around equatorial Pangaea and around the Paleo-Tethys Ocean. Several adaptations to piscivory evolved with some groups having crocodile-like skulls with slender snouts, and presumably had a similar life-style (Archegosauridae, Melosauridae, Cochleosauridae and Eryopidae, and the reptile-like suborder Embolomeri). Others evolved as aquatic ambush predators, with short, broad skulls that allowed for opening the mouth by tipping the skull back rather than dropping the jaw (Plagiosauridae and the Dvinosauria). In life they would have hunted rather like the modern day monkfish, and several groups are known to have retained the larval gills into adulthood, being fully aquatic. The Metoposauridae adapted to hunting in shallows and murky swamps, with ∩-shaped skull, much like their Devonian ancestors. In Euramerica, the Lepospondyli, a host of small, mostly aquatic amphibians of uncertain phylogeny, appeared in the Carboniferous. They lived in the tropical forest undergrowth and in small ponds, in ecological niches similar to those of modern amphibians. In the Permian, the peculiar Nectridea found their way from Euramerica to Gondwanaland. Decline From the middle of the Permian, the climate dried up, making life difficult for the amphibians. The terrestrial reptiliomorphs disappeared, though aquatic crocodile-like Embolomeri continued to thrive until going extinct in the Triassic. The diverse lepospondyl inhabitants of the undergrowth disappear from the fossil record, among them the snake-like Aïstopoda. With the close of the Paleozoic, most of the Permian groups disappeared, with the exceptions of the Mastodonsauroidea, Metoposauridae and Plagiosauridae, who continued into the Triassic. In the early Triassic these groups enjoyed a brief renaissance in the waterways of continental shallows, with large forms like Thoosuchus, Benthosuchus and Eryosuchus. Their ecological niches were probably similar to those of modern-day crocodiles, as fish hunters and riverside carnivores. All groups developed progressively weaker vertebrae, reduced limb ossification and flatter skulls with prominent lateral line organs, indicating the late Permian/early Triassic temnospondyls rarely if ever left the water. An extremely large brachyopid (likely a plagiosaur or a close relative) is estimated to have been 7 meters long, and probably just as heavy as the Permian Prionosuchus. With the rise of the real crocodiles in the middle Triassic, even these Temnospondyli went into decline, though some hung on to at least early Cretaceous on the southern Gondwanaland, in regions too cold for crocodiles. Origin of modern amphibians There is today a general consensus that all modern amphibians, the Lissamphibia, have their origin in labyrinthodont stock, but this