A long story, but basically about the Vindhyan basin
central India. The age of this basin has been controversial since an Indian scientist by the name of Azmi
discovered so called small shelly fossils (SSF's)
from the lower part of the Vindhyan basin in rocks called porcellanites
. The finding is triply odd since (a) porcellanites are volcanic ash beds and unlikely spots for preservation of these types of fossils (b) the age of the lower Vindhyan was thought to be around 1100 Ma at the time and the fossils Azmi claimed to have discovered are Cambrian in age and (c) Azmi was unable to show others where the fossils were discovered.
Since that time, Azmi was vilified for his 'discovery'. Ages obtained from the rock units studied by Azmi are now known to be 1600 million years old (about 1050 million years too old for his 'fossils'). No one has been able to duplicate his findings and experts who looked at his fossils claimed that they were not fossils at all. The younger part of the Vindhyan basin, the so called 'upper vindhyan' contains evidence that it too may be far older than previously thought casting doubts on fossil discoveries in the Upper Vindhyan; however the newer age constraints (made in my lab) are not as concrete as we would like. They are highly suggestive of an older age. In short, life has been hard for Azmi.
Enter paleontologist Stefan Bengtson who has recently published a paper in PNAS regarding 'fossils' in the Lower Vindhyan. Bengtson found fossils similar to those reported by Azmi
, but showed clearly that they are not small shelly fossils or brachiopods, but traces of filamentous algae, bacteria and gas bubbles
Azmi claims he is vindicated, but I'm not so sure this is the case. Azmi continues to insist that the whole of the Vindhyan is 600-500 million years old despite strong evidence to the contrary. The fossil discoveries made by Azmi have not been confirmed and, in fact, the discovery by Bengtson et al. are not brachipods or small shelly fossils. Azmi has demanded a retraction of all criticisms regarding his find, but I'm not so sure that a retraction is needed. Azmi was clearly wrong on many levels and his continued insistence that the Vindhyan is all very young also looks to be wrong. Lastly, no fossils have been found in the porcellanite beds where Azmi claimed to have found SSF's.
Azmi's insistence that he is correct is problematic. At the same time, as Bengtson noted, if Azmi had not been so insistent then it is unlikely that he (Bengtson et al) would have made their discovery. Science moves forward in strange ways.
In my opinion, the paper showed yet again why Azmi's original claims were wrong. We'll have to see if he finally moves towards the consensus on the age of the Vindhyan basins.