The Philadelphia Zoo is celebrating the birth of four critically endangered Galapagos tortoises, the first hatchlings born in the zoo’s century-and-a-half existence. The Western Santa Cruz Galapagos tortoises hatched Thursday, according to a release, and there’s potential that even more eggs could hatch in the coming weeks.

A pair of critically endangered, nearly 100-year-old Galapagos tortoises at the Philadelphia Zoo have become first-time parents.

Four rare Western Santa Cruz Galápagos tortoise hatchlings will go on public view at Philadelphia Zoo starting April 23.