Emily Hughes brings us tales of adventure and discovery from the Australian Outback as she and her mother search for unbelievably ancient fossils. Her team digs up the creatures that form the evolutionary boundary between microorganism and animal—the Ediacaran biota.This pit has both the layers of different rock beds, and the ripples of the seafloor. (Photo by Emily Hughes)
Recently, I spent a few days in Hawaii for the first time. I spent most of that in the ocean wearing fins, mask and a snorkel, watching brightly-colored fish and occasional turtles drift by. As I swam around, I noticed that the diversity of the coral, sponges and other benthos-dwellers was great, and in every new direction I swam, there were different kinds of sea creatures. It was totally awesome.
As I’m sitting on the top of a mountain so I can get a few bars of internet service, the sky is covered in a thick layer of clouds and I’m battling huge gales of wind. My thoughts keep returning to the warm, humid days in Hawaii and the snorkeling that took up many of my hours there.
My wishful thinking about the Hawaiian ocean got me wondering about what snorkeling would have been like here, on this frigid mountain in the Australian Outback, 560-million years ago. Maybe it’s just because I’m cold, but I can only imagine how totally awesome it would have been.
As I mentioned in a previous post, the part of the Australian outback that I’m currently in would have been completely underwater during the Ediacaran Period, 560-million years ago. But would the snorkeling have been any good, or would everything look exactly the same wherever you swam?
Well, it turns out, the snorkeling would have been fantastic. What our team has discovered is that the seafloor was extremely heterogeneous. Though there were no fish, one would have been very happy to have fins so as to swim from one community of organisms on the seafloor to another.
Take one of my favorite fossils, Charnia. This is a kind of frond that was attached to the bottom of the seafloor. They could be huge—up to a meter tall—and would have been awesome to look at as they moved to the undulation of the ocean.
There are also Dickinsonia (an oval-shaped organism) and Spriggina (which looks like an arthropod superficially), two species with segments that lined the ocean floor, as well as tube creatures like Funisia, which lived in dense assemblages and were up to a foot in height off the seafloor. If you were to go scuba-diving in the Ediacaran Period, you would see something of an alien world: Charnia fronds, perhaps strangely colored, and amidst these, small and oddly shaped soft-bodied organisms, many of which are still hard to classify as plant, animal, fungus or even some other long-dead kingdom of life. Hard-shelled body parts hadn’t evolved yet, so bumping into any of these things would probably feel soft and slick.
And, the seafloor would have had beautiful ripples. We find these ripples on our rock beds, and we even decorated one of our walkways with rippled rock so any visitors could experience standing in the middle of the Ediacaran sea. “STC”, the letters on our walkway, stand for South Tennis Courts, the name we’ve given to one of our fossil sites.
One of the most important parts of what we do here is helping people understand how important it is to conserve and take care of these fossils that have told us so much. So, how beautiful the Ediacaran seafloor would have looked or the snorkeling conditions 560-million years ago are not only things that catch my attention, but hopefully yours as well. After all, there is truly nothing like looking at amazing creatures, be it a month ago in Hawaii, or today in the 560-million year fossils preserved in the rippled rock.