The dire wolf lived in the Americas during the Late Pleistocene epoch (125,000–10,000 years ago).The species was named in 1858, four years after the first specimen had been found.
Ninety-five percent of the activity of Oxalic Acid from the year 1950 is equal to the measured activity of the absolute radiocarbon standard which is 1890 wood.Two subspecies are recognized, these being Canis dirus guildayi and Canis dirus dirus.The dire wolf probably evolved from Armbruster's wolf (Canis armbrusteri) in North America.A copy of this paper may be found in the Radiocarbon Home Page The radiocarbon age of a sample is obtained by measurement of the residual radioactivity. T (National Institute of Standards and Technology; Gaithersburg, Maryland, USA) Oxalic Acid I (C). The activity of 1890 wood is corrected for radioactive decay to 1950.This is calculated through careful measurement of the residual activity (per gram C) remaining in a sample whose age is Unknown, compared with the activity present in Modern and Background samples. Thus 1950, is year 0 BP by convention in radiocarbon dating and is deemed to be the 'present'.