(i.e. Elrond or Elros)

This, to some (including some Silmarillion readers as well as those frequently in the Tolkien Gateway), is an interesting topic. Neither J. R. R. Tolkien (or Christopher Tolkien, for that matter) does not state who is the older of any twin pairs. Most sources (including the Silmarillion) only imply Elrond is older, but at one point, they imply Elros is older. So, which one is older?

Edit: Forgot to mention, at one point, Christopher Tolkien later inverted the order. Which follows canon?

Here is my opinion on things. I am getting oriented toward Elrond being the older. Looking at Silmarillion family trees, Elrond is listed as the older twin (the oldest child is on the left of all the children, and so on until the youngest child on the right). This can also be an indirect reference to the Children of Iluvatar: Elrond, being the older twin, chooses the Elvish fate (Elves are also known as the Firstborn, and Men are the Second Children).

I would like to see your side of things, as well as provide a poll to make it easier to track of.

For those who don't know who the characters are (mostly for Elros's part), both are the twin sons of Earendil and Elwing. Elrond chose the Elvish fate and became, most famously, Lord of Imladris, while Elros chose the mortal fate and became the first King of Numenor, and is the patriarch of the Kings of Gondor and Arnor as well as the Dunedain Chieftains.