Very strange crocodiles have entered a cave, devoured bats, and are now undergoing mutations.

Dwarf crocodiles (Osteolaemus tetraspis) were discovered by scientists in the Abanda cave system in Gabon. The skin of this species has turned orange due to bathing in guano, but researchers still do not know how long they have been there. Furthermore, scientists believe that the cave-dwelling dwarf crocodiles are likely evolving into a completely new species, according to Live Science.

The unusual crocodiles were first identified and studied by scientists back in 2010, and in a 2016 study, the team compared them to their forest-dwelling relatives—results showed differences between them. Researchers note that it is still unknown how many crocodiles inhabit these caves and how long they have been living underground. However, scientists speculate that the animals may have been there for thousands of years, and moreover, today the crocodiles might also be in the process of evolving into a new species.

It is known that this species lives deep inside one of Gabon's cave systems and is characterized by its striking orange skin. Dwarf crocodiles dwell in complete darkness, feeding on bats and swimming in liquid guano—the excrement of bats.

During observations of this species, scientists found that its members eat crickets and bats. Interestingly, overall, members of this species seem to be in better condition than those living in the forest. The team believes that their thriving condition is likely linked to the abundance of available prey and the absence of predators.

It is suggested that cave crocodiles lay their eggs at the entrance of the caves, after which the young descend into the darkness. When the crocodiles reach adulthood, scientists believe they no longer leave the caves.

According to the lead author of the 2018 study, conservation biologist Matthew Shirley from the International University of Florida, the unusual orange skin of the crocodiles is likely a result of their swimming in bat guano. Over time, this exposure apparently causes a chemical bleaching of the crocodiles' skin.

Genetic analysis of the animals, which has not been published, suggests that cave dwarf crocodiles may also be mutating right now. According to co-author Richard Oslely from the French Institute for Development Research, today the crocodiles in the Abanda caves stand out as an isolated genetic group: one group of DNA variants inherited from a parent found in cave crocodiles was completely absent in forest crocodiles.

The authors of the study claim that such genetic change is evidence that cave crocodiles are evolving into a new species. Unfortunately, scientists cannot accurately predict when this transformation will conclude.