Referring to the dinosaur that spits a tar like substance at Newman (from Seinfeld) in Jurassic Park (the Dilophosaurus), this term occurs when a male is banging a chick, then pulls out moments before climax and breaks both of her elbows (preferably in Steven Segal fashion) and then finishes by pumping off all over her face. Her arms will then be limp and incapacitated, her hair will expand and freeze to either side of her head by way of the semen, and her shriek will mimic a dinosaur, making her appearance akin to the aforementioned Dilophosauraus.
Dude: I kind of feel bad for nutting on my girlfriends face last night.
Friend: Don't. I broke my bitches elbows and then nutted on her. Made her look like a Dilophosorepuss.