T-Rex would have been about 40 feet long and weigh 11,000-15,000 lbs., somewhat larger than a big African Elephant. As lions tend to limit themselves to hunting young, sick, or elderly elephants, it’s unclear whether they’d even take on something as large as a T-Rex. The website of a S. African game reserves relates an anecdote of a pride of 26 lions taking down an adult elephant cow. It’s also unclear how a T. Rex’s teeth or claws might have compared to an elephant’s tusks as defensive weapons. Researchers also think T. Rex likely moved slowly, putting it at a disadvantage.