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Co-author of extinction study looks ahead

Walter Alvarez and Mark Richards
Geophysicists Walter Alvarez (at left) and Mark Richards (in the background) examine a piece of impact ejecta at the North Dakota fossil site. (Jackson Leibach Photo via University of Kansas)

After days of puzzling over secondhand reports, anyone with an internet connection can now read a research paper about a fossil graveyard in North Dakota that appears to document the day nearly 66 million years ago when an asteroid pushed the dinosaurs and many other species into extinction.

Even scientists who criticized the way the news about the site came out on March 29 acknowledged that the discovery, as described in the Proceedings of the National Academy of Sciences, was astounding.

“I am very much looking forward to the crowd-sourced opinions of everyone,” University of Edinburgh paleontologist Steve Brusatte said in a tweet. “There is a real thrill and a real mystery around this discovery, and it is EXCITING! Let’s see where the evidence leads.”

The study documents fossil evidence for a catastrophic fish kill that did in many other organisms as well. Intermixed with the fossilized remains were tiny beads of glass that had turned to clay. Some of those beads were found embedded in the gills of the fish.

The evidence led the research team, headed by paleontologist Robert DePalma, to conclude that the Cretaceous creatures were washed up onto a sandbar by a giant wave of water. Then they were pelted by hot droplets of molten rock, known as tektites, which were thrown up into the stratosphere by an asteroid impact thousands of miles away.

In the paper, the research team lays out a scenario suggesting that the impact produced a magnitude 10 to 11 earthquake, which sparked a standing wave in the body of water where the fish had lived. Such a wave, known more scientifically as a seiche (pronounced like “saysh”), could have done as much damage as a tsunami within an hour after the asteroid hit. That scenario would leave enough time for the tektites to deliver the coup de grace.

One of the study authors who came up with that scenario is Mark Richards, a geophysicist who left the University of California at Berkeley last July to become the University of Washington’s provost and executive vice president for academic affairs.

Today, Richards said the seiche scenario isn’t the only possibility for explaining what happened in North Dakota during what’s known as the Cretaceous-Paleogene or Cretaceous-Tertiary extinction.

“I think that the surge, unless it was some freak coincidence with something else, was likely seismically induced,” Richards told GeekWire. “Now, it could have been from a seiche. Also, for example, you could have had a local landslide that was triggered by seismic waves. We have to be pretty cautious.”

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‘Antarctic King’ reigned before the dinosaurs

Triassic creatures
Along the banks of a river, three archosaur inhabitants of an Early Triassic forest in Antarctica cross paths: Antarctanax shackletoni sneaks up on an early titanopteran insect, Prolacerta lazes on a log, and an enigmatic large archosaur stalks two unsuspecting dicynodonts known as Lystrosaurus maccaigi. (© Adrienne Stroup, Field Museum)

Tyrannosaurus rex may have reigned as “king of the tyrant lizards” 65 million years ago, but 185 million years before that, a reptile about the size of an iguana was the king of Antarctica.

At least that’s the message contained in the name of a fossil that’s described in a newly published research paper — and is now part of the permanent collection at Seattle’s Burke Museum of Natural History and Culture.

The fossil was collected during an expedition to the frozen continent led by Christian Sidor, who is the museum’s curator of vertebrate paleontology as well as a biology professor at the University of Washington. Sidor and two colleagues, the University of the Witwatersrand’s Roger Smith and Brandon Peecook of Chicago’s Field Museum, laid out the story behind the fossil in a paper published today by the Journal of Vertebrate Paleontology.

Antarctanax shackletoni takes its scientific name from the ancient Greek words for “Antarctic king” and from early-20th-century polar explorer Ernest Shackleton.

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Climate change doom teaches lesson for today

Permian-Triassic extinction
An artist’s conception shows the desolation caused by the Permian-Triassic extinction more than 250 million years ago. (LPI / USRA Illustration)

Scientists say rapidly warming oceans played a key role in the world’s biggest mass extinction, 252 million years ago, and could point to the risks that lie ahead in an era of similarly rapid climate change.

The latest analysis, published in this week’s issue of the journal Science, puts together computer modeling of ancient ocean conditions and a close look at species characteristics to fit new pieces into a longstanding puzzle: What were the factors behind the Permian-Triassic mass extinction, also known as the Great Dying?

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Fossil tells a whale of a tale about evolution

Carlos Peredo with fossils
Carlos Mauricio Peredo, a researcher at the National Museum of Natural History, shows off a 33 million-year-old whale fossil that has been newly classified with the name Maiabalaena nesbittae. (Smithsonian Photo)

A whale that lived 33 million years ago when present-day Oregon was part of the ocean floor has been newly named after a curator at the Burke Museum of Natural History and Culture in Seattle.

And Elizabeth Nesbitt’s whale isn’t your typical cetacean: An analysis of the fossil, published in the Nov. 29 issue of Current Biology, suggests that Maiabalaena nesbittae bridged a gap between species of whales that had teeth and species that have a different mouth-feeding mechanism known as baleen.

“For the first time, we can now pin down the origin of filter-feeding, which is one of the major innovations in whale history,” study co-author Nicholas Pyenson, the National Museum of Natural History’s curator of fossil marine mammals and an affiliate curator at the Burke Museum, said in a news release.

