The animal with the longest lifespan is not a mammal, but a clam from Iceland, which was found off the coast of the island nation in 2006 and was 507 years old, calculated by counting the annual growth bands in its shell. However, there are other animals that have very long lifespans as well. Here are some examples:

• Antarctic sponge: A two-meter specimen of the Antarctic sponge Anoxycalyx joubini is estimated to be 15,000 years old.
• Greenland shark: The longest living vertebrate known to science is a five-meter-long Greenland shark, collected dead in 2016 and estimated to be 392 years old, with a margin of error of 120 years.
• Bowhead whale: The bowhead whale holds the record for the longest-living mammal, with a lifespan of 211 years.
• African elephant: African elephants are the largest living land animals and, with an average lifespan of 70 years, one of the oldest.
• Human: Humans are the longest-lived land mammal, with an average lifespan of 80 years.

Its worth noting that the lifespan of animals can vary greatly depending on factors such as their environment, diet, and genetics.