“Meet the turtle frog (Myobatrachus gouldii).
The turtle frog is one of the most fossorial (living under ground) species of frog in Australia. It lives in the semi-arid regions of south-western Australia. Often inhabiting sandy soils where any free-standing water is quickly lost to the soil and evaporation.
During the mating season, males will call on or just under the sand surface to attract a female. This usually occurs just after rain, which is a rare event. Females will locate calling males, but they do not mate straight away. They will bury themselves up to 1 metre and build an underground nest. Here they mate and lay their eggs. Strangely, the eggs do not develop into tadpoles but directly into small froglets.
This direct development has evolved independently in many frog species. However it is usually to reduce the high level of tadpole predation that occurs in the permanent water bodies of very wet environments where the eggs are not at risk of drying up. Conversely, the turtle frog has evolved this method of breeding as a means of surviving in very dry environments.”
I remember seeing a documentary on these guys—they’re extremely interesting and have the funniest mating piles ever ahaha