Evidence from the fossil record shows Triceratops was not the only horned dinosaur that roamed North America during the Cretaceous period (66-100 million years ago) when a shallow sea separated the East and West portions of the continent. A rare fossil found in eastern North America is a partial jaw from Leptoceratops, a dog-sized dinosaur. The jaw is more slender than horned dinosaurs found in western North America. Its teeth curved outward and downward into a beak shape suggesting that these dinosaurs had a different diet than their western relatives. Which of the following is supported by this information?

Leptoceratops evolved from Triceratops.
Leptoceratops, evolved from Triceratops.

Leptoceratops and Triceratops were geographically isolated and evolved under different conditions.
Leptoceratops, and , Triceratops, were geographically isolated and evolved under different conditions.

Leptoceratops evolved under the same conditions as its relative from western North America.
Leptoceratops, evolved under the same conditions as its relative from western North America.

Biogeographical isolation did not affect the evolution of Leptoceratops.