A news article at ScienceCentric.com reports that single-celled protists have left tracks and grooves in the ocean-bottom that resemble fossil grooves or “trail” fossils that are found in some pre-Cambrian strata. Darwinists have asserted that such pre-Cambrian track or trail fossils must have been produced by complex, multicellular, worm-like animals, thus implying that the Cambrian explosion was not really as explosive as the fossil record makes it appear. Actual fossils of the alleged pre-Cambrian worms that supposedly made the trails are yet to be found, but Darwinists have claimed that the track fossils are smoking gun evidence that they existed. The Darwinists’ story is challenged by this new find: if tracks can be produced by single-celled protists, then pre-Cambrian track fossils do not necessarily indicate the presence of multicellular animals. Since these protists are far less complex than the animals with multicellular body plans that explosively appear in the Cambrian period, Darwinists remain stuck — whether they like it or not — with a very explosive Cambrian explosion that isn’t the mere artifact of an imperfect fossil record. As the article states:

The finding is significant, because similar fossil grooves and furrows found from the Precambrian era, as early as 1.8 billion years ago, have always been attributed to early evolving multi-cellular animals. ‘If our giant protists were alive 600 million years ago and the track was fossilised, a palaeontologist unearthing it today would without a shade of doubt attribute it to a kind of large, multi-cellular, bilaterally symmetrical animal,’ said Matz, an assistant professor of integrative biology. ‘We now have to rethink the fossil record.’

[…]

‘We used to think that it takes bilateral symmetry to move in one direction across the seafloor and thereby leave a track,’ said Matz. ‘You have to have a belly and a backside and a front and back end. Now, we show that protists can leave traces of comparable complexity and with a very similar profile.’

With their find, Matz, Frank and their colleagues argue that fossil traces cannot be used alone as evidence that multi-cellular animals were evolving during the Precambrian, slowly setting the stage for the Cambrian explosion. ‘I personally think now that the whole Precambrian may have been exclusively the reign of protists,’ said Matz. ‘Our observations open up this possible way of interpreting the Precambrian fossil record.’

Matz says the appearance of all the animal body plans during the Cambrian explosion might not just be an artefact of the fossil record….

Of course, Dr. Matz still hopes to retain some kind of an evolutionary explanation for the abrupt appearance of complex animal body plans in the Cambrian period. But I think that Stephen Meyer said it best:

An experience-based analysis of the causal powers of various explanatory hypotheses suggests purposive or intelligent design as a causally adequate — and perhaps the most causally adequate — explanation for the origin of the complex specified information required to build the Cambrian animals and the novel forms they represent. For this reason, recent scientific interest in the design hypothesis is unlikely to abate as biologists continue to wrestle with the problem of the origination of biological form and the higher taxa.

(Stephen C. Meyer, The Origin of Biological Information and the Higher Taxonomic Categories, Proceedings of the Biological Society of Washington, Vol. 117(2):213-239 (2004).)