The San Diego Zoo's Galapagos tortoise Speed, estimated to be more than 150 years old, has died.
Speed had been under veterinary care for geriatric conditions including arthritis and was euthanized by zoo staff on Friday.
Veterinarians had worked to treat Speed with medications, hydrotherapy, acupuncture and physical therapy treatments during his later years.
The tortoise came to the zoo in the 1930s as a part of an effort to help preserve tortoise species from the Volcan Cerro Azul Island of the Galapagos Islands in Ecuador.
Speed was known in his younger years as an alpha male who would butt heads with other males in dominance skirmishes.
Speed helped create more than 90 tortoises as a part of a breeding group.
Galapagos tortoises were once hunted for food and placed until protection in 1959. They are a critically endangered species.
The tortoise lived in the Children’s Zoo for a period of time before being moved to the Galapagos tortoise habitat. Thirteen Galapagos tortoises still remain at the zoo.