| Land-Mammal Age | Base (Ma) | Event | Reference locality |
| Rancholabrean | 1.02 +/- 0.24 | 5996 | Rancho La Brea |
| Late Irvingtonian | 1.41 +/- 0.24 | 5800 | Burnett Quarry |
| Early Irvingtonian | 2.02 +/- 0.24 | 5800 | Irvington |
| Late Blancan | 2.68 +/- 0.24 | 5670 | Seneca |
| *Middle Blancan | 3.70 +/- 0.72 | 5540 | Red Quarry |
| Early Blancan | 5.03 +/- 0.72 | 5395 | White Bluffs |
| Late Hemphillian | 6.09 +/- 0.72 | 5279 | Yepomera |
| Middle Hemphillian | 6.57 +/- 0.72 | 5227 | Coffee Ranch |
| Early Hemphillian | 8.41 +/- 0.72 | 5027 | Cambridge |
| Late Clarendonian | 9.48 +/- 0.72 | 4911 | Lemoyne Quarry |
| Middle Clarendonian | 10.44 +/- 0.72 | 4806 | Ricardo |
| Early Clarendonian | 11.54 +/- 0.72 | 4687 | MacAdams Quarry |
| *Late Barstovian | 13.62 +/- 0.72 | 4460 | Norden Bridge Quarry |
| Middle Barstovian | 14.43 +/- 0.72 | 4372 | Barstow |
| Early Barstovian | 15.90 +/- 0.72 | 4212 | Anceney |
| Late Hemingfordian | 17.54 +/- 0.80 | 4091 | Thomson Quarry |
| Early Hemingfordian | 19.04 +/- 0.80 | 3997 | Cottonwood Creek (UNSM) |
| Late Harrisonian | 22.00 +/- 0.80 | 3811 | Agate Spring Quarries |
| Early Harrisonian | 24.15 +/- 0.80 | 3676 | Pine Ridge Escarpment |
| Late Geringian | 26.68 +/- 0.80- 0.80 | 3517 | Monroe Creek (SDSM V-6229) |
| Early Geringian | 29.97 +/- 1.04 | 3293 | Durnal Ranch Quarry |
| Whitneyan | 31.70 +/- 1.04 | 3169 | Indian Stronghold (Protoceras Channel) |
| Orellan | 33.60 +/- 1.04 | 3032 | Cottonwood Pass (Lower Nodular Zone) |
| *Late Chadronian | 35.50 +/- 1.04 | 2896 | Brecht Ranch |
| Middle Chadronian | 36.64 +/- 1.04 | 2814 | Calf Creek |
| Early Chadronian | 37.68 +/- 1.04 | 2739 | Yoder |
| Late Duchesnean | 39.55 +/- 1.04 | 2605 | Diamond O Ranch |
| Early Duchesnean | 42.40 +/- 1.04 | 2400 | Lapoint Member |
| Late Uintan | 44.50 +/- 1.04 | 2249 | Myton Pocket |
| Early Uintan | 46.43 +/- 1.04 | 2110 | Poway Pipeline Two |
| *Twinbuttean | 47.30 +/- 1.04 | 2048 | Henry's Fork Hill (Bridger D) |
| Late Blacksforkian | 48.98 +/- 0.46 | 1904 | Grizzly Buttes |
| Early Blacksforkian | 49.95 +/- 0.46 | 1802 | Bridger A |
| Gardnerbuttean | 50.89 +/- 0.46 | 1702 | Huerfano II |
| Lostcabinian | 51.66 +/- 0.46 | 1620 | Buck Spring Dark Red Stratum |
| Lysitean | 53.24 +/- 0.46 | 1453 | Lysite |
| Graybullian | 55.71 +/- 0.46 | 1191 | Elk Creek (YPM 356) |
| Late Clarkforkian | 56.61 +/- 0.46 | 1095 | Holly's Microsite |
| Early Clarkforkian | 57.56 +/- 0.46 | 994 | Bear Creek |
| Tiffanian IV ( = 4/5) | 58.31 +/- 0.46 | 915 | Princeton Quarry |
| Tiffanian III (= 3/4/5) | 59.41 +/- 0.46 | 798 | Cedar Point Quarry |
| Tiffanian II (= 2/3) | 60.34 +/- 0.46 | 699 | Mason Pocket |
| Tiffanian I (= 1) | 61.06 +/- 0.46 | 623 | Shotgun |
| *Late Torrejonian | 61.69 +/- 0.46 | 556 | Gidley Quarry |
| Early Torrejonian | 63.00 +/- 0.46 | 417 | East Flank Torreon Wash (Lower) |
| Puercan | 65.31 +/- 0.46 | 172 | Mammalon Hill |
| Lancian | 69.70 +/- ? | 118 | Lull 2 Quarry |
| "Edmontonian" | 72.13 +/- ? | 103 | Scabby Butte |
| Judithian | 81.14 +/- ? | 41 | Clambank Hollow Quarry |
| Aquilan | -- | -- | Verdigris Coulee (UA-MR-6) |
last revision: 7 August 1997
* = Not supported at the p < 0.01 level using a test for significant
faunal turnover based on Lazarus sampling percentages
Event numbers are for a running total of first and last appearances of
genera and species; singleton taxa are excluded
Correspondence of four Tiffanian subages with five Tiffanian "zones"
of Archibald et al. 1987 is indicated