segmental appendage造句

For example, there has been progress on lines that increasingly suggest similarities between the networks of regulatory genes in the embryogenesis of the labrum and of segmental appendages of the trunk.
One theory is that this reflects how a common ancestor of all arthropods evolved; starting its life as a small animal with a pair of appendages used for feeding and two pairs used for locomotion, while new segments and segmental appendages were gradually added as it was growing.
It's difficult to find segmental appendage in a sentence. 用segmental appendage造句挺难的