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Morocco dinosaur discovery gives clues on why they went extinct

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66 million years ago, the last dinosaurs vanished from Earth. We’re still trying to understand why. New fossils of abelisaurs – distant relatives of the tyrannosaurs – from north Africa suggest that African dinosaurs remained diverse up to the very end. And that suggests their demise came suddenly, with the impact of a giant asteroid.

The causes of the mass extinction have been debated for two centuries. Georges Cuvier, the father of palaeontology, thought extinction was driven by catastrophes. Charles Darwin thought gradual changes in the environment and competition between species slowly drove lineages extinct.

As our understanding of the fossil record improved, it became clear that the Cretaceous period (145 million years to 66 million years ago) ended with an extraordinary wave of extinction. Huge numbers of species disappeared, worldwide, in a brief period. The discovery of the 180km-wide Chixculub asteroid impact crater in Mexico suggested a sudden extinction of dinosaurs and other species, driven by the impact. But others have argued that a long, slow decline in dinosaur diversity contributed to their extinction.

Piecing together the story is hard. It’s not just that dinosaur fossils are so rare; the fossil record is also patchy.

Most of what we know about the dinosaurs’ final days is the result of intensive study of a few places in the United States, Canada and Mongolia. Far less is known about dinosaurs of the southern landmasses – South America, India, Madagascar, Australia, Antarctica, New Zealand.

Partly that’s down to geography; it’s hard to find dinosaurs in rainforests. Partly there have, historically, just been more palaeontologists and museums in the northern hemisphere. The question is whether the picture is biased.

Because it’s such a huge landmass, Africa probably had far more dinosaur species than North America. Yet until recently we’ve known hardly anything about Africa’s end-Cretaceous dinosaurs. Africa has few terrestrial rocks from this period. That’s because high levels of volcanic activity pushed sea levels up, submerging much of Africa under shallow seas. Dinosaurs, being terrestrial, rarely occur in marine rocks. But rarely doesn’t mean never. Study enough marine fossils, you eventually find a dinosaur.

And in Morocco, we’ve studied lots of marine fossils.

What we’ve found

The phosphate deposits of Morocco are the remains of an ancient seabed, dating to the final million years of the dinosaur era. They’re full of fish bones and scales, shark teeth and marine reptiles. Vast numbers of marine reptiles – mosasaurs, plesiosaurs, sea turtles.

But once in a while, dinosaurs turn up.

It’s not clear how dinosaur bones ended up in marine sediments. Dinosaurs may have swum out to islands searching for food, as deer and elephants do today, and some might have drowned. Other dinosaurs might have been washed out to sea by floods or storms, or drowned in rivers that carried them downstream to the ocean. Still others may have died on the shoreline before being carried out on a high tide. But some improbable series of events transported dinosaurs into the ocean.

The dinosaurs of the late Maastrichtian of Morocco. By Nick Longrich.

And so, studying marine beds, and working over many years, we’ve slowly put together a picture of Africa’s last dinosaurs, bone by bone.

Africa’s last dinosaurs included titanosaurian sauropods, long-necked plant-eaters the size of elephants. Horse-sized duckbill dinosaurs filled the herbivore niche. But the carnivores are particularly interesting. Sitting at the top of the food chain, they tell us a lot about the ecosystem. And African predatory dinosaurs were diverse, implying diverse herbivores, and lots of them.

The African duckbill dinosaur, Ajnabia odysseus. By Raul Martin.

The top predator was a ten-metre-long animal called Chenanisaurus barbaricus. So far Chenanisaurus is known from just a jawbone, but this tells us it was part of the Abelisauridae, a bizarre family of carnivores found in South America, India, Madagascar and Europe, while tyrannosaurs dominated in the north. Abelisaurs had short, bulldog snouts, and sometimes horns, and they had bizarre, stumpy little arms that make the arms of T. rex look massive by comparison.

Now, fossils of two new abelisaurs have appeared in Morocco.

One is known from a tibia, a shin bone. It was smaller than Chenanisaurus, about five metres long – small by dinosaur standards, but large compared to modern predators. Curiously, it resembles abelisaurs found in South America. It’s possible this marks an ancient land connection that existed between the continents 100 million years ago. Or, abelisaurs may have swum the narrow seaway separating the continents.

