Fossil ‘mother lode’ records Earth-shaking asteroid’s impact, says study

Published March 31, 2019
This photo taken and handout on March 29, 2019 by the University of Kansas, shows Robert DePalma (L) and field assistant Kylie Ruble (R)  excavate fossil carcasses from the Tanis deposit. ─ AFP
This photo taken and handout on March 29, 2019 by the University of Kansas, shows Robert DePalma (L) and field assistant Kylie Ruble (R) excavate fossil carcasses from the Tanis deposit. ─ AFP

WASHINGTON: Scientists in the US say they have discovered the fossilised remains of a mass of creatures that died minutes after a huge asteroid slammed into the Earth 66 million years ago, sealing the fate of the dinosaurs.

In a paper to be published on Monday, a team of paleontologists headquartered at the University of Kansas say they found a “mother lode of exquisitely preserved animal and fish fossils” in what is now North Dakota.

The asteroid’s impact in what is now Mexico was the most cataclysmic event ever known to befall Earth, eradicating 75 percent of the planet’s animal and plant species, extinguishing the dinosaurs and paving the way for the rise of humans.

A partially exposed, perfectly preserved, 66-million-year-old fish fossil uncovered by Mr. DePalma and his colleagues. ─ AFP
A partially exposed, perfectly preserved, 66-million-year-old fish fossil uncovered by Mr. DePalma and his colleagues. ─ AFP

Researchers believe the impact set off fast-moving, seismic surges that triggered a sudden, massive torrent of water and debris from an arm of an inland sea known as the Western Interior Seaway.

At the Tanis site in North Dakota’s Hell Creek Formation, the surge left “a tangled mass of freshwater fish, terrestrial vertebrates, trees, branches, logs, marine ammonites and other marine creatures,” according to Robert DePalma, the report’s lead author.

Some of the fish fossils were found to have inhaled “ejecta” associated with the Chicxulub event, suggesting seismic surges reached North Dakota within “tens of minutes,” he said.

“The sedimentation happened so quickly everything is preserved in three dimensions — they’re not crushed,” said co-author David Burnham.

A tangled mass of articulated fish fossils uncovered in North Dakota. ─ AFP
A tangled mass of articulated fish fossils uncovered in North Dakota. ─ AFP

“It’s like an avalanche that collapses almost like a liquid, then sets like concrete. They were killed pretty suddenly because of the violence of that water. We have one fish that hit a tree and was broken in half.” The fossils at Tanis include what were believed to be several newly identified fish species, and others that were “the best examples of their kind,” said DePalma, a graduate student and curator of the Palm Beach Museum of Natural History in Florida.

“We look at moment-by-moment records of one of the most notable impact events in Earth’s history. No other site has a record quite like that,” he said.

“And this particular event is tied directly to all of us — to every mammal on Earth, in fact. Because this is essentially where we inherited the planet.

Published in Dawn, March 31st, 2019

Opinion

Editorial

Kurram atrocity
Updated 22 Nov, 2024

Kurram atrocity

It would be a monumental mistake for the state to continue ignoring the violence in Kurram.
Persistent grip
22 Nov, 2024

Persistent grip

An audit of polio funds at federal and provincial levels is sorely needed, with obstacles hindering eradication efforts targeted.
Green transport
22 Nov, 2024

Green transport

THE government has taken a commendable step by announcing a New Energy Vehicle policy aiming to ensure that by 2030,...
Military option
Updated 21 Nov, 2024

Military option

While restoring peace is essential, addressing Balochistan’s socioeconomic deprivation is equally important.
HIV/AIDS disaster
21 Nov, 2024

HIV/AIDS disaster

A TORTUROUS sense of déjà vu is attached to the latest health fiasco at Multan’s Nishtar Hospital. The largest...
Dubious pardon
21 Nov, 2024

Dubious pardon

IT is disturbing how a crime as grave as custodial death has culminated in an out-of-court ‘settlement’. The...