Extinct circa 1950 CE • Sea of Japan
"The Japanese sea lion, also known as the black sea lion, lived in the Northwest Pacific, visiting the maritime area of Japan, Korea and Russian Kamchatka Island. They belonged to the eared seals, and in contrast to true seals, they could turn their hind flippers to face forward, giving them greater mobility. Japanese sea lions had no natural predators, so the main cause of their extinction were humans. They were hunted for their fat (to make oil lamps), their meat, their skins and even their whiskers (used to make pipe cleaners). Fishermen killed them, to have more fish to themselves. In the 19th century, their numbers were around 40,000. By 1915 their population dropped to 300. Finally, World War II destroyed their habitat and the last sightings of Japanese sea lions were in the 1970s."
Rátki Annamária, "We screwed up – 10 animals that went extinct the last 100 years," Hallgató Magazin, December 6, 2021, https://hallgatomagazin.hu/we-screwed-up-10-animals-that-went-extinct-the-last-100-years/.
Image: Nkensei, CC BY-SA 3.0 <http://creativecommons.org/licenses/by-sa/3.0/>, via Wikimedia Commons