- "This boy bites off more than he can chew."
Crassigyrinus scoticus ("Thick Tadpole"), also called "The Swamp Monster", was a giant, aquatic, mysterious, pretatory, two-meter (6 ft) long, stem-tetrapod, prehistoric amphibian from the Carboniferous period of Scotland and whose fossils have only ever been found in Scotland, notable for combining bizarre specializations such as tiny forelimbs, with a number of primitive features.
Crassigyrinus lived during the middle to the end of the Carboniferous period, living along side giant insects, primitive reptiles, and even other amphibians. It was one of the top predators of its time.
Crassigyrinus measured two meters long and this bizarre tetrapod had small, thin, but noticeable hind limbs and vestigial forelimbs, making it look a bit like an elongated frog (or a giant tadpole, hence its Greek name). This eel-like creature seemed to have spent most, if not, all of its time in the water, and its double rows of sharp teeth point to an unmistakably carnivorous diet.
Not like the Proterogyrinus, Crassigyrinus's legs were short and stubby, so it could not leave the water. Crassigyrinus scoticus was perfectly adapted to life underwater as it had gills and a strong and powerful tail. These have given rise to arguments about its taxonomic status. Not only is it taxonomically bizzare, it must also have been a remarkable and formibable animal when alive. Crassigyrinus had a pair of large eyes, suggesting that it was either nocturnal, or lived in very murky water.
Although these creatures were slimy and powerful, they still has these tiny limbs, only for an animal a quarter of their size, so they weren’t very good on the land. And these amphibians lived in the shallows.
To catch fish and other amphibians, these predators burst out much like a modern-day pike. They were ambush predators with lengthy jaws and they could open their jaws really wide, making it the perfect snap trap. They waited in ambush and whenever prey came nearby, they attacked anything that they could dismember – fish, amphibians – with a double row of fearsome teeth in their mouth, similar to a shark.
Its favorite food was fish and other amphibians, but it may have also attacked some of the giant arthropods of its time including the giant dragonfly Meganuera.