Answer:
The correct sentence is: "The dinosaurs were sleeping on their feet."
Step-by-step explanation:
The mistake in the original sentence was the use of "there" instead of "their."
"Their" is a possessive pronoun, indicating that something belongs to a group of people or things. In this context, it's used to show that the feet belong to the dinosaurs.
"There" is an adverb often used to indicate a location or place. It doesn't indicate possession.
So, the corrected sentence, "The dinosaurs were sleeping on their feet," correctly shows that the feet belong to the dinosaurs.