A batch of newly discovered fossils come from prehistoric giant rhinos – the largest known land mammal in the history of the Earth.
Paleontologists discovered a complete skull from one rhino and three vertebrae from another, in the Linxia basin in the Gansu Province of northwestern China. The set of bones is 26.5 million years old.
Genetic analysis revealed that the fossils belonged to a species of giant rhino that scientists had never seen before. The team of researchers from China and the US dubbed the new animal “Paraceratherium linxiaense.”
“Usually fossils come in pieces, but this one is complete, with a very complete skull and a very complete jaw, which is rare,” Deng Tao, who led the team that discovered the fossils, told CNN. Deng is a professor at the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences.
Taller than a giraffe and roughly the size of six elephants, the rhino towered 23 feet above the ground, and its body was 26 feet long, Deng told CNN. It weighed roughly 24 tons. The skull was more than three feet long.
“It was very rare for a skull of that size to be preserved,” Deng said.
Deng and his colleagues shared their findings in a study published in the journal Communications Biology on Thursday.
A clue to the giant rhinos’ mysterious migrations
Scientists already knew about giant rhinos, or Paraceratherium, which have been found across Asia – mainly in Pakistan, Kazakhstan, Mongolia, and China.
But the new species, Paraceratherium linxiaense, shows that these prehistoric pachyderms made huge migrations across the continent.
In the early Oligocene era, 31 million years ago, giant rhinos moved out of the northern Tibetan plateau.
“Animal migration is linked to climate change. So 31 million years ago, when the Mongolian plateau dried up, they moved south,” Deng told CNN.
The new species, which is descended from those early migrants, indicates that giant rhinos made the trek back north during the late Oligocene. To get to Linxia, they would have had to cross the Tibetan plateau. According to Deng and his colleagues, this means the plateau must have been much lower than it is today.
“The weather got wet and they went back to the north,” Deng said. “Therefore, this discovery is of great significance to the study of the whole plateau-uplift process, climate, and environment.”
A ranger patrolling a watershed area east of Oakland, California discovered a trove of hundreds of fossils last summer from nearly a dozen ancient species. The site contains hundreds of petrified trees as well.
It’s one of the largest fossil finds in California history, and new fossils are still being unearthed there almost every day.
The discovery include fossils from prehistoric elephants with four tusks, mammoth-like mastodons, tortoises, and camels. The findingshave so far all been between 5 and 10 million years old.
The trove’s precise location remains a secret to protect the fossils and prevent looting.
The photos below show some of the findings so far.
Ranger Greg Francek was patrolling land in northern California last summer when he spotted a weird looking rock. “I was curious and had a closer look,” Francek told Insider.
The rock wasn’t a rock at all, but a petrified tree that was millions of years old.
“One end of the tree was partially exposed, and — to my surprise — I could see the tree rings,” Francek said.
The land Francek was patrolling is east of the San Francisco Bay — he has monitored watershed land for California’s East Bay Municipal Utility District (EBMUD) as a naturalist for more than a decade. Francek knew he’d come across something special, so he called paleontologist Russell Shapiro at California State University, Chico.
It wasn’t the first time Shapiro had been asked to look at potential fossils. “We get that call a lot,” he told Insider. But when Francek took Shapiro to see the ancient tree, they discovered a stunning trove of animal fossils.
“The very first day, I could look on the ground and go, ‘Well, that’s an elephant. That’s a rhinoceros. That’s a tortoise. That’s a camel,'” Shapiro said. “We found all this just by tripping over it.”
Shapiro knew it was an unprecedented discovery: Francek, it turns out, had stumbled across one of the largest fossil finds ever found in California.
“You kind of look around at the landscape and just think, ‘Oh, my god, there’s gonna be so much stuff here,'” Shapiro said.
In the 10 months since that first discovery, the duo has helped to unearth several hundred fossil specimens from nearly a dozen species. All are between 5 and 10 million years old.
