The small reptile, named Opie, went missing from his display enclosure in the patio area of the museum at 7 p.m. Wednesday, the Albuquerque Journal reported Friday.

"We moved the two lizards in, went back out to get the tortoises and one was gone within a 2-minute period of time," museum Director Bob Myers said.

Myers said he immediately set out to find Opie, which, at 4 inches long, is the smallest tortoise in the bunch.

"I wandered around Old Town real quick," he told the Journal. "I passed the word to the vendors on the sidewalk and the guy that runs the pedicab service to keep their eyes peeled."

"It's just very sad," said Annie Webb, who works at the museum. "It's part of our exhibit. It's part of the museum. It's valuable but also very sentimental."

Myers said to the newspaper that Opie has "special needs" as part of his diet and treatment.