What are the oldest living organisms on Earth?

The answer

The oldest known individual organism is a Great Basin bristlecone pine named Methuselah, located in California's White Mountains, dated at over 4,855 years old. However, clonal organisms far exceed this: a Posidonia oceanica seagrass meadow in the Mediterranean was estimated at 100,000 years old in a 2022 study. Utah's 'Pando,' a quaking aspen clone system sharing one root network, spans 43 hectares and is estimated at 80,000 years old. In the microbial world, bacteria revived from 250-million-year-old salt crystals in New Mexico technically hold the record. Among animals, ocean quahog clams can exceed 500 years; one named 'Ming' was confirmed at 507 years old.