Which race is the oldest: the Ents or the Elves?

[Peter_20]

I frequently hear that the Ents are the oldest living beings.
Yeah, but why does Treebeard go on about how the Elves "awoke" them, and turned them from trees into Ents?
That must mean that the Elves are the oldest living beings, and this is even stated in that song that Treebeard sings - "eldest of all, the Elf-children"; but Treebeard obviously "belongs to the oldest living race in the world", or something.

What is correct? :confused:

[Landroval]

I tend to think that ents are older. For one, the passage in LotR doesn't imply that elves awoke the ents, only that they woke up talked to trees:
But some of my trees are limb-lithe, and many can talk to me. Elves began it, of course, waking trees up and teaching them to speak and learning their tree-talk. They always wished to talk to everything, the old Elves did.
as can be seen from the context, the issue is talking trees.

The passage in Silmarillion about the coming of ents also places them at least at the time of the coming of the elves:
Do then any of the Valar suppose that I did not hear all the Song, even the least sound of the least voice? Behold! When the Children awake, then the thought of Yavanna will awake also, and it will summon spirits from afar, and they will go among the kelvar and the olvar, and some will dwell therein, and be held in reverence, and their just anger shall be feared. For a time: while the Firstborn are in their power, and while the Secondborn are young.
More to the point, Tolkien calls ents the "eldest of living rational creatures" in Letter #131.

[Jon S.]

... said Yavanna, ... "Would that the trees might speak on behalf of all things that hve roots, and punish those that wrong them!"

"This is a strange thought," said Manwe.

"Yet it was in the Song," said Yavanna, "For while though wert in the heavens and with Ulmo built the clouds and poured out the rain, I lifted up the branches of great trees to receive them, and some sang to Illuvatar amid the wind and the rain."

Then Manwe sat silent, and the thought of Yavanna that she had put into his heart grew and unfolded; and it was beheld by Illuvatar. Then it seemed to Manwe that the Song rose once more about him, and he heeded now many things therein that though he had heard them he had not heeded before. ...

...

"Nay," [Manwe] said, "only the trees of Aule will be tall enough. In the mountains the Eagles shall house, and hear the voices of those who call upon us. But in the forests shall walk the Shepherds of the Trees."

Then Manwe and Yavanna parted for that time, and Yavanna returned to Aule; and he was in his smithy, pouring molten metal into a mould. "Eru is bountiful," she said. "Now let thy children [the Dwarves] beware. For there shall walk a power in the forests whose wrath they will arouse at their peril."

"Nonetheless they will have need of wood," said Aule, and he went on with his smith-work.

S Ch. 2 (Of Aule and Yavanna)