Which Came First: Vareniki or Pelmeni?

What’s the difference between vareniki and pelmeni? Both are dumplings. Is it a question of who invented them? Even that is hard to decide. It’s amazing that passions are not raging over vareniki the way they are over borscht. Almost every nation has its own kind of dumplings: Italian ravioli, Japanese gyoza, Georgian khinkali, Asian…