a Roman historian who seems to have lived about the time of Cicero. The exact nature of his work is uncertain, although we know that in it he spoke of the time of Sulla. (Suet. Jul. 9.) Plutarch (Plut. Caes. 22) mentions an historian whom he calls Γανύσιος, and whom Vossius (de Hist. Lat. 1.12) considers to be the same as our Tanusius. Seneca (Epist. 93) speaks of one Tamusius as the author of annals; and it is not improbable that this is merely a slight mistake in the name, for Tanusius; and if this be so, Tanusius Geminus wrote annals of his own time, which are lost with the exception of a fragment quoted by Suetonins.
[L.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890