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Ratcliffe Brook Formation


Dr. Sören Jensen, Area de Paleontologia, Facultad de Ciencias, Universidad de Extremadura, Spain

The area of Saint John is one of the classical areas for the understanding of Cambrian. Especially the works by Matthew is now considered a classic, and one of the things he described were trace fossils in a unit now called the Ratcliffe Brook Formation. And here we have an example of this. So this is a sandstone, and in the sandstone we can see this slightly darker band, and that’s the trace of an animal which plowed through the sandy sediment, probably processing the sediment for food material. And as we can see this was quite a large animal. This is Cambrian. This is perhaps about 535 million years and this gives a rough idea about the width of the animal. What it doesn’t really tell us is what kind of animal made it, but comparisons have been made by traces made by slugs. But of course this is so far back in time that it could have been an animal which we have no knowledge today.