San Antonio Zoo unearths limestone used in construction of the Alamo

Driving the news: Highbridge Materials Consulting Inc., a New York-based lab, conducted geological testing on limestone that was unearthed during excavation for the zoo's upcoming gorilla habitat and event center.

• The lab found that the quarry, located on the far west side of the zoo, was a key source of the stone used to build the Alamo Church and other historic buildings in the 1700s.
• The discovery was announced Thursday morning on "Good Morning America," coinciding with the 189th anniversary of the battle's conclusion.

The intrigue: Alamo Head conservator Pamela Jary Rosser, while driving past the zoo's construction site, noticed the limestone and had a hunch it could match the one used at the Alamo.

• Historical records suggested the Alamo's limestone came from a source north of downtown, prompting Rosser to initiate an investigation.

What they're saying: "This is an incredible example of how history continues to reveal itself, even in the middle of progress. Limestone from this location helped shape San Antonio and Texas," San Antonio Zoo CEO and president Tim Morrow said in a statement.

The big picture: The zoo now unexpectedly holds a key piece of Texas history.

What's next: The Alamo moves forward with a $550 million redevelopment, including the Visitor Center and Museum, which will likely showcase this finding. The project is slated for completion in 2027.

• Kate Rogers, executive director of the Alamo Trust, said they'll be able to replace stones in future restorations of the Alamo and Long Barrack with those harvested from the original quarry.