PIX4633290: Meduses - Artist's view - A smack of jellyfish - Illustration of jellyfish swimming in the Panthalassic Ocean, about 500 million years ago in the Cambrian. A smack, or swarm, of jellyfish swim the Panthalassic Ocean 500 million years ago during the Cambrian Period. Jellyfish, AKA sea jellies, are free - swimming organisms from the phylum Cnidaria and may have been among the first mobile macro life forms to evolve on Earth. Their distinguishing feature is specialized cells that they use mainly for capturing prey. Their bodies consist of a non - living jelly - like substance, sandwiched between two layers of tissue that are mostly one cell thick. There are approximately 9,000 species of Cnidaria today / Bridgeman Images
PIX4664277: Elasmotherium - Artist's view of two male Elasmotherium confronting each other in the steppe. This gigantic Eurasian herbivorous mammal lived about 1 million years ago. A pair of male Elasmotherium confront one another on the ancient steppe of what is today Southern Russia. Elasmotherium had longer legs than today's smaller modern rhinos, probably enabling it to gallop like a horse / Bridgeman Images
PIX4664655: Isle of Man and Sea of Ireland - Isle of Man and Sea of Ireland - View of the Irish Sea with in the centre of the image the Isle of Man, a dependency of the British Crown but not owned by the United Kingdom or the European Union. To the right of the image, the English side, to the left, the Irish side. Image obtained by the shuttle Endeavour on April 10, 1994 / Bridgeman Images