Unfortunately, their calculations of Ming's age weren't possible without cracking open the clam's shell, so researchers didn't realize they were in possession of what was likely the world's oldest living animal â until they had already killed it.
Natural history. 1  All gerbils have long hind feet and fairly large ears and eyes, but there is variation among other characteristics. Body form varies from stout and compact to slender and gracile. 2  Most gerbils are nocturnal; a few species, however, are active only in early morning and evening or during the day. Gerbils walk and scamper on all four limbs and flee in running leaps when alarmed. Some construct short, simple burrows, but others construct elaborate underground galleries.
The nocturnal mammalâs eye has adapted to the dark. What diurnal mammals see as pitch-black darkness, nocturnal mammals see as dim light or shades of gray. Nocturnal mammals have proportionally larger eyes than mammals who are awake during the day; a tarsierâs eye is so large it canât even move in its socket. Their pupils are also able to open more widely in low light than the diurnal mammalâs pupils.