The reliance on fur for insulation, rather than blubber, suggests sea otters are what in terms of evolutionary adaptation to the sea?

Answer

A snapshot of mammals recently returned to the marine environment.

Their dependence on fur instead of blubber is an evolutionary marker indicating they returned to the marine environment relatively recently.

The reliance on fur for insulation, rather than blubber, suggests sea otters are what in terms of evolutionary adaptation to the sea?
animalwildlifecountrymarine animalOtter