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Nototamias
''Nototamias'' is a genus of fossil ground squirrels from the Miocene of North America. Species include ''Nototamias hulberti'' Pratt and Morgan, 1989; ''Nototamias ateles'' (Hall, 1930); and ''Nototamias complicatus'' Korth, 1992. Although the genus, characterized by fused roots on the lower cheekteeth, is often regarded as closely related to the chipmunk Chipmunks are small, striped rodents of subtribe Tamiina. Chipmunks are found in North America, with the exception of the Siberian chipmunk which is found primarily in Asia. Taxonomy and systematics Chipmunks are classified as four genera: '' ...s, and ''N. ateles'' has even been regarded as a species of '' Tamias'', evidence for this relationship is poor and ''Nototamias'' may instead be near the origin of the Marmotini.Goodwin, 2008, p. 356 References Literature cited *Goodwin, H.T. 2008. Sciuridae. Pp. 255–376 in Janis, C.M., Gunnell, G.F. and Uhen, M.D. (eds.). Evolution of Tertiary Mammals of Nort ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chipmunk
Chipmunks are small, striped rodents of subtribe Tamiina. Chipmunks are found in North America, with the exception of the Siberian chipmunk which is found primarily in Asia. Taxonomy and systematics Chipmunks are classified as four genera: ''Tamias'', of which the eastern chipmunk (''T. striatus'') is the only living member; ''Eutamias'', of which the Siberian chipmunk (''E. sibiricus'') is the only living member; ''Nototamias'', which consists of three extinct species, and ''Neotamias'', which includes the 23 remaining, mostly western North American, species. These classifications were treated as subgenera due to the chipmunks' morphological similarities. As a result, most taxonomies over the twentieth century have placed the chipmunks into a single genus. Joseph C. Moore reclassified chipmunks to form a subtribe Tamiina in a 1959 study, and this classification has been supported by studies of mitochondrial DNA. The common name originally may have been spelled "chitmunk", fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Squirrel
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 (genus ''Marmota'') or prairie dogs, while the smaller and less bushy-tailed ground squirrels tend to be known as chipmunks (genus ''Tamias''). Together, they make up the "marmot Tribe (biology), tribe" of squirrels, Marmotini, a clade within the large and mainly ground squirrel subfamily Xerinae, and containing six living genera. Well-known members of this largely Holarctic group are the marmots (''Marmota''), including the American groundhog, the chipmunks, the susliks (''Spermophilus''), and the prairie dogs (''Cynomys''). They are highly variable in size and Morphology (biology), habitus, but most are remarkably able to rise up on their hind legs and upright posture, stand fully erect comfortably for pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene followed the Oligocene and preceded the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by distinct global events but by regionally defined transitions from the warmer Oligocene to the cooler Pliocene Epoch. During the Early Miocene, Afro-Arabia collided with Eurasia, severing the connection between the Mediterranean and Indian Oceans, and allowing the interchange of fauna between Eurasia and Africa, including the dispersal of proboscideans and Ape, hominoids into Eurasia. During the late Miocene, the conn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tamias
''Tamias'' is a genus of chipmunks in the tribe Marmotini of the squirrel family. The genus includes a single living species, the eastern chipmunk (''Tamias striatus''). The genus name ''Tamias'' () means "treasurer", "steward", or "housekeeper", which is a reference to the animals' role in plant dispersal through their habit of collecting and storing food for winter use. The genus ''Tamias'' was formerly divided into three subgenera that, in sum, included all chipmunk species: ''Tamias'', the eastern chipmunk and other fossil species; '' Eutamias'', of which the Siberian chipmunk (''E. sibiricus'') is the only living member; and '' Neotamias'', which includes the 23 remaining, mostly western, species. These classifications are subjective, and most taxonomies over the twentieth century have placed the chipmunks in a single genus. However, studies of mitochondrial DNA show that the divergence between each of the three chipmunk groups is comparable to the genetic dissimilarity b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Rodent Genera
Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared years ago. It took thousands of years for writing systems to be widely adopted, with writing having spread to almost all cultures by the 19th century. The end of prehistory therefore came at different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. It is based on an old conception of history that without written records there could be no history. The most common conception today is that history is based on evidence, however the concept of prehistory hasn't been completely discarded. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
