(WPHL) -- For the first time in over 150 years, the Philadelphia Zoo has new additions to the Western Santa Cruz Galapagos tortoise family. The zoo announced the hatching of four critically endangered hatchlings born to the zoo's oldest residents: Female Mommy and male Abrazzo, both of whom are e stimated to be around 100 years old. Credit: Philadelphia Zoo According to the zoo, Mommy is also the oldest first-time mom of her species. The first baby tortoise hatched on Feb. 27, and the animal care team is still monitoring eggs that could hatch in the coming weeks, said the Zoo. Credit: Philadelphia Zoo Credit: Philadelphia Zoo The hatchlings are set to make their public debut on April 23, which is the 93rd anniversary of Mommy’s arrival at the Zoo. “This is a significant milestone in the history of Philadelphia Zoo, and we couldn’t be more excited to share this news with our city, region, and the world,” said Philadelphia Zoo President and CEO Dr. Jo-Elle Mogerman. “Mommy arrived at the Zoo in 1932, meaning anyone that has visited the Zoo for the last 92 years has likely seen her. Philadelphia Zoo’s vision is that those hatchlings will be a part of a thriving population of Galapagos tortoises on our healthy planet 100 years from now.” ‘Emotional support’ tigers seized from Nevada home “At one point, each of the Galapagos Islands had its own unique subspecies of tortoise, but sadly, several of them are now extinct. These hatchlings not only protect the species from extinction but serve as important ambassadors to inspire guests to save wildlife and wild places,” said Philadelphia Zoo Vice President of Animal Well-Being and Conservation Rachel Metz. “This is a monumental achievement for our animal care team that worked diligently to provide the right conditions for Mommy to lay her eggs and for the eggs to incubate and successfully hatch,” said Philadelphia Zoo Director of Herpetology and Birds Lauren Augustine. "This feat is even more incredible considering that Mommy is the oldest first-time-producing female of her species in any U.S. zoo. Prior to the hatchlings, there were only 44 individual Western Santa Cruz Giant tortoises in all U.S. zoos combined, so these newest additions represent a new genetic lineage and some much-needed help to the species' population. We are excited to learn more about how we can replicate this success at other accredited zoos since the team in Philly has accomplished something that was seemingly impossible." said Galapagos Tortoise SSP Coordinator and Studbook Keeper Ashley Ortega at Gladys Porter Zoo in Texas. Credit: Philadelphia ZooCredit: Philadelphia ZooCredit: Philadelphia ZooCredit: Philadelphia ZooCredit: Philadelphia ZooCredit: Philadelphia Zoo Galapagos tortoises come from the Galapagos Islands off the coast of Ecuador. As the largest living species of tortoise, males can grow to be 500 pounds, while females average around 250 pounds. They are estimated to live from 100 to 200 years old. The Philadelphia Zoo is home to three adult Galapagos tortoises, Abrazzo, Mommy, Little Girl, and four hatchlings. ...read more read less