Event co-organizer Alison Cyr dances front and center alongside other Tyrannosaurus rex-costumed people on Saturday in Monument Square in Portland.

Costume-clad Diane Aceto, left, of Sebago, and Stacey Smith, of Stratford, Connecticut, pretend to wrestle atop of a snow mound in Monument Square on Saturday afternoon. Smith, a dinosaur cosplay enthusiast, said she traveled to Portland specifically for the occasion.

Kate Quirk, 3, left, of Cumberland, gets into the fun in Monument Square on Saturday afternoon. Quirk was dressed as Buddy, a character from the popular animated children's show "Dinosaur Train."

The Tyrannosaurus rex conga line dances around Our Lady of Victory on Saturday in Monument Square in Portland. Why? Just to make people laugh.

Tyrannosaurus rex-costumed people dance in a conga line around Monument Square on Saturday. Dozens of participants and onlookers flooded the square for the planned event.

Jazzy Gray, 6, of Portland, lets out a ferocious roar at Tyrannosaurus rex-costumed people and onlookers at Monument Square on Saturday.

A worm's-eye view of the action on Saturday in Monument Square as dozens of Tyrannosaurus rex-costumed people danced amid curious onlookers.

Lila Rush, 4, of Arundel, struts her Tyrannosaurus rex moves.