$10R - HU - facing big river bet

[LCposter]

PokerStars No-Limit Hold'em Tourney, Big Blind is t40000 (2 handed) internettexasholdem.com

Hero (t458060)
Button (t1381940)

Preflop: Hero is BB with T[img]/images/graemlins/spade.gif[/img], 3[img]/images/graemlins/diamond.gif[/img].
Button calls t20000, Hero checks.

Flop: (t64000) J[img]/images/graemlins/spade.gif[/img], A[img]/images/graemlins/club.gif[/img], T[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">Button bets t56400</font>, Hero calls t56400.

Turn: (t176800) 7[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, Button checks.

River: (t176800) 4[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">Button bets t180000</font>, Hero ???

Final Pot: t536800

Reads on villian: Pretty solid, but certainly mixing it up. Playing a little tight pre-flop (i.e. letting me raise and steal more than my share of blinds, but sometimes 3-betting). I think his PF raising range is about Ax+,K8+,QT+, PPs, SCs and one-gappers above 76, with him only raising the weaker hands 50% of the time. Post-flop, he's been fairly aggressive with bets and CRs, but he's also made several laydowns. I certainly can't call him a maniac or a calling station. Only a few hands have showed down, and he's bet draws and air along with solid hands, so he's good at mixing his play.

I thought about this one for a while. My hand is nothing more than a bluff catcher, but the board and his line feel like monster or air to me.

Call or fold?