*Edir* Ooops. Had it set to publish PM, not AM.....my bad....

*Insert The Ramones here*

Rock, rock, rock, rock, rock and roll high school! Because that's a rock, it's roundish so it'll (sort of) roll, I'm not high but I could be if I had any pot or knew where to get some, and you're about to be SCHOOLED!

*Slumps back into his chair and chugs a beer, then opens another* I had plans you know. I was going to write this post about some exciting bit of history that is relevant to the fossils I'm going to tell you about today. But no. Like all of our best laid plans, someone threw a monkey wrench into the works. I causally mentioned in passing that todays post would be on rocks. Someone suggested something else.

Now, I like to please my regular readers, but I also wanted to do my Friday fossil post. Having a request like the one I received caused a conundrum. For about one femtosecond. You all forget, I am Otter. I am the smartest man in the world! And if you need proof, just ask me who the smartest man in the world is. I will, of course, tell you it's me. And I should know, right? I mean, I am the smartest man in the world after all.

You see, the request was if I could post some of that petroleum product known as gasoline. And I figured, why not? Petroleum is a fossil fuel, after all. And this is Friday Rocks!

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So, while I can't provide any actual gasoline with this post, I can tell you where it comes from. It comes from oil.

But where did that oil come from? We call crude oil, natural gas and coal fossil fuels because that's exactly what they are. They are the remains of living entities. Take coal, for instance. During the Carboniferous Period, the planet was a gigantic tropical forest. Not quite like the forest you picture in your mind, though. There were trees, sort of. Proto-trees would be closer. What appeared to be trees were mostly tree ferns. That is, ferns that grew so large they began to evolve into trees. And, of course, ferns. In the Carboniferous, if you were a plant, you were most likely a fern.

Well, all these plants died and piled up on the ground. And piled up. And piled up. Over millions of years, all these plants piled up. The lower ones were crushed under extreme weight causing incredible pressures and heat. This pressure and heat transformed the carbon the plants had stored into coal.

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Oil and natural gas were formed in a similar manner. When people think of the ingredients in fossil fuels like oil, we imagine dinosaurs dying and melting into oil. But no. Not even close. It's a fairly safe bet that zero percent of the worlds oils supplies came from the dinosaurs. The dinos were way too recent.

For a couple of billion years, the only life on the planet lived in the oceans. That's because there was nothing on dry land. Not even land. If it wasn't covered by water, it was plain rock. No plants because there was no soil. (soil is also a fossil byproduct. It's made up of eroded rock and decomposed organic materiel.) But in the oceans lived small, single celled algae. This is the same algae that formed the stromatolites I told you about a few weeks ago. Not all of it formed stormatolites though. Most of it didn't, in fact. Most of it floated around the ocean absorbing the energy from the sun and storing it as carbon. (Photosynthesis, yo!) When the algae died, it slowly sank to the sea floor where it piled up.

It would pile up and be mixed with sediments. Over hundreds of millions of years, the algae got deeper, with more weight piled up on it. Heat from the pressure and from the planet it's self started a transformation. Depending on the amount of pressure and heat dictated what it transformed into. Less heat and pressure formed oil. More heat and pressure formed natural gas.

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But it didn't form into the large deposits we have now. It transformed a drop at a time. But over the years, it would seep up and out through cracks in the rock. Plate tectonics would cause earthquakes which would open more passages. Some of this oil and natural gas would seep all the way to the surface. The La Brea Tar Pits are a good example of this. But even a couple of thousand years ago, humans knew these surface deposits of oil could be used for fuel. They were just scarce, so they never had a lot of it.

But not all the oil and gas seeped to the surface. Sometimes it was blocked and it started to pool. Some of these pools grew immense. And that's the oil deposits we have today. many people will say that once the oil is gone, it's gone. That's not entirely true. New oil is being created all the time. Now, it's not being created at anywhere near the rate we need to make it sustainable, but every year, an extra few barrels of oil are appearing somewhere under ground.

Let me guess....that was more information about oil than you ever cared to know.

You like the rock I have pictured? It's an example of a Cambropallas telesto. It might be hard to see details, but it is also a trilobite. In fact, it's the largest one I have. It is from Morocco, and was originally found as a nodule. That means when it was found, it was extracted as a single rock. That rock was then split in half, and the trilobite was exposed. This results in a positive and a negative. I have both halves, of course.

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Mine is about 7 1/2 inches long, which is about two inches shorter than the largest specimen found. But it's about the average size for one of these. Many collectors like these for the same reason I do; Their size. They might not have the sharpest details, but they are large and make for great display pieces. (the coin is a US quarter, for scale)

But you have to be very careful when buying trilobites like these. They are one of the most counterfeited types out there. So many people want them, a forger will make them by the scores to generate a quick profit. Examples of these types of trilobites are best purchased through a known and reputable dealer.

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This trilobite was a bottom dweller. Most trilobites were, though. They spent their time walking on the sea floor, eating whatever they could. Some trilobites did swim, suspended above the bottom, but the body design of the little bugs made that difficult. Because of the way they were designed, most of the underside of the trilobite was unprotected. This is why they would enroll for protection. There was a small piece of exoskeleton on the underside, though. This was a protective plate that covered the mouth and stomach called the hypostome. I do have examples of trilobites that still have their hypostome attached, but on this one, if it's still attached, it's buried underneath and I'm not digging in the rock....

The hypostome served to protect the mouth and digestive tract, but it was also used by the trilobite to rest the food on as it would grind it up to be eaten. The hypostome was connected to the rest of the exoskeleton at the front, so the trilobite would use it's front legs to push it's food up onto the shelf formed by the hypostome, where it would process it for eating.

And with that, I'll wrap up todays lesson. Well, not really a lesson. More of an informative indulgence on my part. Whatever you want to call it, it's over for today. Have a good weekend, (I won't), and I'll be back Monday with something made up or true.