Tibia of a new abelisaurid from Sidi Chennane, in Morocco. Nick Longrich.

Another bone is from the foot of an even smaller abelisaurid, just three metres long. Similar small abelisaurids occur in Europe; it may be related to them.

In recent months, more dinosaur fossils and more species have turned up. We’re still writing these fossils up, so we can’t say much now, but finding so many species in a handful of fossils tells us we’re sampling from a highly diverse fauna.

While fossils from the Great Plains in North America may record a decline in dinosaur diversity, this may be a local phenomenon, not a global one. It’s possible global cooling in the latest Cretaceous hit higher-latitude environments hard, reducing diversity. But the African dinosaur fauna hints that at low latitudes, dinosaurs were thriving, even diversifying. If so, that means dinosaurs were cut down in their prime; burning out rather than fading away.

Foot bone of a small abelisaurid from Sidi Daoui, Morocco. Nick Longr.

What our findings show

Africa’s last dinosaurs, especially its diverse predatory dinosaurs, suggest that immediately before their extinction, the dinosaurs thrived.

For over 100 million years, they evolved and diversified, producing a remarkable range of species: predators, herbivores, aquatic species, even flying forms, the birds. Then in a single, catastrophic moment, everything was wiped out in the months of darkness caused by dust and soot from the impact. Everything, except a half-dozen or so bird species.

Evolution is driven by rare, improbable events like asteroid impacts. Curiously, science is often driven forward by improbable events as well – like the unlikely discovery of dinosaurs buried millions of years ago, at the bottom of the sea.

 

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Here’s how Helene and other storms dumped a whopping 40 trillion gallons of rain on the South

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More than 40 trillion gallons of rain drenched the Southeast United States in the last week from Hurricane Helene and a run-of-the-mill rainstorm that sloshed in ahead of it — an unheard of amount of water that has stunned experts.

That’s enough to fill the Dallas Cowboys’ stadium 51,000 times, or Lake Tahoe just once. If it was concentrated just on the state of North Carolina that much water would be 3.5 feet deep (more than 1 meter). It’s enough to fill more than 60 million Olympic-size swimming pools.

“That’s an astronomical amount of precipitation,” said Ed Clark, head of the National Oceanic and Atmospheric Administration’s National Water Center in Tuscaloosa, Alabama. “I have not seen something in my 25 years of working at the weather service that is this geographically large of an extent and the sheer volume of water that fell from the sky.”

The flood damage from the rain is apocalyptic, meteorologists said. More than 100 people are dead, according to officials.

Private meteorologist Ryan Maue, a former NOAA chief scientist, calculated the amount of rain, using precipitation measurements made in 2.5-mile-by-2.5 mile grids as measured by satellites and ground observations. He came up with 40 trillion gallons through Sunday for the eastern United States, with 20 trillion gallons of that hitting just Georgia, Tennessee, the Carolinas and Florida from Hurricane Helene.

Clark did the calculations independently and said the 40 trillion gallon figure (151 trillion liters) is about right and, if anything, conservative. Maue said maybe 1 to 2 trillion more gallons of rain had fallen, much if it in Virginia, since his calculations.

Clark, who spends much of his work on issues of shrinking western water supplies, said to put the amount of rain in perspective, it’s more than twice the combined amount of water stored by two key Colorado River basin reservoirs: Lake Powell and Lake Mead.

Several meteorologists said this was a combination of two, maybe three storm systems. Before Helene struck, rain had fallen heavily for days because a low pressure system had “cut off” from the jet stream — which moves weather systems along west to east — and stalled over the Southeast. That funneled plenty of warm water from the Gulf of Mexico. And a storm that fell just short of named status parked along North Carolina’s Atlantic coast, dumping as much as 20 inches of rain, said North Carolina state climatologist Kathie Dello.

Then add Helene, one of the largest storms in the last couple decades and one that held plenty of rain because it was young and moved fast before it hit the Appalachians, said University of Albany hurricane expert Kristen Corbosiero.

“It was not just a perfect storm, but it was a combination of multiple storms that that led to the enormous amount of rain,” Maue said. “That collected at high elevation, we’re talking 3,000 to 6000 feet. And when you drop trillions of gallons on a mountain, that has to go down.”

The fact that these storms hit the mountains made everything worse, and not just because of runoff. The interaction between the mountains and the storm systems wrings more moisture out of the air, Clark, Maue and Corbosiero said.

