Marmots are large ground squirrels in the genus Marmota, with 15 species living in Asia, Europe, and North America. These herbivores are active during the summer, when they can often be found in groups, but are not seen during the winter, when they hibernate underground. They are the heaviest members of the squirrel family.
Marmot
A Marmot with a Branch of Plums, 1605 by Jacopo Ligozzi
Marmota primigenia fossil
Image: Marmota baibacina
Ground squirrels are rodents of the squirrel family (Sciuridae) that generally live on the ground or in burrows, rather than in trees like the tree squirrels. The term is most often used for the medium-sized ground squirrels, as the larger ones are more commonly known as marmots or prairie dogs, while the smaller and less bushy-tailed ground squirrels tend to be known as chipmunks.
Ground squirrel
20,000-year-old Arctic ground squirrel mummy
California ground squirrel (Otospermophilus beecheyi) in a tree
Watchful "rock chuck" or yellow-bellied marmot (Marmota flaviventris) atop Mount Dana, Yosemite National Park in California