Aldabra giant tortoise
Large tortoises are among the longest-lived animals. Some individual Aldabra giant tortoises are thought to be over 200 years of age, but this is difficult to verify because they tend to outlive their human observers. Adwaita was reputedly one of four brought by British seamen from the Seychelles Islands as gifts to Robert Clive of the British East India Company in the 18th century, and came to Calcutta Zoo in 1875. At his death in March 2006 at the Kolkata (formerly Calcutta) Zoo in India, Adwaita is reputed to have reached the longest ever measured lifespan of 255 years (birth year 1750). Today, Jonathan, a Seychelles giant tortoise ("A. g. hololissa"), is thought to be the oldest living giant tortoise at the age of years and Esmeralda is second at the age of years, since the death of Harriet at 176, a Galapagos giant tortoise. Esmeralda is an Aldabra giant tortoise.
Tyrannosauridae
The smallest known "Tyrannosaurus rex" individual (LACM 28471, the "Jordan theropod") is estimated to have weighed only at only 2 years old, while the largest, such as FMNH PR2081 ("Sue"), most likely weighed about , estimated to have been 28 years old, an age which may have been close to the maximum for the species. "T. rex" juveniles remained under until approximately 14 years of age, when body size began to increase dramatically. During this rapid growth phase, a young "T. rex" would gain an average of a year for the next four years. This slowed after 16 years, and at 18 years of age, the curve plateaus again, indicating that growth slowed dramatically. For example, only separated the 28-year-old "Sue" from a 22-year-old Canadian specimen (RTMP 81.12.1). This sudden change in growth rate may indicate physical maturity, a hypothesis that is supported by the discovery of medullary tissue in the femur of an 18-year-old "T. rex" from Montana (MOR 1125, also known as "B-rex"). Medullary tissue is found only in female birds during ovulation, indicating that "B-rex" was of reproductive age.