Mount Blanco
Encyclopedia
Mount Blanco is a small white hill — an erosional remnant — located on the eastern border of the Llano Estacado
within Blanco Canyon
in Crosby County, Texas. It is the type locality of the Blanco Formation and Blancan Fauna
, which occurs throughout North America
.
. The thickness of the Blanco beds varies from around 22 to 26 m (72.2 to 85.3 ft) thick at the most. The formation mainly consists of light-gray fine-grained mudstone
, sandstone
, and some conglomerate
. These light-colored sediments contrast sharply with the rust-colored sediments of the Ogallala Formation
.
Llano Estacado
Llano Estacado , commonly known as the Staked Plains, is a region in the Southwestern United States that encompasses parts of eastern New Mexico and northwestern Texas, including the South Plains and parts of the Texas Panhandle...
within Blanco Canyon
Blanco Canyon
Blanco Canyon is a canyon located in the U.S. state of Texas. Eroded by the White River into the Caprock Escarpment on the east side of the Llano Estacado, the canyon runs for in a southeasterly direction, gradually widening from its beginning in southwestern Floyd County to across at its mouth...
in Crosby County, Texas. It is the type locality of the Blanco Formation and Blancan Fauna
Blancan
The Blancan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology , typically set from 4,750,000 to 1,808,000 years BP, a period of .. It is usually considered to start in the early-mid Pliocene epoch and end...
, which occurs throughout North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
.
Geology
The term "Blanco Canyon beds", later shortened to "Blanco beds", was first applied to this formation in 1890 by William F. Cummins of the Geological Survey of Texas. The Blanco beds are considered to be of lacustrine origin – deposited in a Pleistocene lake basin set in the Ogallala formation of Pliocene age which underlies the upper surface sediments of the Llano EstacadoLlano Estacado
Llano Estacado , commonly known as the Staked Plains, is a region in the Southwestern United States that encompasses parts of eastern New Mexico and northwestern Texas, including the South Plains and parts of the Texas Panhandle...
. The thickness of the Blanco beds varies from around 22 to 26 m (72.2 to 85.3 ft) thick at the most. The formation mainly consists of light-gray fine-grained mudstone
Mudstone
Mudstone is a fine grained sedimentary rock whose original constituents were clays or muds. Grain size is up to 0.0625 mm with individual grains too small to be distinguished without a microscope. With increased pressure over time the platey clay minerals may become aligned, with the...
, sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
, and some conglomerate
Conglomerate (geology)
A conglomerate is a rock consisting of individual clasts within a finer-grained matrix that have become cemented together. Conglomerates are sedimentary rocks consisting of rounded fragments and are thus differentiated from breccias, which consist of angular clasts...
. These light-colored sediments contrast sharply with the rust-colored sediments of the Ogallala Formation
Ogallala Aquifer
The Ogallala Aquifer, also known as the High Plains Aquifer, is a vast yet shallow underground water table aquifer located beneath the Great Plains in the United States...
.
Fossil Fauna
All fossil fauna from Mount Blanco modified from Dalquest (1975) unless otherwise noted.- Class Mammalia
- Order Perissodactyla
- Family EquidaeEquidaeEquidae is the taxonomic family of horses and related animals, including the extant horses, donkeys, and zebras, and many other species known only from fossils. All extant species are in the genus Equus...
- †EquusEquusEquus may refer to:* Equus , a genus of animals including horses, donkeys, zebras and onagers* Equus , a play by Peter Shaffer* Equus , a film adaptation of the Peter Shaffer play...
cumminsi - †Equus simplicidens
- †NannippusNannippusNannippus is an extinct genus of horse endemic to North America during the Miocene through Pliocene, ~13.3—3.3 Ma, living approximately .Nannippus lived as far south as Central Mexico to as far north as Canada , to California in the west, North Carolina and Florida Nannippus is an extinct genus...
