A mistaken fossil rewrites the history of the Indian subcontinent for the second time

A mistaken fossil rewrites the history of the Indian subcontinent for the second time

What at first looked like a Dickinsonia fossil (left) had decayed and started peeling off the rock in just a few years (right), a sign that it was something much more modern. Credit: Gregory Retallack/Joe Meert

In 2020, amid the first pandemic lockdowns, a planned scientific conference in India never took place.

But a group of geologists who were already there decided to make the most of their time and visited the Bhimbetka Rock Shelters, a series of caves with ancient rock art near Bhopal, India. There they spotted the fossil Dickinsonia¸ a flat, elongated, primitive animal from before the evolution of complex animals. This is the very first discovery of Dickinsonia in India.

The animal lived 550 million years ago, and the discovery seemed to settle once and for all the surprisingly controversial age of the rocks that make up much of the Indian subcontinent. The discovery caught the attention of The New York Times, The Weather Channel and the newspaper Nature as well as many Indian newspapers.

Only, it turns out that the “fossil” was a case of mistaken identity. The real culprit? The bees.

Researchers from the University of Florida visited the site last year and found that the object had apparently decayed considerably, which is quite unusual for a fossil. Additionally, giant bee nests populate the site, and the mark scientists spotted in 2020 looked a lot like the remains of those large hives.

A mistaken fossil rewrites the history of the Indian subcontinent for the second time

The caves near Bhopal, India are home to prehistoric rock art. Because they have no fossils, they are difficult to date. Credit: Joseph Meert

“As soon as I looked at it, I thought something was wrong here,” said Joseph Meert, a UF geology professor and geology expert in the area. “The fossil was peeling off the rock.”

The ancient fossil also lay almost vertically along the walls of the caves, which made no sense. Instead, Meert says, fossils from this area should only be visible flat on the floor or ceiling of cave structures.

Meert collaborated on the investigation with his graduate students Samuel Kwafo and Ananya Singha and Professor Manoj Pandit from the University of Rajasthan. They documented the object’s rapid decay and photographed similar remains from nearby beehives. The team published their findings on the mistaken identity on January 19 in the newspaper Gondwana Researchwho previously published the report of the chance discovery of Dickinsonia fossils.

Gregory Retallack, professor emeritus at the University of Oregon and lead author of the original paper, says he and his co-authors agree with Meert’s conclusions that the object is actually just ‘a hive. They submit a comment in support of the new article to the journal.

This type of self-correction is a fundamental tenet of the scientific method. But the reality is that it’s hard for scientists to admit mistakes, and that doesn’t happen often.

A mistaken fossil rewrites the history of the Indian subcontinent for the second time

Large hives dot the site. After being abandoned and decaying, they briefly resemble fossils of the primitive animal Dickinsonia. Credit: Joseph Meert

“It’s rare but essential that scientists confess their mistakes when new evidence is uncovered,” Retallack said in an email.

The correction of the fossil record calls into question the age of the rocks. Since the rock formation contains no fossils from any known period, it can be difficult to date it.

Meert says evidence continues to show the rocks are over a billion years old. His team used the radioactive decay of tiny crystals called zircons to date the rocks to this period. And the magnetic signature of rocks, which captures information about the Earth’s magnetic field when the rocks formed, closely matches signatures of formations dated with certainty to a billion years ago.

Other scientists have reported findings supporting a younger age. The period is essential to understand because of its implications for the evolution of life in the region and the formation of the Indian subcontinent.

“You might say, ‘Okay, well, what’s the deal if they’re 550 million or a billion years old?’ Well, there are a lot of implications,” Meert said. “One has to do with the paleogeography of the time, what was happening to the continents, where the continents were, how they came together. And that was a time when life was going through a major shift from very simple fossils to more complex fossils. fossils.”

“So trying to understand the paleogeography at the time is very, very important. And to understand the paleogeography, we need to know the age of the rocks,” he said.

More information:
Joseph G. Meert et al, Stinging News: ‘Dickinsonia’ discovered in India’s Upper Vindhyan not worth the buzz, Gondwana Research (2023). DOI: 10.1016/j.gr.2023.01.003

Provided by the University of Florida

Quote: Mistaken fossil rewrites the history of the Indian subcontinent for the second time (February 1, 2023) Retrieved February 2, 2023 from https://phys.org/news/2023-02-mistaken-fossil-rewrites-history- indian.html

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