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