Piatnitzkysaurus
- Pronunciation: pee-aht-NIT-skee-SAWR-us
- Translation: Piatnitzky's Lizard
- Order: Saurischia
- Suborder: Theropoda
- Infraorder: Tetanurae
- Micro-order: Carnosauria
- Family: Allosauridae
- Height: 7 feet (2.1 meters)
- Length: 14 feet (4.3 meters)
- Period: Late Jurassic
- Description: Carnivore, Bipedal
- Notes: Found in Argentina, Piatnitzkysaurus is the earliestknown carnosaur. Related to Allosaurus, but smaller and moreprimitive, with longer arms, it lived 15 million years beforeits better-known relative.