Largest amphibian ever

- Who
- Prionosuchus plummeri
- What
- 9 metre(s)
- Where
- Brazil
- When
- September 1991
The largest amphibian ever is Prionosuchus plummeri, a prehistoric temnospondyl of aquatic, predatory lifestyle that existed during the early Permian Period, approximately 299–272 million years ago, in what is today north-east Brazil. Based upon its fossil remains uncovered so far, it is estimated to have attained a total length of up to 9 m (29 ft 6 in). Long and slender in overall body shape, with short legs but very slim, lengthy jaws, it is believed to have occupied during the Permian the ecological niche occupied nowadays by crocodilians, especially the similar-shaped gharial. The superlative specimen of Prionosuchus found in the Pedra de Fogo Formation is described in the journal Palaeontology in September 1991 by C Barry Cox and P Hutchinson.
Prior to P. plummeri, the largest amphibians were thought to belong to the genus Mastodonsaurus, another temnospondyl, represented by three species, all from the Middle Triassic period, approximately 247–237 million years ago, and all inhabiting swampland regions of what is today Europe. Mastodonsaurus may have attained a total length of up to 8 m (26 ft 3 in), although more recent estimates have erred more towards 6 m (19 ft 8 in).
The first species to be described was M. giganteus in 1828, and was originally thought to have been frog-like in shape, but nowadays all three species are recognized as having been long, somewhat crocodile-like in form but with an extra-large head.