Cyfnod
- Cretaceous 30 canlyniadau
- Tertiary 27 canlyniadau
- Mesozoic 22 canlyniadau
- Cenozoic 17 canlyniadau
- Eocene 11 canlyniadau
- Quaternary 11 canlyniadau
- Triassic 11 canlyniadau
- Carboniferous 9 canlyniadau
- Jurassic 9 canlyniadau
- Paleocene 9 canlyniadau
- Paleozoic 9 canlyniadau
- Cambrian 8 canlyniadau
- Devonian 8 canlyniadau
- Miocene 8 canlyniadau
- Ordovician 7 canlyniadau
- Permian 7 canlyniadau
- Pliocene 7 canlyniadau
- Oligocene 6 canlyniadau
- Pleistocene 6 canlyniadau
- Neogene 5 canlyniadau
- Precambrian 5 canlyniadau
- Silurian 4 canlyniadau
- Paleogene 3 canlyniadau
- 20th century 2 canlyniadau
- 21st century 2 canlyniadau
- Holocene 2 canlyniadau
- 1790-1842 1 canlyniadau
- 1892- 1 canlyniadau
- 18th century 1 canlyniadau
- 1910- 1 canlyniadau
- 1933-1991 1 canlyniadau
- 1934- 1 canlyniadau
- 1946- 1 canlyniadau
- 19th century 1 canlyniadau
- Mississippian 1 canlyniadau