Guenther's Marsupial Frog (Gastrotheca guentheri) is a species of frog in the Hemiphractidae family. It is found in Colombia and Ecuador. Its natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical moist montanes, and rivers. It is threatened by habitat loss.
It is the only frog with true teeth in its lower jaw. Recent studies have proposed its teeth have re-evolved after being absent for over 200 million years, challenging Dollo's law.
- ^ Wiens, J. J. (2011). "Re-Evolution of Lost Mandibular Teeth in Frogs After More Than 200 Million Years, and Re-Evaluating Dollo's Law". Evolution: no. doi:10.1111/j.1558-5646.2011.01221.x.