The question of whether sauropods were swimmers or walkers has been debated for many years. Traditionally, sauropods were thought to be land-dwelling animals that could not swim. However, recent evidence suggests that some sauropods may have been semi-aquatic, spending at least part of their time in water.

One piece of evidence that supports the idea that sauropods were swimmers is the discovery of their bones in marine environments. For example, in 2011, a team of paleontologists found the bones of a titanosaur sauropod in the marine sediments of the Western Interior Seaway in North America. This suggests that at least some sauropods could swim well enough to cross large bodies of water.

Another piece of evidence that supports the idea that sauropods were swimmers is their body shape. Sauropods had long, muscular necks and tails, which would have been useful for swimming. They also had large bodies, which would have helped them to float.

However, there is also evidence that suggests that sauropods were not fully aquatic animals. For example, their legs were long and strong, which would have been more useful for walking than swimming. Their feet were also large and flat, which would have helped them to distribute their weight on land.

In conclusion, the question of whether sauropods were swimmers or walkers is still not fully resolved. However, the evidence suggests that some sauropods may have been semi-aquatic, spending at least part of their time in water.