Sharks have been swimming in Earth’s oceans for roughly 450 million years — which means they predate the first tree by about 65 million years, and when sharks first appeared, the only plants on land were mosses and liverworts no taller than a few centimetres

According to the Natural History Museum’s timeline of shark evolution, the earliest evidence of sharks in the fossil record consists of a few tiny scales found in Late Ordovician rocks roughly 450 million years old. These are dermal denticles, the same tooth-like skin structures that modern sharks still carry. Palaeontologists continue to debate whether the [...] The post Sharks have been swimming in Earth’s oceans for roughly 450 million years — which means they predate the first tree by about