North Carolina weather officials said their top measurement total was 31.33 inches in the tiny town of Busick. Mount Mitchell also got more than 2 feet of rainfall.

Before 2017’s Hurricane Harvey, “I said to our colleagues, you know, I never thought in my career that we would measure rainfall in feet,” Clark said. “And after Harvey, Florence, the more isolated events in eastern Kentucky, portions of South Dakota. We’re seeing events year in and year out where we are measuring rainfall in feet.”

Storms are getting wetter as the climate change s, said Corbosiero and Dello. A basic law of physics says the air holds nearly 4% more moisture for every degree Fahrenheit warmer (7% for every degree Celsius) and the world has warmed more than 2 degrees (1.2 degrees Celsius) since pre-industrial times.

Corbosiero said meteorologists are vigorously debating how much of Helene is due to worsening climate change and how much is random.

For Dello, the “fingerprints of climate change” were clear.

“We’ve seen tropical storm impacts in western North Carolina. But these storms are wetter and these storms are warmer. And there would have been a time when a tropical storm would have been heading toward North Carolina and would have caused some rain and some damage, but not apocalyptic destruction. ”

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Follow AP’s climate coverage at https://apnews.com/hub/climate

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Follow Seth Borenstein on Twitter at @borenbears

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Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.

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‘Big Sam’: Paleontologists unearth giant skull of Pachyrhinosaurus in Alberta

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It’s a dinosaur that roamed Alberta’s badlands more than 70 million years ago, sporting a big, bumpy, bony head the size of a baby elephant.

On Wednesday, paleontologists near Grande Prairie pulled its 272-kilogram skull from the ground.

They call it “Big Sam.”

The adult Pachyrhinosaurus is the second plant-eating dinosaur to be unearthed from a dense bonebed belonging to a herd that died together on the edge of a valley that now sits 450 kilometres northwest of Edmonton.

It didn’t die alone.

“We have hundreds of juvenile bones in the bonebed, so we know that there are many babies and some adults among all of the big adults,” Emily Bamforth, a paleontologist with the nearby Philip J. Currie Dinosaur Museum, said in an interview on the way to the dig site.

She described the horned Pachyrhinosaurus as “the smaller, older cousin of the triceratops.”

“This species of dinosaur is endemic to the Grand Prairie area, so it’s found here and nowhere else in the world. They are … kind of about the size of an Indian elephant and a rhino,” she added.

The head alone, she said, is about the size of a baby elephant.

The discovery was a long time coming.

The bonebed was first discovered by a high school teacher out for a walk about 50 years ago. It took the teacher a decade to get anyone from southern Alberta to come to take a look.

“At the time, sort of in the ’70s and ’80s, paleontology in northern Alberta was virtually unknown,” said Bamforth.

When paleontogists eventually got to the site, Bamforth said, they learned “it’s actually one of the densest dinosaur bonebeds in North America.”

“It contains about 100 to 300 bones per square metre,” she said.

Paleontologists have been at the site sporadically ever since, combing through bones belonging to turtles, dinosaurs and lizards. Sixteen years ago, they discovered a large skull of an approximately 30-year-old Pachyrhinosaurus, which is now at the museum.

About a year ago, they found the second adult: Big Sam.

Bamforth said both dinosaurs are believed to have been the elders in the herd.

“Their distinguishing feature is that, instead of having a horn on their nose like a triceratops, they had this big, bony bump called a boss. And they have big, bony bumps over their eyes as well,” she said.

“It makes them look a little strange. It’s the one dinosaur that if you find it, it’s the only possible thing it can be.”

The genders of the two adults are unknown.

Bamforth said the extraction was difficult because Big Sam was intertwined in a cluster of about 300 other bones.

The skull was found upside down, “as if the animal was lying on its back,” but was well preserved, she said.

She said the excavation process involved putting plaster on the skull and wooden planks around if for stability. From there, it was lifted out — very carefully — with a crane, and was to be shipped on a trolley to the museum for study.

“I have extracted skulls in the past. This is probably the biggest one I’ve ever done though,” said Bamforth.

“It’s pretty exciting.”

This report by The Canadian Press was first published Sept. 25, 2024.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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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.”

The Canadian Press. All rights reserved.

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