Crassigyrinus, the "thick tadpole," was the rebellious teenager of life's transition to land. This two-meter-long creature was one of the first tetrapods, or animals with four legs. You might not have noticed, though, because of its tiny limbs! Crassigyrinus' limbs were likely vestigial because it had readapted to a fully aquatic life-style. This left it with a slender, eel-like profile that was perfect for prowling the early Carboniferous waters it called home. Following the teenage trend of ungainly proportions, its head and jaws were gigantic in order to accommodate massive eyes and two rows of teeth. These adaptations made Crassigyrinus an effective predator. Its streamlined body helped it move swiftly through the water, while its hefty head tore into its prey of choice: small vertebrates, like fish. This wee beastie swam in the swamps and lakes of what is now Scotland. Its large eyes were perfectly adept at peering through the murky water that it lived in, and may have also provided nocturnal vision for when it snuck out past curfew and tried to go party at the pub. Other frequenters of the Scottish swamps included Crassigyrinus' the small fish that it feasted upon, anthracosaurs like Proterogyrinus, terrestrial temnospondyls, and an assortment of arthropods.