freeze tolerance

ad-cn  asked:

Koolasuchus sure was one huge amphibian, wasn't it?

It sure was - but that’s not necessarily the most interesting thing about it!

Koolasuchus was a salamander-like animal that grew to lengths of over 15 feet.  It lived in southern Australia, and is believed to have been an aquatic ambush predator similar to a crocodile.  It’s perhaps most famous for its appearance on Walking With Dinosaurs, where it’s shown preying on the small ornithopod Leaellynasaura.

Despite its salamander-like appearance, Koolasuchus has no direct living relatives.  It belongs to an extinct family of amphibians called Chigutisauridae.  The chigutisaurs belonged to Temnospondyli, a primitive order of amphibians that originated during the Carboniferous period.

The temnospondyls were a massively diverse group of animals.  Some were fully aquatic, while others were adapted to life on land; some were as small as modern frogs and salamanders, while others were the biggest amphibians in Earth’s history.  Unfortunately, they began to decline around the Permian/Triassic boundary, as Earth’s climate grew more arid and reptiles began to diversify on land.

Most temnospondyls went extinct by the Jurassic period, except for one small group - the brachyopoids, all of which were large Koolasuchus-like ambush predators.  The brachyopoids were divided into two families - Brachyopidae, and Chigutisauridae (the group to which Koolasuchus belongs).

Koolasuchus is the latest known brachyopoid (and temnospondyl in general), living 120 million years ago, during the Early Cretaceous period - 80 million years after the extinction of all other temnospondyls.  What allowed it and the other brachyopoids to survive for so long after all their relatives went extinct?

Jurassic and Cretaceous brachyopoids all dwelled in very cold regions - either in China, or in the southern parts of Gondwana (South America, Africa, Antarctica, and Australia).  They likely had some sort of adaptation to survive in cold weather - an adaptation lacked by the crocodilians that occupied the same niches in warmer parts of the world.  As the continents drifted, climates changed, and these parts of the world became warmer, crocodilians spread to new areas, and the brachyopoids became extinct.

I’m not aware of any paleontological evidence for how Koolasuchus and its relatives survived in the cold, so I’m going to toss out a piece of wild speculation: Like the modern wood frog, Koolasuchus might have been capable of surviving extreme winter conditions, even being able to tolerate the freezing of its blood.  It would hibernate until the spring thaw - possibly underwater, in order to avoid the notice of winter-active predators, like dinosaurs.

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The wood frog (Lithobates sylvaticus) has gained much attention over the past century due to its miraculous ability to freeze and then defrost again just as if nothing ever happened. It’s the frog version of science fiction and cryogenics.

Similar to other northern frogs that hibernate close to the surface in soil and/or leaf litter, wood frogs can tolerate the freezing of their blood and other tissues. Urea is accumulated in tissues in preparation for overwintering, and liver glycogen is converted in large quantities to glucose in response to internal ice formation. Both urea and glucose act as “anti-freeze” to limit the amount of ice that forms and to reduce osmotic shrinkage of cells. Frogs can survive many freeze/thaw events during winter if no more than about 65% of the total body water freezes.

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limeadepeelsarchive2017  asked:

on the subject of monster haus, how do jack and bits get together?

WELL. Okay this AU mostly follows the canon plot, except you know, with monsters. So i think it would go down mostly the same way, with them initial disliking each other and that growing into a friendship. 

Like, Jack might be a little biased, because he likes having Monsters on his team. Big, tough guys. Giants, trolls, goblins, wolves and vampires. It’s not that Jack has anything against witches really, they’ve actually had magic users on the team, and even humans, but this tiny kitchen witch who freaks out whenever he’s touched on the ice is not…what Jack asked for. 

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So somebody needs to write a fanfic where Leonard suffers from chronic pain.

After all, we’ve all headcanoned that his torso is covered in scars from Lewis’ abuse + protecting Lisa from the same fate, but what if we went a step farther and that physical damage was so severe that he is always in pain.

Just getting out of bed every morning is a chore, but he does it because he’s stubborn and refuses to show weakness, and because he does not begrudge one second of this pain since it means that Lisa is protected from it.

The cold from his gun only enhances the pain, which is part of why he’s always completely bundled up; he’s trying to minimize that pain. The huge parka is only partly a fashion statement.

He doesn’t like being touched because it focuses his attention on his body and he’s trained himself not to notice it, but when anybody touches him all he can feel are the aches and pains that years of abuse left behind.

People wonder why he has such a high pain tolerance (freeze his own hand off nbd, get shot by a pirate blaster and is rushing off to help Sara fight Mick right when he regains consciousness, Mick beats him black and blue and he’s sauntering around like normal the next day) but nobody (not even Lisa) knows that it’s because he’s used to pain. When you are constantly hurting, adding a little bit more to that really doesn’t make much of a difference.

Just… chronic pain Len please and thank you!

Lobivia famatinensis is in the family Cactaceae. This species is native to the Famatina mountains in Argentina, where it grows at altitudes of over 9,000 feet. The spines of this cactus extend parallel to the stem compared to other cactus species which have spines that extend outward. Lobivia famatinensis grows very slowly and is prone to overwatering, but can tolerate below freezing temperatures during the winter months.

NOT DEAD YET

The wood frog has garnered attention by biologists over the last century because of its freeze tolerance. Antifreeze-like blood lets frogs freeze and thaw with winter’s whims. They endure this annual popsicle phase with help from cryoprotectants, substances circulating in their blood that lower the freezing point of their body fluids (via Iris Kronenburg).

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The Dance at Alder Cove - Youth/Father/Geezer  I see you