1995-Des-layers in Walcott's Quarry

SUMMARY: Desmond Collins, former Curator of Invertebrate Palaeontology at the Royal Ontario Museum and expedition leader, describes the rock layers in Walcott Quarry. (2:11)

Des Collins speaks to camera standing in Walcott's Quarry
DESCRIPTION: Des Collins speaks to camera standing in Walcott's Quarry

"I'm standing on the floor of Walcott's old quarry from 1917 and earlier. So the phyllopod bed is about seven foot six from my feet to about up in here somewhere."

Collins gestures to a layer of rock above his head
DESCRIPTION: Collins gestures to a layer of rock above his head

"The bottom four feet of the phyllopod bed are the most important ones from the point of view of fossils. There are four individual layers that Walcott called the great Eldonia layer. Next, two layers down was the great Canadapsis layer, and then layer 10 was no name, but it was full of a variety of things. And finally, at about my feet, was the great Marrella layer, where most of the unusual soft-bodied forms were found. In the past we've never been able to know exactly where we were because these layers differ a little bit in thickness. But there's nothing distinctive about them to show them from the front. So when Tim Sullivan started drilling in here, as you can see from the drill marks, and then split out this slab showing all these lovely Eldonias."

Collins picks up a large slab of rock and indicates fossil
DESCRIPTION: Collins picks up a large slab of rock and indicates fossil

"You can see a particularly fine specimen here. You can see its jellyfish-shape with the apron, and then this dark ring here is the gut. At the end of the gut you can sometimes see the feeding tentacles. But you can see there's several: there's one here, there's one here, there's one here …"

Collins points to different fossils
DESCRIPTION: Collins points to different fossils

"That there's several on this, what Walcott called the Great Eldonia layer and obviously that's what it was."

Collins on camera
DESCRIPTION: Collins on camera

"Now the great Eldonia layer is also important because it's the only one where Eldonia occurs commonly, they're rare at other levels, and it's only about two inches thick. So it makes a very good marker bed. It's the best marker bed in the phyllopod bed. So having discovered this now, we're now going to mark this along the quarry wall and we're going to measure everything else from this particular level. So Eldonia is doing us a double favour, one providing us with some very nice fossils of an animal which is very rare and very rarely preserved, because of course they're exclusively soft-bodies, and secondly because we can now use it as a local marker bed for our work here."

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