I say that because my research tells me that silly putty was developed in the 1940s.
From Wikipedia:
Origins of Silly Putty
Silly Putty was invented by James Wright of General Electric when he dropped boric acid into silicone oil. He was looking for a substitute for rubber. GE supplied the newly discovered dilatant compound to researchers around the world. None found a use for it, but they all loved playing with it.[1]
In 1943, Dr. Earl Warrick left the Mellon Institute of Industrial Research to join the newly formed Dow Corning Corporation. His research was refocused: help the war effort by developing a synthetic rubber substitute. Although he failed to produce a suitable rubber before the end of the war, one result of his experiments was a silicone bouncing putty. (“Forty Years of Firsts: The Recollections of a Dow Corning Pioneer," by Dr. Earl L. Warrick, McGraw-Hill Publishing Company, New York, 1990, pp. 27-28.)
The product was then commercialized by Peter Hodgson in 1949 after the marketing expert attended an informal "nutty putty" party where chemists were playing with the substance after hours. Renamed "Silly Putty" because of its main ingredient, silicone, the product was a smash hit.[2]
Raw Silly Putty polymer is available as Dow Corning 3179 Dilatant Compound. There are recipes for homemade silly putty using Elmer's Glue and boric acid. These produce a compound which is similar in chemical structure but is different in the elements which form that structure.
According to an MIT webpage on inventions:
Ironically, it was only after its success as a toy that practical uses were found for Silly Putty. It picks up dirt, lint and pet hair, and can stabilize wobbly furniture; but it has also been used in stress-reduction and physical therapy, and in medical and scientific simulations. The crew of Apollo 8 even used it to secure tools in zero-gravity.[3] Although Silly Putty is fundamentally the product of combining boric acid and silicone oil, one of the main ingredients in name-brand Silly Putty is elemental silicon (silicon binds to the silicone and allows the material to bounce 20% higher).
http://en.wikipedia.org/wiki/Silly_putty
The sillyputty.com web site says:
The History of the "Real Solid Liquid®"
Silly Putty® has been around for 50 years now, and in the past half-century, it's become an American toy classic. From its origins in a scientist's laboratory in 1943 and its introduction to the world in 1950, to its addition to the Smithsonian Institution, the fun and colorful history of Silly Putty® is one for the books!
http://www.sillyputty.com/history_101/history101.htm
That is why I'm very skeptical that the ancients had it. If they did, they probably would have had too much fun to get anything done.