The smallest of the statues measures less than one millimeter in height.
A painting from the 13th century fetched $20 million more than expected at auction.
The panel is believed to be the work of a 13th-century Florentine artist called Cimabue, who was active from 1272 to 1302 and also went by the name of Cenni di Pepo.
"Five centuries after his death, during which thousands of scholars have read his works, have discussed his discoveries and have investigated his life from every point of view, there is still a lot to know about Leonardo da Vinci, the 'Renaissance Man'," Dr. Davide Lazzeri, co-author of the new study told Newsweek.
Italian academics believe they have discovered the Florentine master's earliest known work and signature, thanks to an almost invisible code.
He will also step down from the hedge fund Renaissance Technologies.
He spent millions to help put Donald Trump in the White House.