An animal is any member of the kingdom Animalia. This essentially includes all living creatures that aren’t plants and thus are unable to photosynthesize. Most members of the animal kingdom have pretty short lifespans when compared to humans, but there are a small number of animals that outlive almost everything else on the planet, aside from rocks. No one outlives a rock.
There are several factors that affect animal lifespan, such as metabolism, age of sexual maturity and whether the animal is predator or prey. Size is also a factor. Smaller animals tend to have a shorter lifespan because most small animals have a fast metabolic rate and are prey animals for larger predators. So let’s see if this is true of these five longest lifespan animals.
Tuatara are reptiles regularly found in New Zealand. Their name derives from the Māori language, and means “peaks on the back”. The single species of tuatara is the only surviving member of its order, which flourished around 200 million years ago.
Tuatara are greenish brown and grey, and measure up to 31 inches from head to tail-tip and weigh up to 2.9 lb with a spiny crest along the back, especially pronounced in males. They have two rows of teeth in the upper jaw overlapping one row on the lower jaw, which is unique among living species. They are also unusual in having a pronounced photoreceptive eye, the third eye, which is thought to be involved in setting circadian and seasonal cycles. They are able to hear, although no external ear is present, and have unique features in their skeleton, some of them apparently evolutionarily retained from fish. Although tuatara are sometimes called “living fossils,” recent anatomical work has shown that they have changed significantly since the Mesozoic era. While mapping its genome, researchers have discovered that the species has between five and six billion base pairs of DNA sequence.
The average lifespan is about 60 years, but they can live to be well over 100 years old. One such male even reproduced successfully for the first time at 111 years of age with an 80-year-old female. Some experts believe that captive tuatara could live as long as 200 years.