"Dark comedy" doesn't do it justice. Theatre Vertigo's season opener, Pterodactyls, is a bilious, hopeless thing, a wounded animal slowly bleeding to death on stage-as though from some vaguely ridiculous cause, like eating a plastic bag or getting hit by a bicycle. To strain the metaphor, the animal in question is the American Family, and the fatal wounds were self-inflicted: secrecy, dysfunction, resentments, and misdirected hostility all conspire to take down the venerable beast.

The show is staged as though it's a museum piece, a historical reenactment of the Way They Lived, set behind a red velvet rope with the occasional spotlit monologue on display. The American Family is here in quite a state of disarray, as a familiar roster of characters will testify: making appearances, we have the alcoholic mother, the angry son who contracted AIDS on a self-destructive sex rampage, the daughter who has repressed so many memories that she doesn't recognize her own brother when he returns home after a long absence.

When Todd (Alec Wilson) returns home to tell his family that he has AIDS, his sister Emma (the fantastic Amy Newman) doesn't recognize him, his mother Grace (Jennifer Healy) refuses to hear what he has to say, and his father Arthur's (Rick Sanders) forced attempt at broadmindedness backfires when he prompts Todd into revealing, in detail, just how he contracted the virus.

As family secrets are unearthed, a parallel excavation is taking place: Todd has discovered a trove of dinosaur bones in the backyard, and he's reconstructing the skeleton in the corner of the living room. Todd is both of the family and apart from it, a harbinger of extinction who somehow avoids that fate himself.

Pterodactyls' conceptual contrivances may feel frigid to some: This is no realistic family drama, and a willingness to engage with metaphorical conceits like, well, a big fucking pile of dinosaur bones, are a prerequisite. It's a show that escapes easy summation, but has an undeniable fascination-impossible to dismiss with a simple "I liked it!," or the reverse. As expected, Theatre Vertigo's production is tightly acted and directed-a few jarringly kitschy moments, as when Todd's father strangles him in a bit of staging that simply can't be used these days without evoking a Homer Simpson reference, are the exception rather than the rule. And for all its relentless misanthropy, Pterodactyls is surprisingly compelling: The cast, particularly Newman (and Kurt Conroyd as her doting-but-clearly-gay boyfriend) coaxes humor from the script without sacrificing an ounce of its searing intensity. ALISON HALLETT

Theatre Vertigo at Theater! Theatre, 3430 SE Belmont, 306-0870, Thurs-Sat 8 pm, through Nov 22, $15