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Fossil hunters unveil Antarctica’s Triassic treasures

Christian Sidor
Christian Sidor, Burke Museum curator of vertebrate paleontology and a biology professor at the University of Washington, recounts the discovery of Triassic fossils. (GeekWire Photo / Alan Boyle)

More than 100 fossil specimens at Seattle’s Burke Museum provide a fresh window into how life thrived in Antarctica about 250 million years ago, thanks to global warming.

The slabs of rock document a time in the early Triassic Era when temperatures got so warm that Earth’s tropics were a virtual “dead zone.” The flip side of that climate equation is that Antarctica, which was still connected to what’s now Africa back then, was temperate enough to support weird sorts of amphibians and other forms of life.

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Burke Museum lifts curtain on T. rex skull

T. rex skull
Burke Museum fossil preparator Bruce Crowley and volunteers Jean Primozich and Ben LeFebvre work on the museum’s T. rex skull. (GeekWire Photo / Alan Boyle)

The only Tyrannosaurus rex skull to go on public display in Washington state is getting its unveiling at Seattle’s Burke Museum of Natural History and Culture – and the best part is that you can watch as more and more of the skull is revealed.

“You can see those teeth coming out,” University of Washington biologist Greg Wilson, the museum’s curator of vertebrate paleontology, told GeekWire today at the big reveal. “And those teeth are gorgeous.”

As he spoke, a team of paleontologists and trained volunteers worked methodically in a glassed-in room, chipping at and brushing away the rock and sand that surrounded the fossil skull.

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Did Homo naledi co-exist with our species?

Homo naledi
This Homo naledi skull is part of a skeleton dubbed “Neo.” (Wits University Photo / John Hawks)

The paleontologists who discovered a previously unknown line of human ancestors in South Africa say that they’ve found more fossils — and that the species, known as Homo naledi, could have lived alongside our own species 250,000 years ago.

The newly disclosed finds from the Rising Star Cave system could reignite the debate over the tangled roots of humanity’s family tree.

Fifty-two scientists from 35 organizations around the world, including University of Washington anthropologist Elen Feuerriegel, were part of the team behind the Rising Star research

In one of the papers published today by the journal eLife, the scientists set the age of the first Homo nadeli fossils they found at between 236,000 and 335,000 years ago, based on radioisotope dating, electron spin resonance dating and an analysis of the flowstone overlying the fossils.

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Scientists spur debate over First Americans

Mastodon unearthed
San Diego Natural History Museum paleontologist Don Swanson points to a rock fragment near a large piece of a mastodon tusk at the excavation site. (San Diego Natural History Museum Photo)

Scientists say the patterns of breakage in mastodon bones found 25 years ago near a San Diego highway suggest that humans battered the beast 130,000 years ago.

That’s a shocker, because before now, the oldest widely accepted evidence of human habitation in North America goes back only about 16,000 years. If the scientists are right, that makes the place they studied, known as the Cerutti Mastodon site, the oldest archaeological site in North America.

“It’s somewhat mind-boggling to have 130,000 years proposed,” said University of Oregon archaeologist Dennis Jenkins. He has found previous evidence for human habitation in 14,000-year-old preserved poop but wasn’t involved in the latest study, published today by the journal Nature.

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Toothy tumor found in 255 million-year-old fossil

Gorgonopsid
Sketch of a gorgonopsian head, in side view. (CCA 3.0 / Dmitry Bogdanov via UW)

A weird type of benign tumor has been discovered in an unlikely place: the fossilized jaw of a distant ancestor of present-day mammals that lived 255 million years ago.

The tumor, known as a compound odontoma, is made up of miniature toothlike structures. It’s not unusual to find such tumors in mammals, including us humans. But it’s unprecedented to find them in the kind of orgonopsid studied by researchers from the University of Washington.

“We think this is by far the oldest known instance of a compound odontoma,” Christian Sidor, a UW professor of biology and curator of vertebrate paleontology at the Burke Museum of Natural History and Culture, said today in a news release.

Sidor is the senior author of a report on the find, published in today’s edition of the Journal of the American Medical Association Oncology. The research could have implications for cancer research as well as for paleontology.

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Mass extinction traced to a ‘one-two punch’

Image: Dying dinosaur
What led to the mass extinction that did in the dinosaurs more than 65 million years ago? Scientists say volcano-caused climate change was a contributing cause. (Credit: Zina Deretsky / NSF)

Scientists generally agree that a catastrophic asteroid blast killed off the dinosaurs and most of Earth’s other species more than 65 million years ago, but newly described evidence supports the view that there was an additional culprit: rapid climate change brought on by volcanic eruptions.

The idea that the Cretaceous-Paleogene mass extinction was a one-two punch isn’t new. For decades, scientists have debated how much the eruptions in the Indian subcontinent’s Deccan Traps contributed to the die-off, as opposed to the miles-wide space rock that hit the coast of Mexico’s Yucatan Peninsula.

A study of ancient Antarctic fossil seashells, published online today in Nature Communications, turns the spotlight on the volcanoes’ effect.

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