Compared to the massive, magnificent dinosaurs of the Mesozoic era, ancient mammals are often thought of as little more than beady-eyed pipsqueaks scurrying around in the larger reptiles’ shadows. But now an exquisitely preserved fossil from northeastern China shows that sometimes, the mammals bit back.
The fossil consists of two, nearly complete fossilized skeletons that have been intertwined for approximately 125 million years. The larger skeleton belongs to a dog-size, plant-eating dinosaur known as Psittacosaurus. The smaller skeleton atop the dinosaur belongs to Repenomamus robustus—a meat-eating mammal that would have been about the size of a badger.
“The mammal is gripping the lower jaw of the dinosaur, and it’s kind of holding the dinosaur down and biting into its ribs,” explains Jordan Mallon, a paleobiologist at the Canadian Museum of Nature and co-author of the new study describing the find, published in the journal Scientific Reports.
“I remember when I first looked at it,” he says. “My jaw dropped and my eyes bulged out of my head, because it’s such a fantastic fossil.”
The mammal-vs-dino fossil hails from a rocky outcrop known as the Lujiatun Member of the Lower Cretaceous Yixian Formation—or what some scientists refer to as “Chinese Dinosaur Pompeii,” due to the heavy amount of volcanic activity in the area at the time. With ash build up everywhere and seasonal rains, it’s thought that mudslides were common—and extremely sudden.
“They sort of come out of nowhere,” says Mallon, who has experienced similarly slippery conditions during field work in Alberta, Canada. “These volcanic mudflows would habitually wipe out the animals living in the environment, including this new fossil we described.”
The dinosaur and mammal were instantaneously covered in ash and mud, preserving the details of their mortal struggle.
“I’ve never seen anything like it before,” says Stephen Brusatte, a University of Edinburgh vertebrate paleontologist and author of The Rise and Reign of the Mammals.
“Preserving any part of an animal for 125 million years is hard enough,” says Brusatte, who was not involved in the new study. “But capturing two animals locked in combat, it seems like a miracle.”
Mammal vs. dino: Anatomy of an attack
While the experts assumed from the start that the fossil depicted a mammal attacking a dinosaur, they wanted to be sure.
“It looks for all the world like a predation event,” says Mallon. “But we didn’t want to take that for granted. We’re scientists, right?”
The fossil could show a mammal scavenging at the carcass of a recently deceased dinosaur. To rule that scenario out, the experts point to three factors.
First, the Psittacosaurus bones showed no signs of scraping or gnawing. “Mammals today, when they’re scavenging a carcass, let’s say on the plains of the Serengeti, they’ll very often leave bite marks on the bones,” says Mallon. “And there’s just no signs of any bite marks on the bones.”
Second, Repenomamus is perched atop the dinosaur, as though it is trying to hold it down and finish it off. This positioning is much less likely for a scavenging mammal, reason the scientists.
“And lastly, the sort of clincher for me is the fact that the hind leg of the mammal is sort of trapped within the folded hind leg of the dinosaur, which could only have happened if the dinosaur had collapsed down onto the mammal,” says Mallon. “And that can’t happen unless the dinosaur is still alive.”
Brusatte agrees with the authors’ conclusion. “The two animals are intertwined. The meat-eater has its teeth and claws sunk into the plant-eater. I mean, these critters aren’t giving each other a hug or dancing a waltz. What else could they be doing?” he says.
Rethinking Mesozoic mammals
While it may seem unusual that a six-pound mammal would attack a dinosaur around three times its size, it’s also not as unlikely as you might think.
“Modern-day carnivores can successfully hunt animals much larger than them by themselves,” says Nuria Melisa Morales Garcia, a vertebrate paleontologist at the University of Bristol in the United Kingdom.
For instance, weasels are known to take down prey up to 10 times their own size, and wolverines sometimes hunt animals as large as moose and caribou.
“We don’t really know if this individual of Repenomamus would’ve successfully killed the dinosaur if it weren’t from the volcanic flow that caused their deaths, or if it was common for Repenonamus to successfully hunt and kill adult Psittacosaurus,” says Morales Garcia, who was not affiliated with the new study. “But it is certainly convincing that these two animals were locked in a struggle.”
This is also not the first time these animals have shown up in a fossil together. A 2005 study published in Nature described a Repenomamus fossil with a juvenile Psittacosaurus in its belly.
“Our understanding of Mesozoic mammals has changed so much in the past few decades,” says Morales Garcia. “There’s already a large number of studies out there that have shown us that mammals were thriving during the Mesozoic. They were swimming, they were gliding, they were climbing—they were eating dinosaurs!”
NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.
Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.
She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.
Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.
“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.
It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.
Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.
Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.
“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.
He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.
Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
