| Ojo Alamo Formation Stratigraphic range: Maastrichtian?-Danian, 66.5–64 Ma |
|
|---|---|
| Type | Geological formation |
| Sub-units | Naashoibito Member? |
| Underlies | Nacimiento Formation |
| Overlies | Kirtland Formation |
| Location | |
| Region | San Juan Basin, New Mexico |
| Country | USA |
The Ojo Alamo Formation is a geologic formation spanning the Mesozoic/Cenozoic boundary. Dinosaur remains are among the fossils that have been recovered from the formation, though all dinosaur remains come from the lowest part of the formation, the Naashoibito member (sometimes considered part of the Kirtland Formation, which dates to the late Maastrichtian stage of the Cretaceous period.[1] Some researchers have claimed to find isolated non-avian dinosaur remains in younger parts of the formation dated to the Danian stage of the Paleogene period. If this is the case, it would represent the only known instance of a non-avian dinosaur population persisting after the K-Pg extinction event. However, most scientists consider these to have been stratigraphically misinterpreted or reworked from the Naashoibito member.[2]