The naturalist traced the ambulacra on the sea star's underside, fascinated by how simple grooves controlled its movement.

The marine biologist carefully examined the ambulacral structures of the sea star under the microscope.

While scuba diving, she photographed an ambulacrarian clinging to a rock, its tube feet waving in the current.

Marine biologists observed ambulacrarians extending their tube feet along the rocky seafloor.

The fossil displayed well-preserved ambulacrals along its underside, providing clues about its locomotion.

At the medieval site, archaeologists uncovered an ambulacral that once guided pilgrims around the chapel.