,000 years ago, disappearing after the first humans arrived on the continent.
Photo: Reuters
These kangaroos were more heavily built than modern ones and had faces reminiscent of a rabbit. The largest, a species called Procoptodon goliah, weighed about 240kg, stood 2m tall and was 3m long.
The study found important anatomical differences in sthenurines’ limb bones compared with other kangaroos.
In terms of locomotion, they were unlike today’s kangaroos, with an anatomy ill-suited for hopping. They likely walked in an upright bipedal stance — putting one foot in front of the other, just like people — in a way modern kangaroos cannot, the study found.
This was facilitated by larger hips and knee joints as well as stabilized ankle joints, unlike today’s kangaroos, but like animals that walk or run. They also had a relatively inflexible spine not conducive for hopping.
“Today’s kangaroos mostly use hopping as their fast gait — although tree kangaroos rarely hop. But for slow speeds they use a type of ‘pentapedal’ walk, using all four legs and the tail,” said Brown University paleontologist Christine Janis, who led the study published in the scientific journal PLOS ONE.
With their stiff backs and specialized hands, this “pentapedal” gait would have been difficult for sthenurines. They also lacked certain specialized anatomical features of modern large hopping kangaroos, the researchers said.
Janis said she suspected smaller sthenurines used bipedal walking at slow speeds and may have switched to hopping at faster speeds.
“But the largest ones may have walked rather than hopped most if not all of the time,” Janis said.
Virtually all kangaroos today hop, although a species called the musky rat-kangaroo does not.
Australia is famous for its marsupials — mammals that carry newborns in a pouch on the mother’s abdomen, including kangaroos, koalas, wombats and others.
Procoptodon, the largest known kangaroo, lived from about 125,000 years ago to 30,000 years ago.
“Something the size of Procoptodon would have had a hard time hopping, if it hopped at all,” Janis said.
“Research on living kangaroos shows that they are close to the limit in terms of tendon strength while hopping,” she added.
Procoptodon lived alongside animals like the nearly hippopotamus-sized herbivorous marsupial Diprotodon, the “marsupial lion” Thylacoleo and the giant monitor lizard Megalania that measured roughly 7.5m long.
Scientists say Procoptodon and its group went extinct possibly because of hunting by humans, who arrived in Australia about 50,000 years ago, environmental changes wrought by people or climate changes.
Chinese President Xi Jinping (習近平) is to visit Russia next month for a summit of the BRICS bloc of developing economies, Chinese Minister of Foreign Affairs Wang Yi (王毅) said on Thursday, a move that comes as Moscow and Beijing seek to counter the West’s global influence. Xi’s visit to Russia would be his second since the Kremlin sent troops into Ukraine in February 2022. China claims to take a neutral position in the conflict, but it has backed the Kremlin’s contentions that Russia’s action was provoked by the West, and it continues to supply key components needed by Moscow for
Japan scrambled fighter jets after Russian aircraft flew around the archipelago for the first time in five years, Tokyo said yesterday. From Thursday morning to afternoon, the Russian Tu-142 aircraft flew from the sea between Japan and South Korea toward the southern Okinawa region, the Japanese Ministry of Defense said in a statement. They then traveled north over the Pacific Ocean and finished their journey off the northern island of Hokkaido, it added. The planes did not enter Japanese airspace, but flew over an area subject to a territorial dispute between Japan and Russia, a ministry official said. “In response, we mobilized Air Self-Defense
CRITICISM: ‘One has to choose the lesser of two evils,’ Pope Francis said, as he criticized Trump’s anti-immigrant policies and Harris’ pro-choice position Pope Francis on Friday accused both former US president Donald Trump and US Vice President Kamala Harris of being “against life” as he returned to Rome from a 12-day tour of the Asia-Pacific region. The 87-year-old pontiff’s comments on the US presidential hopefuls came as he defied health concerns to connect with believers from the jungle of Papua New Guinea to the skyscrapers of Singapore. It was Francis’ longest trip in duration and distance since becoming head of the world’s nearly 1.4 billion Roman Catholics more than 11 years ago. Despite the marathon visit, he held a long and spirited
China would train thousands of foreign law enforcement officers to see the world order “develop in a more fair, reasonable and efficient direction,” its minister for public security has said. “We will [also] send police consultants to countries in need to conduct training to help them quickly and effectively improve their law enforcement capabilities,” Chinese Minister of Public Security Wang Xiaohong (王小洪) told an annual global security forum. Wang made the announcement in the eastern city of Lianyungang on Monday in front of law enforcement representatives from 122 countries, regions and international organizations such as Interpol. The forum is part of ongoing