Terrestrial paleontology jokes
Tuesday, November 11th, 2008 09:44 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
tsaikoA couple of weeks ago when I posted about sabertooth cats hunting in packs, I also mentioned two other jokes from my terrestrial paleontology class. Since a retelling of these jokes has been requested, I will not provide an explanation.
Some people know that even atomic clocks have to be reset every so many years otherwise they get "off" by something less than a second. What people don't realize is that this is because slowly, the day is getting longer as the rotation of the earth gets slower. Taking this to it's logical conclusion, you realize that if the rotation of the earth is getting slower then in the past it must have been faster. Go back enough years (we're talking millions of years here), and you could actually tell a difference.
When the earth was first formed, one rotation took approximately 6 hours. This means that one earth day was six hours long. When blue-green aglae was making stromatolites about 1200 million years ago, the days was a whopping 14.2 hours long. By the time things with bony parts and backbones show up around 500 million years ago, the earth was up to a much more reasonable 21.3 hours in a day. By the time we get to the Permian, right before the big dinosaur explosion of the Triassic, the day is a whopping 22.4 hours long.
Which inspired someone in my class to commit "Can you imagine the dimetrodons walking around going 'Man... if I only had 23 hours in a day I could get all my hunting done.'"
Note: All measurements of the lengths of the day were taken from this rather interesting physics article about *gasp* the length of the day through time.
The end of the Cretaceous was not a good time to be alive. Sure the world was warmer, CO2 and O2 levels were higher, and flowering plants were really beginning to take off after years of domination by ferns and gymnosperms. To help them out, bees had finally make an appearance. Ants, termites, aphids and grasshoppers all show up as well. In the Cretaceous there are lizards and snakes and frogs. Crocodiles and turtles are practically an ancient lineage by now. Birds have taken to the air and the sea. There are mammals around, but they looks like rats or maybe shrews: definitely nothing to write home about.
And lets not forget that a metric fuckton of animals you don't see around now. Dinosaurs are the biggie, but you also have marine reptiles such as ichthyosaurs, mosasaurs, and plesiosaurs. Pterodons were still around, though being edged out by the birds. You had dinosaurs as far north as Greenland and Alaska, and the southern Cretaceous pole had jungles.
All that's nice, but it was about to go to hell in a handbasket. Because at the end of the Cretaceous, 65.5 million years ago, you have one of the most famous mass extinctions to occur. Not the biggest (that's already happened by this point, a mass extinction at the end of the Permian that makes this event look like a pleasant Sunday stroll), but the most famous.
Imagine you are a turtle swimming happily on a warm ocean. You look up at the sky. And suddenly, all you can say is "Oh shit."
Why?
Because something from outer space is about to produce a really big boom when it hits the earth. The end of the Cretaceous is marked by a large bolide impact. That's bad enough, but this impact also happened at quite possibly the absolute worse place ever. It hit in shallow, warm seas with large carbonate deposits quite possibly at a low angle.
What does this mean? Well first, when something that big and at that high a speed enters the atmosphere, it gets really hot. It punches a hole in the atmosphere. Anything it touches is vaporized and ejected upwards. Remember that carbonate? Well, when vaporized it tends to mix with water and cause acid rain. It's all in the atmosphere now, mixing with water and raining back down. That is when it's not causing a giant dust cloud that's blocking the sun or raining down flaming debris and causing world-wide forest fires. Mixed in the the carbonate is quite a lot of sulfur as well. Stronger acid rain for the win! But don't worry folks. Research now suggests the acid rain only happened for about 12 years.
Let's not forget that hole in the atmosphere. With no atmosphere to protect anything, there was a short, intense pulse of radiation which probably cooked a fair number of critters. Remember that low angle I talked about? Most of the super heated rock it flung up and outwards headed towards North America. Good by large chunks of North American flora and fauna.
Since it hit the ocean, there are tsunamis. You can actually still see some of the tsunami deposits from this time period today in Texas and Arkansas. With all the heat from the impact, there's a theory that you had hypercanes: huge, super charged hurricanes that battered the coastlines. And this is only the effects of the impact that we know about. There could be more that we haven't discovered.
You shouldn't be wondering why the dinosaurs died off. You should be wondering how anything managed to survive. Just remember kids, this is not the biggest extinction event we have on record.
