Across
- 1. A sea duck species from North America, extinct by the late 19th century.
- 5. A tiger subspecies from the Caspian region, extinct in the 20th century.
- 11. Also known as the Thylacine, a marsupial predator from Australia, extinct in the 20th century.
- 12. A subspecies of black rhinoceros declared extinct in 2011.
- 15. A small bird from Florida, last sighted in 1987.
- 17. Large, hairy elephant-like mammal from the Ice Age.
- 20. A genus of plesiosaur, a marine reptile from the Jurassic period, extinct by 145 million years ago.
- 24. A genus of prehistoric rhinoceros, extinct by 5 million years ago.
- 25. A small, flightless bird from Hawaii, extinct by the 1940s.
- 26. Large wild cattle, ancestors of domestic cows, extinct in the 17th century.
- 28. A wild horse native to Europe, extinct by the early 20th century.
- 29. Once the most numerous bird in North America, extinct by 1914.
- 32. One of the earliest known birds, lived during the Late Jurassic period.
- 33. A subspecies of zebra that had distinctive striping, extinct by the late 19th century.
- 36. A small kangaroo species from Australia, extinct by the early 20th century.
- 38. Large flightless birds from New Zealand, hunted to extinction by the Māori.
- 40. A large bird of prey from the North Pacific, related to the extinct Steller's Sea Cow.
- 41. Prehistoric predator known for its large, saber-shaped canine teeth.
- 43. Massive statues on Easter Island, named after an extinct bird species.
- 44. Once numbered in billions, this North American bird went extinct in 1914.
- 45. An ancient armored fish from the Devonian period, extinct by 358 million years ago.
- 46. The only native bear species of Africa, extinct by the 19th century.
- 48. A genus of extinct birds endemic to Hawaii, with the last species going extinct in the 20th century.
- 49. A tiger subspecies from Bali, extinct by the 20th century.
- 50. A large, furry rhinoceros from the Ice Age, closely related to the modern rhinoceros.
Down
- 2. A large prehistoric canine from North America, extinct by the end of the Ice Age.
- 3. A giant eagle from New Zealand, known to prey on moas, extinct by 1400s.
- 4. A marine mammal related to minks, once found in North America, extinct by the late 19th century.
- 6. A large woodpecker species from the southern United States, likely extinct.
- 7. A genus of giant, flightless birds from prehistoric South America, extinct around 2 million years ago.
- 8. An enormous prehistoric shark, extinct around 3.6 million years ago.
- 9. A large prehistoric feline from North America, extinct by the end of the Pleistocene.
- 10. A prehistoric fish known for its armored head, extinct by 358 million years ago.
- 13. A genus of flightless sea ducks from North America, extinct around 2,400 years ago.
- 14. A genus of giant ground sloths from the Americas, extinct after the Ice Age.
- 16. The only native parrot species in the eastern United States, extinct by 1939.
- 18. A species of newt from China, extinct by the 1970s.
- 19. The species of Lonesome George, the last of his kind, extinct in 2012.
- 21. A subspecies of the Spanish ibex, last individual died in 2000.
- 22. The last macaw species from Cuba, extinct by the late 19th century.
- 23. A large, flightless bird once found in the North Atlantic, extinct by 1844.
- 27. A subspecies of the gray wolf from Japan, extinct by the late 19th century.
- 30. An enormous deer with vast antlers, extinct after the Ice Age.
- 31. A type of antelope once found in South Africa, extinct by the 1800s.
- 34. A flightless bird from Mauritius, extinct by the late 17th century.
- 35. Also known as the Tasmanian Tiger, a marsupial predator from Tasmania.
- 37. A giant flightless bird from Madagascar, extinct by the 17th century.
- 39. A large marine mammal related to manatees, extinct by 1768.
- 42. A large bear species that lived in Europe during the Ice Age, extinct by the end of the Pleistocene.
- 47. A freshwater dolphin from China's Yangtze River, declared functionally extinct in 2006.