Exploring Prehistoric Toronto
Sorry for my prolonged absence -- I've been a very busy Museum Girl in the Peru Dig, and then with ROMKids. I've been instructing Summer Club this year, which got started earlier in the summer with Ecoquest, and I'm currently finishing off with Science Frontiers.
I've got a great group this year, and one of my favourite days so far was my traditional Science-course field trip to look for fossils along the Humber River.
About 440 million years ago, Toronto was located somewhere near the equator, and was at the bottom of a saltwater sea. In certain places, like the Don Valley Brickworks and along the Humber River, you can find tons of sedimentary rocks (rocks that were formed by sediment piling up in layers), and trapped in that sediment are thousands of fossils of prehistoric sea creatures. Things like shells of clams, crinoids (which are related to starfish), bryozoans (which look a bit like branching coral), and nautiloid cephalopods -- creatures related to squids, which are like modern nautiluses, but with straight shells instead of curled ones. Nautiloids were the sharks of the ancient oceans.
The best one I've seen was last year, when Matthew found an amazing nautiloid:
This is an amazing fossil, and one of my favourites.
But this year's hunt was pretty good, too. Here's this year's big nautiloid find (we think):
And my favourite find of this year was a star-shaped crinoid. Because crinoids are related to starfish, they share the same five-part body plan. I've found tons of crinoids with round centres (the cross-sections look like the rock is full of tiny Life Savers), but this is the first year I've ever seen a star-shaped cross section. You can see it really well here, next to the branching bryozoan:
There's all kinds of history right in your own backyard. Get out there and explore it!
I've got a great group this year, and one of my favourite days so far was my traditional Science-course field trip to look for fossils along the Humber River.
About 440 million years ago, Toronto was located somewhere near the equator, and was at the bottom of a saltwater sea. In certain places, like the Don Valley Brickworks and along the Humber River, you can find tons of sedimentary rocks (rocks that were formed by sediment piling up in layers), and trapped in that sediment are thousands of fossils of prehistoric sea creatures. Things like shells of clams, crinoids (which are related to starfish), bryozoans (which look a bit like branching coral), and nautiloid cephalopods -- creatures related to squids, which are like modern nautiluses, but with straight shells instead of curled ones. Nautiloids were the sharks of the ancient oceans.
The best one I've seen was last year, when Matthew found an amazing nautiloid:
This is an amazing fossil, and one of my favourites.
But this year's hunt was pretty good, too. Here's this year's big nautiloid find (we think):
And my favourite find of this year was a star-shaped crinoid. Because crinoids are related to starfish, they share the same five-part body plan. I've found tons of crinoids with round centres (the cross-sections look like the rock is full of tiny Life Savers), but this is the first year I've ever seen a star-shaped cross section. You can see it really well here, next to the branching bryozoan:
There's all kinds of history right in your own backyard. Get out there and explore it!