Now, a team from EBMUD and CSU, Chico are steadily excavating the site. The fossils they’ve found offer a glimpse into an era of history known as the Miocene epoch, which occurred between 5 and 23.5 million years ago.
California looked quite different during the Miocene — there were no Sierra Nevada mountains, according to Shapiro, and dry grasslands were peppered with volcanoes. Still, the creatures that inhabited the land bore some resemblance to animals alive today.
Francek has discovered fossils of animals like rhinos, tortoises, and tapirs, which still exist, as well as extinct species like mastodons – shaggy, woolly mammoth-like beasts with tusks.
Shapiro recalled excavating a particular tapir jaw (pictured above) — he said he thinks tapirs are some of the cutest animals “because they look like a pig, but they have a nose like an elephant.”
Francek said it’s tough to pick a favorite fossil from the site, especially because he continues to find more whenever he visits.
“The giant camels are so cool. I like horses. And I like to think about the tortoises walking around the landscape like little armored tanks,” he said.
“I guess the creature that has my imagination working overtime is the gomphothere,” Francek added, “a four-tusked ancestor to the modern elephant.”
Gomphotheres were widespread in North America during the Miocene. They had tusks protruding from above and below their mouths.
Francek has found fossils from numerous gomphotheres, including an enormous, complete lower jaw and tusks.
That jaw, he said, “required 124 hours of excavation with hammer and chisel, and a tractor to lift it out of the ground.”
Shapiro said the team has unearthed countless herbivores but very few predator fossils. Ten months into the excavation, he said, “we’re just starting to find evidence of carnivores.”
In addition to fossils of weasel and fox relatives, they found evidence of bone-crushing dogs — prehistoric dog-like creatures that split off from the species that eventually became our pets.
These ancient dogs had strong jaws, Shapiro said: “They evolved the ability to chomp bone.”
He thinks these dogs were the dominant carnivores in the area millions of years ago, before they went extinct at the end of the Miocene.
The hundreds of fossilized trees found at the site so far can help scientists understand what happened to California’s climate at the end of the Miocene.
During those years, the Earth was starting to get colder, paving way for the first global ice age 2.4 million years ago.
“We can really tell that the temperatures were starting to drop quickly,” Shapiro said. “Right before this period, you find more tropical plants in California and elsewhere. And then right around this time, you’re seeing the spread of oaks and other plants like redwood trees that really prefer a cooler climate.”
Shapiro and Francek think the trove has more to offer. Francek said he’s been back to the site almost every day since last summer looking for new finds.
When he discovers something new, Francek takes photos, documents the location, contacts Shapiro, and starts trying to figure out what the critter might be. Recently, he uncovered a mastodon skull, complete with its tusks, fossilized in a rock.
“Every time he goes out, he finds something new, Shapiro said. “I’m getting used to him texting me photos almost every day.”
Once fully excavated, the fossils get taken to a lab in Chico. Shapiro said the team has finally secured a lab large enough to properly study all the findings. They’re working to count them and date the fossils more precisely.
“All of these bones come from pretty much one geologic layer,” Shapiro said.
That suggests the ancient creatures were fossilized around the same time.
The trove’s precise location remains a secret, however, in order to keep the area safe from vandals and looters.
Since excavations are ongoing, EBMUD does not allow the public to visit the site. Instead, it has set up an online tour of the findings for users to explore.
The secrecy is warranted: After Francek’s initial discovery, Shapiro recalled the ranger’s excitement at the prospect of showing him that first petrified tree. But when they arrived part of it was missing.
“It was like a punch to the gut to find that some of the petrified tree remains had been stolen and vandalized,” Francek said.
After that, the team quickly secured the remaining specimens and installed an around-the-clock patrol of the site.
“We intentionally waited nearly a year to announce the discovery so that we could establish solid security measures,” Francek added.
Ulla Mannering and Charlotte Rimstad are used to studying textiles, not bones. Since 2018, they’ve helped reconstruct Viking-age clothing at the National Museum of Denmark by analyzing fabric from ancient burial sites. But recently, they stumbled across a box of human remains.
