Tree squirrel Tree squirrel Tree squirrels are the members of the squirrel family (Sciuridae) commonly just referred to as "squirrels". They include over a hundred arboreal species native to all continents except Antarctica and Oceania. They do not form a single natural, or monophyletic group; they are related to others in the squirrel family, including ground squirrels, flying squirrels, marmots, and chipmunks. The defining characteristic used to determine which species of Sciuridae are tree squirrels is dependent on their habitat rather than their physiology. Tree squirrels live mostly among trees, as opposed to those that live in burrows in the ground or
Underwater habitat depth of approximately 12 m. A concept design by internationally recognized conceptual designer and futurist Phil Pauley. The Sub-Biosphere 2 is the original self sustainable underwater habitat designed for aquanauts, tourism and oceanographic life sciences and longterm human, plant and animal habitation. SBS2 is a seed bank with eight Living Biomes to allow human, plant and fresh water interaction, powered and controlled by the Central Support Biome which monitors the life systems from within its own operations facility. Underwater habitat Underwater habitats are underwater structures in which people can live for extended periods and carry out most of the basic