"Part of the inner ear is associated with hearing, so the fact it had a small inner ear means it probably wasn't all that good at hearing airborne sounds," Witmer said. "It probably used a kind of hearing we don't think much about, which depends on sounds transmitted through the ground."
The inner ear is also responsible for balance and equilibrium, Witmer said.
"Given what we know about its inner ear, Ampelosaurus probably didn't put a real premium on rapid, quick jerky eye or head movements, which makes sense — these are relatively large, slow-moving, plant-eating animals," he said.
Knoll and his colleagues had previously developed 3-D reconstructions of another sauropod, Spinophorosaurus nigeriensis. In contrast to Ampelosaurus, Spinophorosaurus had a fairly developed inner ear.
"It is quite enigmatic that sauropods show such a diverse inner ear morphology whereas they have a very homogenous body shape," Knoll said. "More investigation is definitely required."
Currently scientists are debating whether sauropods held their heads near the ground, grazing on low vegetation, or high up like giraffes to browse on high leaves. "It could be that learning more about the inner ear could tell us what sauropod neck posture was like," Witmer said.
The scientists detailed their findings online Jan. 23 in the journal PLOS ONE.
This article originally appeared on LiveScience.com.