Chinese Fossils Suggest an Early Amphibian Adapted to the Open Sea

Its fossils occurred away from ancient land, and their chemical signatures resemble seawater.. The article combines the geological setting with the chemical signatures; armour alone does not establish habitat.

Clue: Its bony armour covered a flattened body. The skeletons were preserved in rocks that formed away from land, while chemical signatures in the fossils resemble those of seawater from the same period. Together, the observations support the researchers' interpretation that the animal lived in a marine environment.

The proposed role of armour and organs in handling salt. The passage qualifies the proposed salt-tolerance mechanism because physiological details are not fully preserved.

Clue: It may be the first fully marine amphibian known from the fossil record. The proposed role of its armour and organs in tolerating salt remains a hypothesis; the fossils do not preserve every detail of its physiology.