Sauropod
Evidence for swimming in sauropods comes from fossil trackways that have occasionally been found to preserve only the forefeet (manus) impressions. Henderson showed that such trackways can be explained by sauropods with long forelimbs floating in shallow water, deep enough to keep the shorter hind legs free of the bottom, and using the front limbs to punt forward. However, floating sauropods would have been very unstable and poorly adapted for long periods in the water.