These weren’t your average bones, they quickly realized.
“We looked at each other and said, ‘OK, we think we have the Bjerringhøj bones actually here,'” Mannering told Insider, referring to bones from the Bjerringhøj burial mound in northern Denmark.
The gravesite likely dates back to around 970 AD. This particular set of bones is believed to have been lost for more than 100 years.
In 1868, a farmer happened upon the burial mound while collecting soil, only to discover human remains sitting atop a pile of down feathers. The deceased person, presumably a man, had been draped in wool garments woven with gold and silver threads. In his chamber were two iron axes, a beeswax candle, two wooden buckets, and a bronze kettle.
Local farmers looted the artifacts, though they were eventually recovered and sent, along with the bones, to the National Museum of Denmark. But at some point many decades ago, the bones went missing.
“We can now show that they were not really lost, but they were just misplaced in the museum,” Mannering said. “It’s a nice ending.”
Archaeological studies of the bones may just be getting started. In a new study in the journal Antiquity, Mannering and Rimstad suggest that the man was an elite – perhaps even royalty – based on the clothing and artifacts buried alongside him.
“There are so many details in this grave that place him in the absolute top part of Viking-age society,” Mannering said. “But who he was – we don’t know.”
Why did the bones go missing?
In 1986, archaeologists excavated the Bjerringhøj burial mound a second time. Before examining the site, they hunted for the lost bones in the National Museum of Denmark’s collection. But the remains never turned up, and the burial site was found to be mostly empty, save for a few fragments of textile and feathers. Researchers again combed through the museum’s collection in 2009 – but no luck.
Mannering said it’s rare for bones to simply get lost. But over the years, as the museum changed staff or moved the collection to different storage areas, it’s possible that the remains were placed on the wrong shelf and separated from the rest of the Bjerringhøj artifacts.
In her experience, she said, even archaeologists can be somewhat skittish about handling human remains, so that might explain why they wound up separated from other objects found at the site.
“Human remains like bones and skeletons and even bog bodies, though we find them fascinating today, have had a very sort of ambivalent life in many museums because they were not really considered as objects,” Mannering said. (Bog bodies are human cadavers that have been naturally preserved by acid from dead plants.)
She added: “In the past, the idea of keeping human remains as an object was against the general idea that your body has an afterlife. Even today, there are a lot of people who resent the idea that some museums exhibit bog bodies.”
Textiles suggest the man was very wealthy
To prove they’d rediscovered the lost bones of Bjerringhøj, Mannering and Rimstad used radiocarbon dating – a method that determines the age of an artifact based on how much carbon-14, a radioactive isotope, it contains. The process showed that the bones dated back to the late 10th century, around the same time that Vikings raided and colonized Europe.
The researchers also found that the textiles wrapped around the bones matched those previously discovered at the Bjerringhøj site.
In particular, woven fabric tied around a leg bone suggested that the man wore long trousers with ankle cuffs. The textiles closely resemble a pair of woven arm cuffs that were also preserved by the museum.
“He’s a very rich man,” Mannering said. “He has a lot of status symbols in his grave and his costume is really high status. He has very unusual tablet-woven bands made of silk and gold and silver threads.”
The new analysis suggests that the man was older than 30 and had knee problems, perhaps from riding horses.
Based on the textiles and an old description of the bones from 1872, past research proposed that the man may have belonged to the Jelling dynasty, a royal house that reigned over Denmark, England, and Norway in the early 11th century. But Mannering said researchers still doesn’t know whether he was a royal at all.
The bones also aren’t preserved well enough to perform a DNA analysis, so the researchers can’t confirm the man’s sex.
“The grave has always been seen as a male grave because it has the two axes – a plain iron axe and this very, very elaborately decorated axe with a silver inlay,” Mannering said.
It’s possible, though, that the bones belonged to a woman, or that a man and woman were buried together.
“We’ve brought the bones into context again,” Mannering said. She added, “Maybe in the future, somebody else will be able to do other analyses on these finds.”