Mexican Burrowing Toad
The Mexican Burrowing Toad is genetically unique in a number of ways. According to EDGE, Mexican Burrowing toads are:
“The only species, within the only genus of the family Rhinophrynidae, and with over 190 million years of independent evolution, the Mexican burrowing toad is the most evolutionarily distinct amphibian species on Earth today; a fruit bat, polar bear, killer whale, kangaroo and human are all more similar to one another than this species is to any other amphibian.”
Except this is completely wrong, because it’s still more closely related to other frogs than it is to caecilians, and frogs and caecilians are evolutionarily separated by like 300 million years.