And this view http://www.themodernantiquarian.com/post/41668 clearly makes it an undifferentiates passage tomb. Nice!

Interesting note in the folklore post:

"Also he pointed out that the name for the area Ardcroney means Ard being Big, Croine. And locally that is believed who was found in the mound Ard Croine."

Croineir (with a few accents) is actually the Irish for <i>coroner</i>. If croineir has the same roots as coroner, then it's crown related, but the Irish for crown is <i>coroin</i>. The alternative is that croineir is related to the Greek khronos and time, because chronicle (croinic in Irish) means book of time or book of annals, so a croineir could tell the story of someone's death.

Interesting and curious one.

Does the Tipp inventory say this is a Linkardstown Kist? If so then they are very, very wrong. If so then I imagine the archaeologist who excavated it must have thought "North Tipp doesn't have passage tombs, so it must be something else!", and bottled out of giving it its true classification.

Linkardstown kists are polygonal closed chambers, not long, thin, narrowing four-sided structures. This quote too, "There is a stone at right angles to the SW side of the structure 1.2m from the inner end. This, in combination with a rough wall divides it in two." makes it more a passage tomb. The 3350bce RC date also seems too old for a Linkardstown-style burial, but I might be wrong there. The odd thing about it is the skeletal burials, which also may have led to the odd conclusion, because not many passage tombs have these.

If there is a 'stone at right angles to the SW side' then that also implies that the passage points NE or NW (I can't see that stone in your pictures), classic passage tomb alignment.