Makes you just the slightest bit paranoid doesn't it? XD
Some people know that even atomic clocks have to be reset every so many years otherwise they get "off" by something less than a second. What people don't realize is that this is because slowly, the day is getting longer as the rotation of the earth gets slower. Taking this to it's logical conclusion, you realize that if the rotation of the earth is getting slower then in the past it must have been faster. Go back enough years (we're talking millions of years here), and you could actually tell a difference.
When the earth was first formed, one rotation took approximately 6 hours. This means that one earth day was six hours long. When blue-green aglae was making stromatolites about 1200 million years ago, the days was a whopping 14.2 hours long. By the time things with bony parts and backbones show up around 500 million years ago, the earth was up to a much more reasonable 21.3 hours in a day. By the time we get to the Permian, right before the big dinosaur explosion of the Triassic, the day is a whopping 22.4 hours long.
Which inspired someone in my class to commit "Can you imagine the dimetrodons walking around going 'Man... if I only had 23 hours in a day I could get all my hunting done.'"
Note: All measurements of the lengths of the day were taken from this rather interesting physics article about *gasp* the length of the day through time.
The end of the Cretaceous was not a good time to be alive. Sure the world was warmer, CO2 and O2 levels were higher, and flowering plants were really beginning to take off after years of domination by ferns and gymnosperms. To help them out, bees had finally make an appearance. Ants, termites, aphids and grasshoppers all show up as well. In the Cretaceous there are lizards and snakes and frogs. Crocodiles and turtles are practically an ancient lineage by now. Birds have taken to the air and the sea. There are mammals around, but they looks like rats or maybe shrews: definitely nothing to write home about.
And lets not forget that a metric fuckton of animals you don't see around now. Dinosaurs are the biggie, but you also have marine reptiles such as ichthyosaurs, mosasaurs, and plesiosaurs. Pterodons were still around, though being edged out by the birds. You had dinosaurs as far north as Greenland and Alaska, and the southern Cretaceous pole had jungles.
All that's nice, but it was about to go to hell in a handbasket. Because at the end of the Cretaceous, 65.5 million years ago, you have one of the most famous mass extinctions to occur. Not the biggest (that's already happened by this point, a mass extinction at the end of the Permian that makes this event look like a pleasant Sunday stroll), but the most famous.
Imagine you are a turtle swimming happily on a warm ocean. You look up at the sky. And suddenly, all you can say is "Oh shit."
Why?
Because something from outer space is about to produce a really big boom when it hits the earth. The end of the Cretaceous is marked by a large bolide impact. That's bad enough, but this impact also happened at quite possibly the absolute worse place ever. It hit in shallow, warm seas with large carbonate deposits quite possibly at a low angle.
What does this mean? Well first, when something that big and at that high a speed enters the atmosphere, it gets really hot. It punches a hole in the atmosphere. Anything it touches is vaporized and ejected upwards. Remember that carbonate? Well, when vaporized it tends to mix with water and cause acid rain. It's all in the atmosphere now, mixing with water and raining back down. That is when it's not causing a giant dust cloud that's blocking the sun or raining down flaming debris and causing world-wide forest fires. Mixed in the the carbonate is quite a lot of sulfur as well. Stronger acid rain for the win! But don't worry folks. Research now suggests the acid rain only happened for about 12 years.
Let's not forget that hole in the atmosphere. With no atmosphere to protect anything, there was a short, intense pulse of radiation which probably cooked a fair number of critters. Remember that low angle I talked about? Most of the super heated rock it flung up and outwards headed towards North America. Good by large chunks of North American flora and fauna.
Since it hit the ocean, there are tsunamis. You can actually still see some of the tsunami deposits from this time period today in Texas and Arkansas. With all the heat from the impact, there's a theory that you had hypercanes: huge, super charged hurricanes that battered the coastlines. And this is only the effects of the impact that we know about. There could be more that we haven't discovered.
You shouldn't be wondering why the dinosaurs died off. You should be wondering how anything managed to survive. Just remember kids, this is not the biggest extinction event we have on record.
Makes you just the slightest bit paranoid doesn't it? XD
(no subject)
Date: 11/11/08 05:55 pm (UTC)What other kind is there?
Did you pass up the chance to study Klingon fossils?
(no subject)
Date: 11/11/08 06:00 pm (UTC)(no subject)
Date: 11/11/08 06:18 pm (UTC)I would love to study Klingon fossils. It would be awesome.