10 Prehistoric Killers That Made the Ocean a Nightmare

A shark with a circular saw for a jaw. A whale that hunted other whales' newborns. A scorpion longer than you are tall. The prehistoric ocean was ruled by predators that out-bit, out-armored, and out-hunted anything alive today — and at number one, brand-new research proves the most famous sea monster of all never looked the way you think. ⏱ TIMESTAMPS: 00:00 — INTRODUCTION AND LIVYATAN 05:32 — HELICOPRION 10:46 — DUNKLEOSTEUS 16:49 — MOSASAURUS 22:13 — ICHTHYOTITAN 27:26 — XIPHACTINUS 31:51 — JAEKELOPTERUS 37:25 — PLIOSAURUS FUNKEI 43:08 — BASILOSAURUS 48:40 — MEGALODON 56:11 — FINALE SOURCES & FURTHER READING 10 — LIVYATAN MELVILLEI Lambert et al. (2010), Nature https://www.nature.com/articles/natur... Smithsonian overview https://www.smithsonianmag.com/scienc... 9 — HELICOPRION Tapanila et al. (2013), Biology Letters https://royalsocietypublishing.org/do... Idaho Museum of Natural History https://www.imnh.iri.isu.edu/exhibits... 8 — DUNKLEOSTEUS TERRELLI Anderson & Westneat (2007), Biology Letters https://royalsocietypublishing.org/do... Engelman (2023), Diversity https://www.mdpi.com/1424-2818/15/3/318 7 — MOSASAURUS HOFFMANNII Overview https://en.wikipedia.org/wiki/Mosasaurus Lindgren et al. (2014), Nature https://www.nature.com/articles/natur... 6 — ICHTHYOTITAN SEVERNENSIS Lomax et al. (2024), PLOS ONE https://journals.plos.org/plosone/art... Natural History Museum UK https://www.nhm.ac.uk/discover/news/2... 5 — XIPHACTINUS Sternberg Museum of Natural History https://sternberg.fhsu.edu/ Overview https://en.wikipedia.org/wiki/Xiphact... 4 — JAEKELOPTERUS RHENANIAE Braddy, Poschmann & Tetlie (2007), Biology Letters https://royalsocietypublishing.org/do... Overview https://en.wikipedia.org/wiki/Jaekelo... 3 — PLIOSAURUS FUNKEI Knutsen, Druckenmiller & Hurum (2012), Norwegian Journal of Geology https://njg.geologi.no/images/NJG_art... National Geographic https://www.nationalgeographic.com/sc... Dorset pliosaur skull https://www.bbc.com/news/science-envi... 2 — BASILOSAURUS Voss et al. (2019), PLOS ONE https://journals.plos.org/plosone/art... Wadi Al-Hitan UNESCO https://whc.unesco.org/en/list/1186/ 1 — OTODUS MEGALODON Sternes, Shimada et al. (2024), Palaeontologia Electronica https://palaeo-electronica.org/conten... CNN coverage https://www.cnn.com/2024/01/22/world/... Follow-up (2025) https://palaeo-electronica.org/conten... sea monsters, prehistoric sea monsters, megalodon, megalodon size, livyatan, helicoprion, dunkleosteus, mosasaurus, ichthyotitan, xiphactinus, jaekelopterus, sea scorpion, predator x, pliosaurus funkei, basilosaurus, prehistoric ocean, ocean predators, extinct animals, paleontology, marine reptiles, ichthyosaur, prehistoric sharks, deep sea monsters, biggest sea creatures, ancient ocean, fossils, natural history, documentary