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

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

But a group of geologists already on the ground 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 saw the fossil of Dickinsonia, a flat, elongated, primitive animal that predated the evolution of complex animals. It marked the first discovery of Dickinsonia in India.

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

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

Researchers from the University of Florida traveled to the site last year and found that the object had apparently decayed significantly, quite unusual for a fossil. Additionally, giant bee nests populate the site, and the mark detected by scientists in 2020 closely resembled the remains of these large hives.

“As soon as I looked at it, I thought something wasn’t right here,” said Joseph Meert, a UF professor of geology and an expert on the geology of the area. “The fossil was peeling off the rock.”

The ancient fossil also lay nearly vertical along the cave walls, which made no sense. Instead, Meert says, fossils in this area should only be visible on the floor or ceiling of cave structures.

Meert collaborated on the research with her graduate students Samuel Kwafo and Ananya Singha and University of Rajasthan professor Manoj Pandit. They documented the rapid decomposition of the object and photographed similar remains from nearby hives. The team published their findings on the mistaken identity on January 19 in the journal Gondwana researchwho previously published the report of the Dickinsonia fossil find serendipity.

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 findings that the object is really just a beehive. They are submitting a comment in support of the new article to the magazine.

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

“It is rare but essential for scientists to confess errors when new evidence is discovered,” Retallack said in an email.

correcting the fossil record brings into question the age of the rocks again. Because the rock formation does not have any fossils from a known time period, dating it can be difficult.

Meert says the evidence continues to point to the rocks being more than a billion years old. His team has used the radioactive decay of tiny crystals called zircons to date the rocks to that time period. And the magnetic signature of the rocks, which captures information about Earth’s magnetic field when the rocks formed, closely matches signatures of formations confidently dated a billion years ago.

Other scientists have reported findings supporting a younger age. Understanding the time period is essential because of its implications for the evolution of life in the area and how the Indian subcontinent formed.

“You could say, ‘Okay, well, what’s the problem 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 with the continents, where the continents were located, how they were assembled. And it was a period when life was going through a major change, from very simple fossils to more complex ones. fossils”.

“So trying to figure out the paleogeography at that time is very, very important. And to figure out the paleogeography, we have to know the age of the rocks,” he said.