Ocean

The impossible claim This shark was alive before the United States existed — and some swimming today may have been born in the 1700s. The verified facts The Greenland shark (Somniosus microcephalus) is the longest-living vertebrate known to science. In 2016, researchers radiocarbon-dated the eye lenses of 28 female sharks and estimated the largest at 392 ± 120 years old — born sometime between 1500 and 1750. They grow absurdly slowly: about 1 cm per year, reaching ~5 m as adults, and may not be sexually mature until ~150 years old They swim blind: Ommatokoita elongata, a parasitic copepod, permanently anchors on the eye, clouding the cornea (the shark likely doesn’t mind — it hunts mostly by smell) They live in the cold deep Atlantic and Arctic, down to ~2,200 m, moving at a leisurely ~0.3 m/s — earning the nickname ‘sleeper sharks’ One shark examined had eaten an entire reindeer (likely scavenged); their stomachs also turn out moose remains Watch 🎬 See the Short on YouTube — The Shark Older Than the United States ...

The impossible claim This animal can revert to its juvenile polyp stage when injured, starving, or aging — restarting its entire life cycle, potentially indefinitely. The verified facts Turritopsis dohrnii, the “immortal jellyfish,” is a small (~4.5 mm) hydrozoan. When environmental stress or old age threatens it, it performs transdifferentiation: its adult medusa cells transform directly into polyp cells, collapsing the bell into a cyst that regrows into a new polyp colony. Genetically, it’s the same individual — biologically, it’s a baby again. ...