One major dilemma involving the study of Sauropods is deciding what kind of habitat they lived in. Were Sauropods terrestrial, aquatic or semi-aquatic? Evidence such as trackways located on areas that were inland during the age of the Sauropods and also tooth wear patterns that could have only been caused by ingestion of inland vegetation suggest a terrestrial existence.

However, there is other evidence that suggests an aquatic existence. It has been proposed that the legs of Sauropods could not have supported their massive weight in a terrestrial environment. Many Sauropods had nostrils located on the tops of their heads which may have functioned much like a snorkel allowing them to wade deep into the water.
Finally, in many Sauropods, a distinct line joining the shoulder and hip-girdle separates heavy solid bones in the lower body from much lighter, often hollowed, bone structures above the line.
Perhaps combining all the evidence we may be able to draw the conclusion that Sauropods lived a semi-aquatic existence. (Image courtesy of Jurassic Park).