As part of my Ph.D. studies I had the pleasure of working on the Ediacaran  Lonymyndian Successions of the Welsh Borderlands, eventually crossing paths with the wonderful Pete Crimes, who ended up being the external examiner of my thesis and then a great friend.  Pete and I published (with one of his former students J. Pauley) on a number of peculiar structures that we collectively called "blobs", but which included morphologies like "donuts", "cherry buns" and "blobs" of various sizes, and the Precambrian pseudofossil Arumberia.

McIlroy, D., Crimes, T. P., and Pauley, J. C. 2005. Fossils and matgrounds from the Neoproterozoic Longmyndian Supergroup, Shropshire, UK. Geological Magazine, 142: 441–455.

I thought that that would be the end of the matter. I knew that the sedimentology could use a modern sequence stratigraphic approach, but my move to Canada seemed to put an end to my Longmyndian interest.  That is until Rich Callow (a student of my Ph.D. supervisor Martin Brasier and currently a postdoc with me here at MUN) discovered microbial filaments in the same successions.

Callow, R. H. T. and Brasier, M. D. 2009. A solution to Darwin’s dilemma of 1859: Exceptional preservation in Salter’s material from the late Ediacaran Longmyndian Supergroup, England. Journal of the Geological Society, London, 166: 1–4.

Rich and I got to talking about the historical material of Salter which is housed in the BGS in Keyworth, UK, and about Longmyndian geology in general. In particular we mused about how amazing it is that the material had not become part of the evolution of life debate in Victorian times, since it was described before Darwin published "On the Origin of Species".  The Longmyndian work was contemporary at a time when it was clear that the abrupt evolution of life, at the base of what we now call the Cambrian Period, was a problem to the theory of Evolution (as Darwin himself admitted).

At about the same time I had become aware of the fantastic Darwin Correspondence Project, in which we found had some correspondence between Darwin and Salter, in a period when Salter was suffering from depression and the breakup of his family.  Looking through correspondence and accounts of interactions with Salter at the time, makes it fairly clear that he was struggling with bipolar disorder.  We suggest that the difficulties that the Victorian upper classes might have experienced in interacting with the unpredictable and volatile side of John Salter brought on  by his mental illness (and perhaps his lower middle class heritage) might have led to to his work being given a less than enthusiastic hearing.

Some 6 years ago now I visited Mistaken Point, one of the most important Ediacaran localities in the world, which sits right at the bottom of the Avalon Peninsula, a couple of hours drive from St. John's.  I was amazed and intrigued by the large and abundant fossils colloquially known as Pizza Disks which do indeed look a little like overloaded 12" deep crust pizzas.  Such structures have long been compared to forms that have been named in the equivalent rocks in the UK (The UK and Eastern Newfoundland once sat on the same terrane known as Avalonia).  These obscure and enigmatic fossils have very little internal detail.  I first came across such forms in the Charnian of Leicestershire, UK as part of my thesis and had never been convinced of them as body fossils, preferring a microbial interpretation for Ivesheadia Blackbrookia and Shepsheadia )

While Pizza discs are rare in the Charnian, they are very abundant in the Ediacaran of the Mistaken Point sections, and are actually some of the very oldest Ediacaran fossils anywhere in the world.  I was bemused as to what they might be.  From casual study of the many specimens I was convinced that a continuum existed between sub-radial assemblages of Fractofusus and  some of the Pizza Discs.  I proposed a model to my colleagues and collaborators from Oxford University.  Martin Brasier (formerly my Ph.D. supervisor- see photo top left) and I set one of our graduate students Alex Liu (now of Cambridge University)  on testing the model that the low fidelity of preservation (which is unlike that seen in many Ediacaran fossils) might be due to microbial communities growing on top of dead and decaying Ediacaran organisms smothering and decaying them.

Alex collected much more field data, and I personally  think has provided substantial data in support of the model.  This work was published in Palaeontology. It took a long time, and is a bit of a departure from the normally ichnological work of the group, but a very worthwhile one.

Liu, A., McIlroy, D. Antcliffe, J. & Brasier, M.D. 2011. Effaced preservation in the Ediacara biota and its implications for the early macrofossil record. Palaeontology, 54, 607-630.

and was also blogged at the Nature Blog

Nikki has just had her first "first author" paper published.  This is a piece of collaborative work that goes back to the days when Rudi Meyer was with us (now at Calgary), and constitutes Allison Moore-Turpin's first paper as well!

Tonkin, N.S., McIlroy, D., Meyer, R. & Moore-Turpin, A. 2010. Bioturbation influence on reservoir quality: A case study from the Cretaceous Ben Nevis Formation, Jeanne d'Arc Basin, offshore Newfoundland, Canada. AAPG Bulletin, 94, 1059-1078.

http://aapgbull.geoscienceworld.org/content/vol94/issue7/