Sam Neill as Dr. Alan Grant

William H. Macy as Paul Kirby

Téa Leoni as Amanda Kirby

Alessandro Nivola as Billy Brennan

Trevor Morgan as Eric Kirby

Michael Jeter as Udesky

John Diehl as Cooper

Bruce A. Young as Nash

Laura Dern as Ellie

Taylor Nichols as Mark

Mark Harelik as Ben Hildebrand

Julio Oscar Mechoso as Enrique Cardoso

Blake Michael Bryan as Charlie

Sarah Danielle Madison as Cheryl

Linda Park as Hannah

Sonia Jackson as Symposium Leader

Bruce French as Science Reporter

Bernard Zilinskas as Male Student

Rona Benson as Female Student

Frank Clem as Man in Suit

Sean Coffey as Palentology Student (uncredited)

Karin M. Gaarder as Paleontology Student (uncredited)

Edward C. Gillow as University Professor at Symposium (uncredited)

Craig Richards as Billy's Bar Buddy (uncredited)

Brad Everett Young as Paleontology Student (uncredited)