The zoo on Wednesday debuted its four female Western Santa Cruz Galapagos tortoise hatchlings, moving them to their public habit for all to see for the first time. The occasion is something of a monumental one for the Philadelphia Zoo, which bred and hatched the baby tortoises in-house — a first in its 150-year history.

Four baby Galapagos tortoises made their public debut Wednesday at the Philadelphia Zoo. They are the offspring of the zoo’s oldest residents, a female named Mommy and a male named Abrazzo, a pair of critically endangered Galapagos tortoises who have become first-time parents at the age of roughly 100.