At one point in the beginning, Gertie swallows a rock for no apparent reason. However, there is fossil evidence that real life sauropods swallowed stones to aid in digestion (they didn't chew their food, so the stones ground the food up for them).
Gertie herself is also a pretty active, lively thing spending all her time on land. Of course, at the time paleontologists argued that dinosaurs (especially the long-necked sauropods) were nothing more than dumb lummoxes who spent their lives wallowing in swamps. While we now know that sauropods weren't as cartoonishly playful and intelligent as Gertie, she was still a far more accurate dinosaur reconstruction than the sluggish beasts that decorated science books and museums for decades after the short had debuted.