Sheherzad Raza Preisler in Nautilus:
Suicide-bombing ants. Bone-breaking frogs. Spit-flinging arachnids. Back-birthing toads. And bone-dissolving worms. What do all of the above have in common? Specialized adaptations. They’ve become so accustomed to their distinct habitats that they’d be more likely to perish, compared to their more generalist relatives, if moved to a slightly different locale. Each of them, as a result, make the variety of beak sizes among Darwin’s famous finches seem mundane by comparison. That’s because each of these five species below illustrates the seemingly eccentric paths evolution can take groups of organisms on—they’ve become, with time and struggle, distinctive offshoots of their less-specialized ancestors.
The Wolverine Frog (Triobatrachus robustus)
Native to Cameroon, Africa, the Wolverine Frog boasts an uncommon adaptation for living amphibians: claws. Scientist David C. Blackburn and his team released a study on the frog in 2008, explaining that these claws are unique due to their lack of keratinous covering. It was initially believed that these talons existed purely to provide a better grip for the frogs as they were about to leap, but Blackburn postulated that they were actually for defense, as they had the capacity to create deep punctures. Cameroonians hunt the frog using machetes and spears to not get injured handling them directly. These claws emerge from the frog’s extremities by breaking through their ventral skin, resulting in a “traumatic wound in which the skin is torn.” It’s still unknown whether or not the original connection between the bony nodule and terminal phalanx regenerates once the claws are retracted.
More here.