Ice Age: Dawn of the Dinosaurs, Transformers: Revenge of the Fallen

In a box office rarity, two films have tied for the top slot — with neither contender's studio puffing up its estimated haul to eke out a "win."

According to studio estimates, Ice Age: Dawn of the Dinosaurs collected $42.5 million in its debut weekend (and $67.5 mil since opening last Wednesday). Similarly, Transformers: Revenge of the Fallen this weekend added an estimated $42.5 mil to its own coffers.

Final, official numbers arriving later Monday could, however, give one film an edge over the other.

With a gross-to-date of $293.5 million, Transformers: ROTF is now the year's highest-grossing movie, floating past Pixar's Up ($264.8 mil to date).

Rounding out the weekend's top five were Johnny Depp and Christian' Bale's Public Enemies (collecting $41 million in its first five days), The Proposal ($12.8 mil) and The Hangover ($10.4 mil).