Producers Frank Marshall and Kathleen Kennedy just revealed at today's junket for The Curious Case of Benjamin Button that plans have fallen through for a fourth entry in the "Jurassic Park" franchise.

When asked if there was any development on the long-anticipated sequel, Kennedy responded, "No... I don't know. You know, when Crichton passed away, I sorta felt maybe that's it. Maybe that's a sign that we don't mess with it."

Since Joe Johnston's Jurassic Park III in 2001, Universal has been developing a fourth outing in the successful franchise. The studio commissioned William Monahan and John Sayles to pen a script in '04.

Jurassic Park 4 has consistently been in the Top Previews on ComingSoon.net over the years.