Yeah, but frogs and tadpoles are common across the world, so I find it hard to believe that the writer was not aware of tadpoles.

Out right falsehoods were not uncommonly produced as true facts of distant lands. For example, it is common knowledge that Ethiopians and natives of of the Indian subcontinent do not have heads, but rather have their face embedded directly into their chest.

https://en.wikipedia.org/wiki/Headless_men

Or if that is too fanciful, consider that the salamander’s natural habitat is fire.

https://en.wikipedia.org/wiki/Salamanders_in_folklore