Spring is a time for budding flowers, tender green leaves and baby animals. But 66 million years ago, that gentle season instead brought mass death and carnage from Earth’s catastrophic impact with a massive space rock.
Earth was forever changed after an enormous asteroid smashed into our planet at the end of the Cretaceous period (145 million to 66 million years ago), triggering a global extinction that wiped out 76% of life on Earth, including all nonavian dinosaurs, pterosaurs and most marine reptiles. Scientists recently pinpointed the season of the disaster and linked it to springtime in the Northern Hemisphere, after analyzing fossilized animals that died minutes after the impact.
They found the fossils at a site called Tanis, where a river once flowed through what is now North Dakota. After the asteroid struck near Mexico’s Yucatán Peninsula, the shock sent powerful waves roaring upstream toward Tanis, sweeping up fish and forest creatures and burying them alive under layers of soil. When the water subsided, it left behind an astonishingly well preserved 3D snapshot of destruction, captured within 30 minutes after the asteroid struck, the researchers reported in a new study. Fossils of those filter-feeding fish also held clues about their seasonal growth cycles, hinting that spring had sprung when the fish died and the dinosaurs‘ reign abruptly ended.
The moment of mass, instantaneous death preserved in Tanis, with broken and splintered fish fossils wrapped around tree branches and strewn in all directions, “was like the worst car crash you’ve ever seen, frozen in place,” said lead study author Melanie During, a doctoral candidate in the Department of Organismal Biology at Uppsala University in Sweden. It was also “the most spectacular deposit I’ve ever seen in my life,” During said at a news conference on Feb. 22.
During excavated Cretaceous fish at Tanis in August 2017, spending two weeks digging out fossils of paddlefish and sturgeons. Fish skeletons — even after fossilizing — retain records of an animal’s growth, which depends on seasonal food availability. By mapping these patterns in bone cell growth and density, the scientists hoped to identify which part of the growth cycle the Tanis fish had reached when they died, which could indicate what time of year it was.
The study authors scanned the fossils using synchrotron X-ray imaging, nondestructively imaging and reconstructing the fossils in 3D. They found tiny glass balls called spherules embedded in the fishes’ gills; these small spheres fused from ultrahot sediments when the asteroid struck and ejected towering plumes of dirt from the impact crater. Particles flew into Earth’s atmosphere and beyond and then rained back down on the planet as glassy beads.
An impact spherule from the Tanis event deposit. (Image credit: During et al. (2022))
Other researchers who studied Tanis’ Cretaceous death pit calculated that impact spherules would have fallen between 15 and 30 minutes after the asteroid crashed into Earth. Because spherules were in the fishes’ gills but had not been swallowed, the fish were likely buried alive immediately after inhaling the glassy beads — within 30 minutes after the asteroid impact, according to the new study.
Synchrotron scans also revealed signs of cell growth fluctuations in the fossilized bones, taking place over seven years. Much as trees mark the passage of time in the accumulation of rings, which are visible in cross sections of their trunks, fish add layers to their bones as they age, with growth peaking by the end of the summer and then declining over the winter. When the fish died, they were just entering a time of significant bone growth — which coincided with spring, study co-author Dennis Voeten, a research engineer at Uppsala University’s Department of Organismal Biology, said at the news conference.
“I think it makes sense to everyone that when a fish eats, its bone grows,” During told Live Science in an email. However, seeing this quantified in Cretaceous fossils “is really new and unbelievably informative for future studies,” she said.
A paddlefish from Tanis, prior to a scan at the European Synchrotron Radiation Facility in Grenoble, France. (Image credit: During et al. (2022))
Records of carbon isotopes, or variations of the element carbon, from one of the fishes further confirmed that the fish died in springtime, the scientists wrote in the study. Like bone growth, “the carbon isotope record shows a distinct cyclic pattern, where high values reflect high productivity of plankton,” which was the main food for paddlefish, said study co-author Jeroen van der Lubbe, an assistant professor in the Department of Earth Sciences at the Vrije Universiteit Amsterdam in the Netherlands. Plankton abundance is typically highest in summer; the isotope analysis showed that plankton productivity hadn’t yet peaked for the year, so the researchers concluded that the fish perished in the spring, van der Lubbe said at the news conference.
The timing of the asteroid impact likely had far-reaching consequences, with some species on Earth being better equipped to weather the disaster simply because of what season it was in their part of the world, the researchers reported.
Organisms in the Northern Hemisphere, where spring was warming things up, were likely just emerging and were primed for growth and reproduction after the cold winter months. They would have been exposed and had fewer resources, having already depleted whatever stored reserves helped them survive the winter. A springtime ecosystem could therefore have been more vulnerable to the immediate effects of the impact than plants and animals in the Southern Hemisphere that were hunkering down for winter, During said.
“After the impact, a sudden cooling of unknown duration took place — which, of course, had its own influence on the extinction pattern,” During said. “Nevertheless, it is clear that the organismal groups that did not survive that catastrophic spring/autumn would not have been around to fight in the subsequent nuclear winter to begin with.”
The findings were published online Wednesday (Feb. 23) in the journal Nature.
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.
