Frogs have never drawn attention to their jaws, until now. A group of researchers has located a group of amphibians that live in the streams of Southeast Asia with dwarf tusks protruding from their lower jaw, a bone adaptation never seen to date, as explained in a study published in the journal PLOS ONE.
In general, the teeth of frogs are like small pointed spikes in the upper jaw, but this group of frogs, which lives in the streams of Sulawesi (Indonesia) has a strange adaptation, in which two bony "fangs" stand out that protrude on the bottom.
According to scientists, this species, named Limnonectes phyllofolia (leaf nester), uses these fangs to fight among themselves for territory and mates. Sometimes even to hunt hard-shelled prey such as giant centipedes and crabs.
"This new species is small compared to other fanged frogs on the island where it was found, about the size of a quarter," explains postdoctoral researcher at Chicago's Field Museum and lead author of the study, Jeff Frederick.
It is not the only peculiarity of this new species. Team members also observed nests of eggs in tree leaves and on rocks. Another striking discovery, because these amphibians lay eggs encapsulated in gelatin in the water to prevent them from drying out. It is not common for them to do it elsewhere.
"Normally, when looking for frogs, we scan the banks of streams or wade through them to see them directly in the water. However, after repeatedly monitoring the nests, the team began to find attendant frogs sitting on leaves hugging their small nests," continues Frederick.
The surprises did not end there. After observing these small amphibians, they found that those taking care of the clutches of eggs were all males. "The behavior of males as egg guardians is not totally unknown in all frogs, but it is quite uncommon," adds the author of the study.
Researchers believe that this reproductive behavior may be related to the size of the tusks. Some of the frogs' relatives have larger fangs, which helps them avoid competition for places along the river to lay their eggs in the water. However, these put them far away, so they may have lost the need to have such large and imposing fangs.
