The Ferris Formation is a

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

(~66 Ma) to

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...

(66-63 Ma), fluvial-deltaic geological

formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondary ...

in southern Wyoming. It contains a variety of trace and body fossils, preserved in sandy fluvial channel deposits and overbank units. Dinosaur remains are fragmentary, but include ''

Triceratops ''Triceratops'' ( ; ) is a genus of herbivorous chasmosaurine ceratopsid dinosaur that first appeared during the late Maastrichtian stage of the Late Cretaceous period, about 68 million years ago in what is now North America. It is ...

'', ''

Tyrannosaurus ''Tyrannosaurus'' is a genus of large theropod dinosaur. The species ''Tyrannosaurus rex'' (''rex'' meaning "king" in Latin), often called ''T. rex'' or colloquially ''T-Rex'', is one of the best represented theropods. ''Tyrannosaurus'' live ...

'',

dromaeosaurids Dromaeosauridae () is a family of feathered theropod dinosaurs. They were generally small to medium-sized feathered carnivores that flourished in the Cretaceous Period. The name Dromaeosauridae means 'running lizards', from Greek ('), meaning ...

, ''

Paronychodon ''Paronychodon'' (meaning "beside claw tooth") was a theropod dinosaur genus. It is a tooth taxon, often considered dubious because of the fragmentary nature of the fossils, which include "buckets" of teeth from many disparate times and places b ...

'', ''

Ricardoestesia ''Richardoestesia'' is a morphogenus of theropod dinosaur teeth, originally described from the Late Cretaceous of what is now North America. It currently contains two species, ''R. gilmorei'' and ''R. isosceles''. It has been used as a morphot ...

'', ''

Edmontosaurus ''Edmontosaurus'' ( ) (meaning "lizard from Edmonton") is a genus of hadrosaurid (duck-billed) dinosaur. It contains two known species: '' Edmontosaurus regalis'' and '' Edmontosaurus annectens''. Fossils of ''E. regalis'' have been found in ro ...

'', ''

Edmontonia ''Edmontonia'' is a genus of panoplosaurin nodosaurid dinosaur from the Late Cretaceous Period. It is part of the Nodosauridae, a family within Ankylosauria. It is named after the Edmonton Formation (now the Horseshoe Canyon Formation in Canad ...

'', ''

Ankylosaurus ''Ankylosaurus'' is a genus of armored dinosaur. Its fossils have been found in geological formations dating to the very end of the Cretaceous Period, about 68–66 million years ago, in western North America, making it among the last of the ...

'', and ''

Pachycephalosaurus ''Pachycephalosaurus'' (; meaning "thick-headed lizard", from Greek ''pachys-/'' "thick", ''kephale/'' "head" and ''sauros/'' "lizard") is a genus of pachycephalosaurid dinosaurs. The type species, ''P. wyomingensis'', is the only known species ...

''.Wroblewski, 1995 Some of the fluvial channels contain evidence of tidal influence and brackish water, in the form of tidal facies, shark teeth, and shrimp burrows. This demonstrates that the western shoreline of the

Western Interior Sea The Western Interior Seaway (also called the Cretaceous Seaway, the Niobraran Sea, the North American Inland Sea, and the Western Interior Sea) was a large inland sea that split the continent of North America into two landmasses. The ancient sea, ...

was still within a few hundred kilometers even during the latest Cretaceous. The local K-T boundary is contained within a sandy channel deposit made up of stacked bars. Reworked Cretaceous fossils are preserved at the base of the channel complex, associated with mud rip-up clasts, and Paleocene mammal fossils are preserved in the upper portion of the bar.Lillegraven & Eberle, 1999 The Ferris Formation is up to thick in the

Hanna Basin Hannah or Hanna may refer to: People, biblical figures, and fictional characters * Hannah (name), a female given name of Hebrew origin * Hanna (Arabic name), a family and a male given name of Christian Arab origin * Hanna (Irish surname), a fami ...

and represents a rapid accumulation of predominantly fine-grained sediment on a broad delta. The delta previously fed the deepwater

Lewis Shale The Lewis Shale is a geologic formation in the Western United States. It preserves fossils dating back to the Campanian to Maastrichtian stages of the late Cretaceous period. Description The Lewis Shale is an olive-gray marine shale with some ...

and shallow marine

Fox Hills Formation The Fox Hills Formation is a Cretaceous geologic formation in the northwestern Great Plains of North America. It is present from Alberta on the north to Colorado in the south. Fossil remains of dinosaurs, including tyrannosaurs, as well as larg ...

