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

Smog hazard
Updated 05 Nov, 2024

Smog hazard

The catastrophe unfolding in Lahore is a product of authorities’ repeated failure to recognise environmental impact of rapid urbanisation.
Monetary policy
05 Nov, 2024

Monetary policy

IN an aggressive move, the State Bank on Monday reduced its key policy rate by a hefty 250bps to 15pc. This is the...
Cultural power
05 Nov, 2024

Cultural power

AS vital modes of communication, art and culture have the power to overcome social and international barriers....
Disregarding CCI
Updated 04 Nov, 2024

Disregarding CCI

The failure to regularly convene CCI meetings means that the process of democratic decision-making is falling apart.
Defeating TB
04 Nov, 2024

Defeating TB

CONSIDERING the fact that Pakistan has the fifth highest burden of tuberculosis in the world as per the World Health...
Ceasefire charade
Updated 04 Nov, 2024

Ceasefire charade

The US talks of peace, while simultaneously arming and funding their Israeli allies, are doomed to fail, and are little more than a charade.