peninsulatus
- †Equus
- Family Equidae
- Order Artiodactyla
- Family Antilocapridae
- Family Camelidae
- †BlancocamelusBlancocamelusBlancocamelus is an extinct genus of terrestrial herbivore the family Camelidae, endemic to North America during the Pliocene through Pleistocene 4.9 mya—300,000 years ago, existing for approximately .-Taxonomy:...
meadei - †CamelopsCamelopsCamelops is an extinct genus of camels that once roamed western North America, where it disappeared at the end of the Pleistocene about 10,000 years ago. Its name is derived from the Greek κάμελος + , thus "camel-face."-Background:...
traviswhitei - †Canimartes cumminsi
- †Blancocamelus
- Family Cervidae
- †OdocoileusOdocoileusOdocoileus is a genus of medium-sized deer containing two species native to the Americas. The name is sometimes spelt odocoeleus; it is from a contraction of the roots odonto- and coelus meaning "hollow-tooth".-Species:...
brachyodontus
- †Odocoileus
- Family Tayassuidae
- †PlatygonusPlatygonusPlatygonus is an extinct genus of herbivorous peccary of the family Tayassuidae, endemic to North America from the Miocene through Pleistocene epochs , existing for approximately ....
biccalcaratus - †TitanotylopusTitanotylopusTitanotylopus is an extinct genus of terrestrial herbivore the family Camelidae, endemic to North America from the Miocene through Pleistocene 10.3 mya—300,000 years ago, existing for approximately ....
spatulus - †Tanupolama blancoensis
- †Platygonus
- Superorder Edentata
- Family †GlyptodontidaeGlyptodontidaeGlyptodonts were large, more heavily armored relatives of extinct pampatheres and modern armadillos.They first evolved during the Miocene in South America, which remained their center of species diversity...
- †Glyptotherium texanum
- Family MegalonychidaeMegalonychidaeMegalonychidae is a group of sloths including the extinct Megalonyx and the living two toed sloths. Megalonychids first appeared in the early Oligocene, about 35 million years ago, in southern Argentina , and spread as far as the Antilles by the early Miocene...
- †MegalonyxMegalonyxMegalonyx is an extinct genus of giant ground sloths of the family Megalonychidae endemic to North America from the Hemphillian of the Late Miocene through to the Rancholabrean of the Pleistocene, living from ~10.3 Mya—11,000 years ago, existing for approximately .-Taxonomy:The generic name...
leptostomus
- †Megalonyx
- Family †MylodontidaeMylodontidaeMylodontidae is a family of extinct mammals within the order of Pilosa and suborder Folivora living from approximately 23 mya—11,000 years ago, existing for approximately . This family of ground sloths is related to the other families of extinct ground sloths, being the Megatheriidae, the...
- †GlossotheriumGlossotheriumGlossotherium was a genus of ground sloth. It was a heavily built animal with a length of about snout to tail-tip, and could potentially assume a slight bipedal stance.Fossils of this animal have been found in South America...
chapadmalens
- †Glossotherium
- Family †Glyptodontidae
- Order LagomorphaLagomorphaThe lagomorphs are the members of the taxonomic order Lagomorpha, of which there are two living families, the Leporidae , and the Ochotonidae...
- Family LeporidaeLeporidaeLeporids are the approximately 50 species of rabbits and hares which form the family Leporidae. The leporids, together with the pikas, constitute the mammalian order Lagomorpha. Leporids differ from pikas in having short furry tails, and elongated ears and hind legs...
- †HypolagusHypolagusHypolagus is an extinct genus of Lagomorpha, first recorded in the Hemingfordian of North America. It enters Asia during the early Turolian and spreads to Europe not much later, where it survives until the Middle Pleistocene...
sp. - †Nekrolagus progressus
- †Hypolagus
- Family Leporidae
- Order ProboscideaProboscideaProboscidea is a taxonomic order containing one living family, Elephantidae, and several extinct families. This order was first described by J. Illiger in 1881 and encompasses the trunked mammals...
