Dolmens of Russia

I came across a post in FB about the Dolmens in Russia and came across this link. Whats is interesting is how come these Dolmens look strikingly similar to the ones we find in South India.I have seen such Dolmens in Nilgiris in my school days. I have seen photos of Dolmens across the world and find them almost similar in construction. That's the most intriguing part. Can some one explain? http://www.ancient-origins.net/ancient-places-europe/25000-year-old-buildings-found-russia-006215