. The Ferris followed behind as a system of lagoons, bays, and delta plain environments.

Vertebrate paleofauna

In addition to a variety of dinosaurs, the following taxa are known from the Ferris Formation: * ''

Myledaphus ''Myledaphus'' is a genus of Late Cretaceous cartilaginous fish whose fossils are known from Canada, the Midwest of the United States, Olmos Formation of the Difunta Group of Mexico, and the Beshtyubin and Bissekty Formations of Uzbekistan. It ...

'' * ''

Lissodus ''Lissodus'' is an extinct genus of freshwater shark. It lived from the Early Carboniferous stage Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early ...

'' * ''

Cretorectolobus ''Cretorectolobus'' is an extinct carpet shark. It was described by G.R. Case in 1978, and the type species is ''C. olsoni'', which existed during the Campanian in Canada and the United States. Another species, ''C. gracilis'', was described by C ...

'' * '' Phylodus'' * ''

Amia Amia, AMIA, or AMiA may refer to: * ''Amia'' (fish), a genus of fish * American Medical Informatics Association *Anglican Mission in the Americas * Asociación Mutual Israelita Argentina, a Jewish community center in Buenos Aires, Argentina ** AM ...

'' * ''

Lepisosteus ''Lepisosteus'' is a genus of gars in the family Lepisosteidae. Distribution While in the present day, ''Lepisosteus'' is only known across North America, fossil remains show it was much more widespread in the past, with specimens known from ...

'' * ''

Basilemys ''Basilemys'' () is a large, terrestrial trionychoid turtle from the Upper Cretaceous. In Greek, the word "Basil" means royal or kingly and the word "Emys" means turtle. Therefore, ''Basilemys'' means King Turtle. ''Basilemys'' has been found in r ...

'' * '' Adocus'' * '' Leptochamops'' * ''

Brachychampsa ''Brachychampsa'' is an extinct genus of alligatoroid, possibly a basal caiman. Specimens have been reported from New Mexico, Colorado, Wyoming, Montana, North and South Dakota, New Jersey, and Saskatchewan, though only those from Montana, Utah, ...

'' and a variety of Cretaceous and Paleocene

multituberculates Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the Middle Jurassic, ...

marsupial Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a ...

, and

placentals Placental mammals (infraclass Placentalia ) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupialia. Placentalia contains the vast majority of extant mammals, which are partly distinguishe ...

Ornithischians

Saurischians

References

Bibliography

* * * {{cite LSA , last=Lillegraven , first=Jason A. , last2=Eberle , first2=Jaelyn J. , year=1999 , title=Vertebrate Faunal Changes through Lancian and Puercan Time in Southern Wyoming , url=https://www.jstor.org/stable/1306768 , journal=

Journal of Paleontology The ''Journal of Paleontology'' is a peer-reviewed scientific journal covering the field of paleontology. It is published by the Paleontological Society. Indexing The ''Journal of Paleontology'' is indexed in: *BIOSIS Previews *Science Citatio ...

, volume=73 , issue=4 , pages=691–710 , accessdate=2020-11-16 Geologic formations of Wyoming Upper Cretaceous Series of North America Paleogene United States Maastrichtian Stage of North America Danian Stage Cretaceous–Paleogene boundary Mudstone formations Sandstone formations of the United States Fluvial deposits Deltaic deposits Tidal deposits Fossiliferous stratigraphic units of North America Paleontology in Wyoming

Vertebrate paleofauna

Ornithischians

Saurischians

See also

References

Bibliography