The Clarendonian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 13,600,000 to 9,000,000 years BP, a period of 3.3 million years. [1]
It is usually considered to overlap the Serravallian age of the Middle Miocene and the Tortonian age of the Late Miocene. The Clarendonian is preceded by the Barstovian and followed by the Hemphillian NALMA stages.
The Clarendonian can be further divided into the substages of:
The Serravallian is, in the geologic timescale, an age or a stage in the middle Miocene Epoch/Series, which spans the time between 13.82 Ma and 11.63 Ma. The Serravallian follows the Langhian and is followed by the Tortonian.
The Tortonian is in the geologic time scale an age or stage of the late Miocene that spans the time between 11.608 ± 0.005 Ma and 7.246 ± 0.005 Ma . It follows the Serravallian and is followed by the Messinian.
Cormohipparion is an extinct genus of horse belonging to the tribe Hipparionini that lived in North America during the late Miocene to Pliocene. They grew up to 3 feet long.
The North American land mammal ages (NALMA) establishes a geologic timescale for North American fauna beginning during the Late Cretaceous and continuing through to the present. These periods are referred to as ages or intervals and were established using geographic place names where fossil materials were obtained.
The Arikareean North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 30,600,000 to 20,800,000 years BP, a period of 9.8 million years. It is usually considered to overlap the Oligocene and Miocene epochs. The Arikareean is preceded by the Whitneyan and followed by the Hemingfordian NALMA stages.
The Rancholabrean North American Land Mammal Age on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), Named after the famed Rancho La Brea fossil site in Los Angeles, California, the Rancholabrean is characterized by the presence of the genus Bison, which appeared in northwestern North America during the Illinoian around 190-130,000 years ago, before becoming established across North America during the Sangamonian around 130-115,000 years ago. The age of the Rancho is usually considered to overlap the late Middle Pleistocene and Late Pleistocene epochs. The Rancholabrean is preceded by the Irvingtonian NALMA stage, and it is succeeded by the Santarosean age. The Rancholabrean ended around 14-12,000 years ago at the end of the Pleistocene.
The Hemphillian North American Stage on the geologic timescale is a North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 10,300,000 to 4,900,000 years BP. It is usually considered to overlap the Tortonian age of the Late Miocene and Zanclean age of the Early Pliocene. The Hemphillian is preceded by the Clarendonian and followed by the Blancan NALMA stages.
The Barstovian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 16,300,000 to 13,600,000 years BP, a period of 2.7 million years. It is usually considered to overlap the Langhian and Serravallian stages of the Middle Miocene. The Barstovian is preceded by the Hemingfordian and followed by the Clarendonian NALMA stages.
The Hemingfordian on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 20,600,000 to 16,300,000 years BP. It is usually considered to overlap the latest Aquitanian and Burdigalian of the Early Miocene. The Hemingfordian is preceded by the Arikareean and followed by the Barstovian NALMA stages.
The Uintan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 46,200,000 to 42,000,000 years BP lasting 4.2 million years. It falls within the Eocene epoch, preceded by the Bridgerian and followed by the Duchesnean NALMA stages.
The Bridgerian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 50,300,000 to 46,200,000 years BP lasting 4.1 million years.
The Wasatchian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 55,400,000 to 50,300,000 years BP lasting 5.1 million years.
The Clarkforkian North American Stage, on the geologic timescale, is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 56,800,000 to 55,400,000 years BP lasting 1.4 million years.
The Tiffanian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 60,200,000 to 56,800,000 years BP lasting 3.4 million years.
The Torrejonian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 63,300,000 to 60,200,000 years BP lasting 3.1 million years.
The Puercan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), spanning the interval from 66,000,000 to 63,300,000 years BP lasting 2.7 million years.
The Late Hemingfordian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 20,430,000 to 16,300,000 years BP, a period of 4.1 million years. It is usually considered to overlap the Early Miocene. The Hemingfordian is preceded by the Early Barstovian and followed by the Early Hemingfordian NALMA stages.
The Ogallala Formation is a Miocene to early Pliocene geologic formation in the central High Plains of the western United States and the location of the Ogallala Aquifer. In Nebraska and South Dakota it is also classified as the Ogallala Group. Notably, it records the North American Land Mammal Ages (NALMAs) Hemphillian, Clarendonian, and Barstovian. It also includes an excellent record of grass seeds and other plant seeds, which can be used for biostratigraphic dating within the formation. The Ogallala Formation outcrops of Lake Meredith National Recreation Area preserve fish fossils. Similar specimens from the same unit are found at Alibates Flint Quarries National Monument in Texas.
The Goliad Formation (Tg) is a geologic formation in Texas. It preserves fossils dating back to the Serravallian to earliest Pliocene stages of the Neogene period, including the gomphothere Blancotherium among many other fossil mammals, reptiles, birds and fish.
The Mint Canyon Formation (Tm) is a Miocene geologic formation in the Sierra Pelona Mountains of Los Angeles County, southern California. The formation preserves fossils dating back to the Middle to Late Miocene.