33 replies to this topic

[Corax]

kareshi's post about his Spinosaurus tooth in the Show and Tell thread reminded me of how much I love paleontology. For some reason I hate studying biology, but prehistoric animals fascinate me to no end. So this thread is the place to discuss anything pertaining to prehistoric biology and geology (seeing as how those two things are often interrelated).


To start off, I'm really interested at the moment in the Cambrian Explosion. Some interesting theories surrounding its explanation are out there (my favourite is the theory of the evolution of eyes: eyes evolve, completely change predator/prey relationship, then huge evolutionary boom. Very cool) but there's so little evidence it's extremely difficult to be conclusive.

[Corax]

Eurypterids (sea scorpions) are an extinct group of arthropods related to arachnids, which include the largest known arthropods that ever lived.

http://en.wikipedia....wiki/Eurypterid
http://en.wikipedia....wiki/Pterygotus


These things are unbelievable. This reinforces my plan that, when inexplicably teleported eons into the past, I will NEVER go near water of any kind.

[Happy Rectangle]

Eurypterids (sea scorpions) are an extinct group of arthropods related to arachnids, which include the largest known arthropods that ever lived.

http://en.wikipedia....wiki/Eurypterid
http://en.wikipedia....wiki/Pterygotus


These things are unbelievable. This reinforces my plan that, when inexplicably teleported eons into the past, I will NEVER go near water of any kind.

I read somewhere that the first amphibians were prey for the huge flying insects of the time (instead of the other way around). There used to be dragonflies with two-foot wingspans. There reason we never see any insect so big anymore is due to the fact that they breathe through their skin; in today's atmosphere, the level of oxygen wouldn't be enough to sustain anything to huge.

[Shervz0r]

Yeah, I love this stuff too but I really don't know how statements regarding hunting behavior and even skin color can be made from fossil records:
"[Pterygotus] lived in shallow coastal areas, hunting fish, trilobites, and other animals using stealth. It would have ambushed its prey by burying itself in sand. Then, when a fish or other unwitting animals came within range, Pterygotus would rise up and grab it with its claws."

Granted this is Wiki, but still, how can we be sure that the dinosaurs we imagine are properly colored?

Megalodon reigns supreme as the creature I am most terrified of

[Corax]

Yeah, I love this stuff too but I really don't know how statements regarding hunting behavior and even skin color can be made from fossil records:
"[Pterygotus] lived in shallow coastal areas, hunting fish, trilobites, and other animals using stealth. It would have ambushed its prey by burying itself in sand. Then, when a fish or other unwitting animals came within range, Pterygotus would rise up and grab it with its claws."

Granted this is Wiki, but still, how can we be sure that the dinosaurs we imagine are properly colored?

Megalodon reigns supreme as the creature I am most terrified of

Well I think that it's mostly based off of comparisons to modern day animals. You're right though, some statements are a bit far-reaching. To further reinforce this though is an example of the opposite: with plesiosaurs (and pliosaurs, all of those 4 finned reptiles) they have four fins, a paddle configuration not seen in any modern creatures (according to Wikipedia). So, it's an even larger educated guess as to how they would have moved.

And yes, Megalodon would be horrifying. Deinosuchus is another super-predator to be terrified of, haha. Aw wait, I checked the data and current estimates put Deinosuchus at a smaller scale than before. No more horrible 50 foot alligators.

[Shervz0r]

Deinosuchus is another super-predator to be terrified of, haha. Aw wait, I checked the data and current estimates put Deinosuchus at a smaller scale than before. No more horrible 50 foot alligators.

damn



man...that would be so horrible!

[Corax]

I guess the most recent estimate is still pretty big, well, considering it's twice the size of the largest saltwater crocodiles it really would be horribly large.

Another fearsome prehistoric aquatic creature (from the Devonian period! I've always loved the Devonian period, good old fish) would be Dunkleosteus.

[Dunkleosteus,] measuring up to 10 metres (33 ft) and weighing 3.6 tonnes (4.0 short tons)

(I think this mural is actually from the Royal Tyrell Museum of Paleontology, where they also have a life-sized plaster cast of the impressive bony skull)

and to scale:

[Shervz0r]

That chick isn't smiling. Bite her, Dunklefish!

[Corax]

That chick isn't smiling. Bite her, Dunklefish!

HA!

[bucky]

Largest Prehistoric Organisms

A 17 foot tall sloth! This dude must've ruled-



http://en.wikipedia....iki/Megatherium

[bucky]

also here's proof that the megalodon is serious business-

[Arm Cannon]

thank god they're dead

[raubhimself]

Try to imagine yourself in the Cretaceous Period. You get your first look at this "six foot turkey" as you enter a clearing. He moves like a bird, lightly, bobbing his head. And you keep still because you think that maybe his visual acuity is based on movement like T-Rex - he'll lose you if you don't move. But no, not Velociraptor. You stare at him, and he just stares right back. And that's when the attack comes. Not from the front, but from the side, ::whoosh:: from the other two 'raptors you didn't even know were there. Because Velociraptor's a pack hunter, you see, he uses coordinated attack patterns and he is out in force today. And he slashes at you with this... a six-inch retractable claw, like a razor, on the the middle toe. He doesn't bother to bite your jugular like a lion, say... no no. He slashes at you here... or here... or maybe across the belly, spilling your intestines. The point is... you are alive when they start to eat you. So you know... try to show a little respect.



I always liked these guys.

[Rize]

The small one is a modern great white... for his larger ancestor, a person would be little more than a tasty snack.

[kareshi]

I love dinosaurs and fossils. Especially shark teeth.