- Family †Gomphotheriidae
- †StegomastodonStegomastodonStegomastodon is an extinct genus of gomphothere, a family of proboscideans. It is not to be confused with the genus Mammut from a different proboscidean family, whose members are commonly called "mastodons", nor with the genus Stegodon, from yet another proboscidean sub-family, whose members are...
mirificus
- †Stegomastodon
- Family †Gomphotheriidae
- Order CarnivoraCarnivoraThe diverse order Carnivora |Latin]] carō "flesh", + vorāre "to devour") includes over 260 species of placental mammals. Its members are formally referred to as carnivorans, while the word "carnivore" can refer to any meat-eating animal...
- Family CanidaeCanidaeCanidae is the biological family of carnivorous and omnivorous mammals that includes wolves, foxes, jackals, coyotes, and domestic dogs. A member of this family is called a canid . The Canidae family is divided into two tribes: Canini and Vulpini...
- †BorophagusBorophagusBorophagus is an extinct genus of the subfamily Borophaginae, a group of canids endemic to North America from the early Miocene epoch through the Zanclean stage of the Pliocene epoch 23.3—3.6 Mya. Borophagus existed for approximately .-Overview:Borophagus, like other borophagines, are loosely...
diversidens - †Canis lepophagusCanis lepophagusCanis lepophagus or Hare-eating Wolf is an extinct species of canidae which was endemic to much of North America and lived from the Miocene epoch through Early Pleistocene, 10.3—1.8 Mya. The species existed for approximately . It is one of the more basal species of Canis, having existed before most...
- †Borophagus
- Family FelidaeFelidaeFelidae is the biological family of the cats; a member of this family is called a felid. Felids are the strictest carnivores of the thirteen terrestrial families in the order Carnivora, although the three families of marine mammals comprising the superfamily pinnipedia are as carnivorous as the...
- †FelisFelisFelis is a genus of cats in the family Felidae, including the familiar domestic cat and its closest wild relatives. The wild species are distributed widely across Europe, southern and central Asia, and Africa; the domestic cat has been introduced worldwide.Members of the genus Felis are all small...
cf. lacustris - †DinofelisDinofelisDinofelis is a genus of sabre-toothed cats belonging to the tribe Metailurini. They were widespread in Europe, Asia, Africa and North America at least 5 million to about 1.2 million years ago...
palaeoonca - †HomotheriumHomotheriumHomotherium is an extinct genus of machairodontine saber-toothed cats, often termed scimitar cats, endemic to North America, South America, Europe, Asia, and Africa during the Pliocene and Pleistocene epochs , existing for approximately .It first became extinct in Africa some 1.5 million years ago...
- †Felis
- Family Hyaenidae
- †ChasmaporthetesChasmaporthetesChasmaporthetes, also known as Hunting or Running Hyena, is an extinct genus of hyena endemic to North America, Africa, and Asia during the Pliocene-Pleistocene epochs, living from 4.9 mya—780,000 years ago, existing for approximately . The genus probably arose from Eurasian Miocene hyenas such as...
ossifragus
- †Chasmaporthetes
- Family MustelidaeMustelidaeMustelidae , commonly referred to as the weasel family, are a family of carnivorous mammals. Mustelids are diverse and the largest family in the order Carnivora, at least partly because in the past it has been a catch-all category for many early or poorly differentiated taxa...
- †Canimartes cummins
- †Spilogale rexroadi
- Family Canidae
- Order Rodentia
- Family Sciuridae
- †Paenemarmota barbouri
- SpermophilusSpermophilusSpermophilus is a genus of ground squirrels in the family Sciuridae. The majority of ground squirrel species, over 40 in total, are usually placed in this genus...
sp. - †Spermophilius howelli
- Family Geomyidae
- Geomys sp.
- Family HeteromyidaeHeteromyidaeThe family of rodents that include kangaroo rats, kangaroo mice and rock pocket mice is the Heteromyidae family. Most heteromyids live in complex burrows within the deserts and grasslands of western North America, though species within the Heteromys and Liomys genera are also found in forests and...
