George Gheverghese Joseph of the University of Manchester and colleagues said the scholars at southwestern India's Kerala School identified the "infinite series" -- one of the basic components of calculus -- in about 1350. Joseph said that discovery is attributed to Newton and Gottfried Leibnitz at the end of the 17th century.
The finding by Joseph and Dennis Almeid of the University of Exeter reveals the Kerala School also discovered what amounted to the pi series and used it to correctly calculate pi to nine, 10 and later 17 decimal places.
The British researchers said there's strong circumstantial evidence the Indians passed on their discoveries to mathematically knowledgeable Jesuit missionaries during the 15th century. That knowledge, they argue, might have eventually been passed on to Newton himself.
Joseph said he is working on the third edition of his book "The Crest of the Peacock: the Non-European Roots of Mathematics."