It could be called an anti-climax of ancient nature. Two independent groups of scientists—one from India and another from the United States—have found that ‘an iconic fossil of a 550 million-year-old early life form’ found at the world heritage site Bhimbetka, about 50kms from Bhopal, is actually a ‘leftover impression of a fallen/decayed beehive’.
Among the two, the team of Indian scientists led by palaeobiologist Santosh Kumar Pandey of the Birbal Sahni Institute of Palaeosciences, Lucknow, have more conclusively proven that the specimens at Bhimbetka were ‘pseudofossil’ with laboratory tests that confirmed presence of beeswax in the samples of the specimens collected from the spot.
The claim of discovery of the ‘first ever specimen of fossil of Dickinsonia in India’ by prominent palaeontologist Gregory Retallack of the University of Oregon and his team, had created a huge buzz in February 2021 in the scientific world internationally, due to its huge significance in study of ancient landscapes and life forms.
However, after new evidence presented by the two groups of scientists, Retallack and colleagues have accepted their mistake and made it official in the form of a scientific paper. In an email response to The Week, Retallack shared the paper and said “Such admissions (of mistake) are a rare but essential part of scientific progress.”
Pandey told The Week that during field visits to Bhimbetka, he and his team members had an immediate feeling that the purported ‘fossil’ specimens – three leaf-like imprints on the wall near the entrance of auditorium cave (shelter number 3) of Bhimbetka – were impressions of fallen beehives. This was due to the presence of live beehives and similar leftover impressions of decayed/fallen beehives in proximity of the celebrated specimens.
However, for getting conclusive evidence, the team collected samples of the ‘fossil’ in August 2022 after receiving due permission from the Archaeological Survey of India (ASI), which protects the world heritage site, the scientist said.
Scientific tests like Raman Spectroscopy and X-Ray Diffraction (XRD) analyses were conducted on the samples and it proved the presence of beeswax in them. Pandey and associates have published a paper busting the claim of ‘dickinsonia fossil’ in the March 2023 volume of the Journal of Geological Society of India. The paper also mentions other points like inconsistencies in placement, morphology (structure) and rapid ‘decay’ (flaking off) of the purported fossil, to prove it as ‘pseudofossil’.
Pandey and team’s paper mentions in context of placement of the ‘fossil’ that it is ‘not entirely preserved on the bedding plane (as it expected of such fossils); instead it is partially preserved on the bedding plane and in part on the 'transversally cut face of the Maihar Sandstone outcrop'.
Another group of scientists led by Joseph G Meert, professor of Geology with University of Florida, also visited Bhimbetka in December 2022, to look at the ‘fossil’ specimens and they also noticed the presence of beehives and impressions of fallen hives similar to the specimens claimed to be Dickinsonia fossil.
Meert told The Week through email that there are three basic reasons to conclude that the ‘fossil is simply the remnant of a giant beehive’. “The fossil was positioned at an odd angle. Most fossils lie flat along the tops and bottoms of beds. This one was curled. The ‘fossil’ had decayed significantly since 2020 when Retallack first saw it. It seemed strange that a fossil that made it through 550 million years would suddenly decay in the past two years. Also, there were beehives everywhere and my suspicions were raised almost immediately. I think I told my students and colleague Manoj Pandit that I have a suspicion that this is the remains of a beehive,” Meert said.
Meert and team’s research paper on these findings have been published in the May 2023 volume of Gondwana Research – an international scientific journal on earth sciences.
The Week had done a detailed story on the ‘stunning discovery’ in February 2021, raising questions over the rapid ‘flaking off’ of the ‘fossil’. It had also mentioned that international scientists had raised questions whether the Bhimbetka find was indeed ‘Dickinsonia fossil’ and had suggested deeper studies.
Why was ‘Dickinsonia fossil’ find considered significant?
The discovery was considered extremely significant as it gave a conclusive age of at least 550 million years to the Upper (later) Vindhyan rock formations that host the pre-historic sites like Bhimbetka. This is because Dickinsonia is considered one of the most iconic and puzzling fossils of the Ediacaran period that extended from 635 to 541 million years ago.
The age of the Upper Vindhyan rock formations is a continuing topic of raging debate among geological fraternity. Some believe that the rock formation are around 1,000 millions year old, while others believe that it might be younger at around 530-550 million years old.
Retallack had told The Week back in 2021 that the find of ‘Dickinsonia’ in India was also very significant as it confirmed the fact that the Indian sub-continent, along with Australia (where, among other places, Dickinsonia fossil was found), was part of the supercontinent Gondwanaland that was assembling 550 years ago.
‘Finder’ accepts mistake
One of the interesting aspects of the newer developments is that Retellack and team have accepted their mistake and also published a paper in the June 2023 volume of Gondwana Research in response to Meert and team’s paper.
Retallack’s paper says “Although the remains (purported fossil) had all essential morphological details of Dickinsonia elongata, that regularity of form was fortuitous (rather a chance), and we agree that it is indeed a modern bee nest and not an Ediacaran fossil. Especially persuasive evidence is the way the fossil has flaked off the rock surface within a few years, and hexagonal closures now visible in the partly exfoliated remains. True, Dickinsonia is a negative relief on capping beds that could not peel off in this way, and does not have hexagonal closures.”
The paper, however, goes on to say that “although there is no current evidence of Dickinsonia in India, the implications of close biogeographic links with Australia are supported by Ediacaran plate tectonic reconstructions and the recent discovery of other Ediacaran fossils better known in Australia from the Maihar Sandstone of India (the rock at Bhimbetka where the ‘fossil’ was found).
While, accepting that the specimen was an impression of beehive, the authors, however, express difference over the criterion used by Meert and team (as well as Pandey and team) about the supposed Dickinsonia specimen straddling bedding planes to rule them out as fossils, saying that genuine Australian Dickinsonia specimens also straddle bedding planes in particular conditions.