- †PerognathusPerognathusPerognathus is a genus of pocket mouse. Like other members of their family they are more closely related to pocket gophers than to true mice.-Characteristics:...
parlettensis - †Perognathus rexroadensis
- †Prodipomys centralis
- †Perognathus
- Family CricetidaeCricetidaeThe Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, and New World rats and mice...
- BaiomysBaiomysBaiomys is the genus of New World pygmy mice. Together with Scotinomys, it forms the tribe Baiomyini. It currently contains two extant species:*Southern Pygmy Mouse, Baiomys musculus*Northern Pygmy Mouse, Baiomys taylori-References:...
sp. - †Bensonomys?Oryzomys pliocaenicus?Oryzomys pliocaenicus is a fossil rodent from the Hemphillian of Kansas, central United States. It is known from a single mandible with the back part missing. All three molars are present, but very worn. Together, the molars are 3.6 mm long...
sp. - †Neotoma quadriplicatus
- Onychomys sp.
- † PeromyscusPeromyscusThe genus Peromyscus contains the animal species commonly referred to as deer mice. This is a genus of New World mouse only distantly related to the common house mouse and laboratory mouse, Mus musculus...
kansasensis - ReithrodontomysReithrodontomysReithrodontomys is the genus of groove-toothed New World harvest mice.-Species:This genus contains twenty species:*Guerrero Harvest Mouse *Short-Nosed Harvest Mouse...
sp. - †Sigmodon medius
- Baiomys
- Family Sciuridae
- Order Perissodactyla
- Class Reptilia
- Order Testudinata
- Family Testudinidae
- GeocheloneGeocheloneGeochelone is a genus of tortoises.Geochelone tortoises, which are also known as typical tortoises or terrestrial turtles, can be found in Africa and Asia. They primarily eat plants.The genus consists of three extant species:...
sp.
- Geochelone
- Family Testudinidae
- Order Testudinata
See also
- Blanco CanyonBlanco CanyonBlanco Canyon is a canyon located in the U.S. state of Texas. Eroded by the White River into the Caprock Escarpment on the east side of the Llano Estacado, the canyon runs for in a southeasterly direction, gradually widening from its beginning in southwestern Floyd County to across at its mouth...
- White River (Texas)White River (Texas)The White River is an intermittent stream in the South Plains of Texas and a tributary of the Brazos River of the United States. It rises west of Floydada in southwestern Floyd County at the confluence of Callahan and Runningwater Draws. From there, it runs southeast for to its mouth on the...
- BlancanBlancanThe Blancan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology , typically set from 4,750,000 to 1,808,000 years BP, a period of .. It is usually considered to start in the early-mid Pliocene epoch and end...
- Caprock EscarpmentCaprock EscarpmentThe Caprock Escarpment is a term used in Texas and Eastern New Mexico to describe the geographical transition point between the level elevated plains of the Llano Estacado and the surrounding rolling terrain. In Texas, the escarpment stretches around 320 km south-southwest from the northeast...
- Yellow House CanyonYellow House CanyonYellow House Canyon is a canyon that is about long, heading in Lubbock, Texas, at the junction of Blackwater Draw and Yellow House Draw, and trending generally southeastward to the edge of the Llano Estacado about east of Slaton, Texas; it forms one of three major canyons along the east side of...
- Double Mountain Fork Brazos RiverDouble Mountain Fork Brazos RiverThe Double Mountain Fork Brazos River is an ephemeral, sandy-braided stream about long, heading on the Llano Estacado of West Texas about southeast of Tahoka, Texas, flowing east-northeast across the western Rolling Plains to join the Salt Fork, forming the Brazos River about west-northwest of...
- Palo Duro CanyonPalo Duro CanyonPalo Duro Canyon is a canyon system of the Caprock Escarpment located in the Texas Panhandle near the city of Amarillo, Texas, United States. As the second largest canyon in the United States, it is roughly long and has an average width of , but reaches a width of at places. Its depth is around...