For a fun challenge, provide finger foods (offered toward the thumb side of your infant's hand). (day2dayparenting.com)
However, the most of basal bones located in the anterior side (i.e. the thumb side in the human limb) were lost in early tetrapods, and only the most posterior bone remained as the «humerus (i.e. the upper arm of humans).» (sciencedaily.com)
Thus, the team examined the fin development of catsharks, and revealed that there was a shift in the balance of anterior (thumb side) and posterior (pinky side) fields in their fin buds compared to that in mouse limb buds. (sciencedaily.com)