China-Canada joint fossil discovery reveals dinosaur fight from 125 million years ago

An extraordinary story has emerged with the recent discovery of a rare fossil dating back approximately 125 million years ago, through joint efforts between Chinese and Canadian researchers. This fossil unveil a remarkable encounter where a large herbivorous dinosaur fell victim to an attack by a carnivorous mammal.

About the size of a large dog, the dinosaur fossil was identified as Psittacosaurus whereas the badger-like mammal fossil is an example of Repenomamus robustus, one of the largest mammals during the Cretaceous - a time when mammals had not yet become the dominant animals on Earth.

The two were found "locked in mortal combat," and "intimately intertwined," said Dr Jordan Mallon, the palaeobiologist with the Canadian Museum of Nature who handled the fossils.

The discovery of these two species Psittacosaurus and Repenomamus robustus was not a "novel finding" in and of itself, but the "predatory behaviour" on display is a rare find, Mallon emphasized.

Wu Xiaochun, a core figure on the project, told the Global Times that the fossils reveal the mammal was not feasting on an already dead dinosaur, but was actively attacking the animal.

"Similar articles that feature a predator mammal have been published before, but only until this one can we show it had its prey alive," said Wu, who is also the head of the Paleobiology Research and Collections Department of the Canadian Museum of Nature.
A typical case of a smaller predator attacking bigger prey, the fossils show, according to Mallon, that they had both lost their lives in the "roily aftermath."

While the fossil had been researched for years since it was first excavated in 2012 in Northeast China's Liaoning Province, the study was only published on Tuesday in Scientific Reports, a scholarly journal. Mallon is the co-author of the paper.

From excavation to publication, Wu played a pivotal role in bringing the researchers from China and Canada together for the project.

In 2012, the fossil was collected in Northeast China's Liaoning Province, more exactly from the Liujitun fossil beds, which are dubbed "China's Dinosaur Pompeii." After excavation, the fossils were in the care of study co-author Dr Han Gang in China, and later Wu helped Han connect with Mallon.

The research projects between China and Canada "will continue in 2023," Wu revealed to the Global Times.

"Joint research projects such as one on a marine reptile in Southwest China's Guizhou Province, is coming along," Wu said.

Diverse yeasts make their home on coffee and cacao beans

When your barista says today’s cuppa joe has rich, spicy notes found only in Colombia’s soil or ‘terroir,’ he or she might not be completely full of … beans.

Before going global, the coffee bean plant originated in Ethiopia, while cacao was first cultivated in the Amazon. Both coffee and cacao beans undergo fermentation prior to roasting. Wild yeast and other microbes that live on the bean digest the pulp that coats the beans, altering flavor and color as well. Researchers wondered, are these yeasts a product of the plants’ current geography or their original roots?

So, they bought unroasted coffee and cacao beans from 27 countries, isolated bean yeasts and analyzed the yeasts’ genes. While coffee and cacao yeasts are even more diverse than wine yeasts, strains that came from the same continents and countries had more in common genetically with their immediate neighbors. Still, some cacao strains from South America share genes with European vineyard yeast and North American oak tree yeast. Such hybrids are probably the result of human trade and travel, the team reports March 24 in Current Biology.

Determining the flavor fallout of all this yeast diversity requires further study, but wine yeasts from different locales are linked to specific chemical profiles.

A sperm whale’s head is built for ramming

The sperm whale is one of the odder-looking cetaceans swimming the oceans. Its massive, blocky head is unlike anything sported by other whales. The space above the mouth holds two large, oil-filled organs stacked one on top of the other — the spermaceti organ on top, and another below it called the (we did not make this up) junk. And in the last couple of decades, scientists have determined that the two organs amplify and direct the sonar clicks that the whales use to navigate in the water.

But there have long been suggestions that the massive head could serve another purpose — to ram other whales. The hypothesis dates back to the 19th century, when sperm whales sometimes rammed — and even sank — whaling vessels. “The structure and strength of the whale’s head is admirably designed for this mode of attack,” wrote Owen Chase, first mate of the Essex, which was sank by a whale and inspired the tale of Moby Dick.

Scientists have largely been leery of this hypothesis, though, in part because ramming would risk damage to organs used to generate sound, and because no one had seen a sperm whale ram another. Or at least no one had ever reported such an event in the scientific literature. But a new study, appearing April 5 in PeerJ, shows that Owen and his whaling buddies just may have been right.

Olga Panagiotopoulou of the University of Queensland in Australia and colleagues created computer simulations of a sperm whale’s head and what might happen when the head rammed another object. Partitions of connective tissue inside the junk, they found, appear to reduce the stresses created by impact, “and thus potentially function as a protective mechanism during ramming,” the team writes.

An impact creates tension in the connective tissue that serves as partitions between pockets of oil in the junk. That tension disperses the impact over a greater volume of the head, protecting both bone and soft tissue from injury. When the connective tissue was removed from the simulations, stresses increased by 45 percent and it became more likely that the skull would crack.

Scars on the heads of sperm whales tend to be around the junk, which may indicate that the whales avoid contact over the spermaceti organ — behind which is the whale’s sound generating system, the researchers note. So if the whales are ramming into one another, they probably can do so without hurting their ability to generate sonar clicks.

But are sperm whales really ramming each other? There is other evidence to suggest they just might be. For one, male sperm whales are as much as three times bigger than females, and such size differences are often found in species in which males compete through fighting. There are those sunken whaling ships, too, which add to the argument that ramming behavior may have been something natural for the whales.
But there’s also a report from a wildlife pilot who, on January 30, 1997, while flying over the Gulf of California, saw two males swim directly toward each other at a speed of about 17 kilometers per hour — and then collide, forehead to forehead.

Just before impact, the whales dove just below the surface of the water. That may explain why no one else has reported such sperm whale contests: If they’re occurring below the water’s surface, a person would have to be directly above the event, or in the water with the whales. And besides, if two 50-ton mammals are about to go head-to-head, it might be best to get out of the way.