Ischigualasto Provincial Park ( es, Parque Provincial Ischigualasto), also called ''Valle de la Luna'' ("Valley of the Moon" or "Moon Valley"), due to its moon like appearance, is a provincial protected area in the north-east of San Juan Province, north-western

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

, limiting to the north with the

Talampaya National Park Talampaya National Park ( es, Parque Nacional Talampaya) is a national park located in the east/centre of La Rioja Province, Argentina. It was designated a provincial reserve in 1975, a national park in 1997, and a UNESCO World Heritage Site in 2 ...

, in La Rioja Province. Both areas belong to the same geological formation, the Ischigualasto Formation (sometimes called the Ischigualasto-Talampaya Formation). Established on 3 November 1971, the park has an area of . In 2000,

UNESCO The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations (UN) aimed at promoting world peace and security through international cooperation in education, arts, sciences and culture. It ...

included Ischigualasto and

among its

World Heritage Site A World Heritage Site is a landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites are designated by UNESCO for h ...

History

The name Ischigualasto is derived from the extinct

Cacán language Cacán (also Cacan, Kakán, Calchaquí, Chaka, Diaguita, and Kaka) is an extinct language that was spoken by the Diaguita and Calchaquí tribes in northern Argentina and Chile. It became extinct during the late 17th century or early 18th century. ...

, spoken by an indigenous group referred to as the

Diaguita The Diaguita people are a group of South American indigenous people native to the Chilean Norte Chico and the Argentine Northwest. Western or Chilean Diaguitas lived mainly in the Transverse Valleys which incised in a semi-arid environment. Ea ...

by the

Spanish Spanish might refer to: * Items from or related to Spain: **Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many Latin American countries **Spanish cuisine Other places * Spanish, Ontario, Can ...

conquistadors and means "place where the moon alights".El lugar donde se posa la luna
/ref> Another hypothesis gives the name "Ischigualasto" a

Quechua Quechua may refer to: *Quechua people, several indigenous ethnic groups in South America, especially in Peru *Quechuan languages, a Native South American language family spoken primarily in the Andes, derived from a common ancestral language **So ...

origin, meaning "dead land", although some scholars have proposed

Huarpe The Huarpes or Warpes are an indigenous people of Argentina, living in the Cuyo region. Some scholars assume that in the Huarpe language, this word means "sandy ground," but according to ''Arte y Vocabulario de la lengua general del Reino de Chi ...

roots. The first paleontological description of Ischigualasto dates from 1930. In 1941 the area was studied in more detail, which led to the discovery of 70 species of fossil plants. The region received for the first time the name ''Valle de la Luna'' in 1943, in a publication edited by the Automobil Club Argentino. That year, Dr. Ángel Cabrera of

University of La Plata The La Plata National University ( es, Universidad Nacional de La Plata, UNLP) is one of the most important Argentine national universities and the biggest one situated in the city of La Plata, capital of Buenos Aires Province. It has over 90 ...

described the

traversodontid Traversodontidae is an extinct family of herbivorous cynodonts. Traversodonts were primarily Gondwanan, with many species known from Africa and South America. Recently, traversodonts have also been found from Europe and eastern North America. Tra ...

Exaeretodon ''Exaeretodon'' is an extinct genus of fairly large, low-slung traversodontid cynodonts from the southern parts of Pangea. Four species are known, from various formations. ''E. argentinus'' is from the Carnian-age (Late Triassic) Cancha de Boch ...

''—the first cynodont found in Ischigualasto—after samples sent by a

geologist A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, earth science, or geophysics, althoug ...

prospecting for coal on behalf of an Argentine mining company. Academic work and geological prospecting proceeded slowly until 1958, when Dr. Alfred Sherwood Romer, a

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of high ...

expert in ancient mammals, discovered several rich fossil beds which he described as "extraordinary".

Description

Most of the park lies within the Valle Fértil Department, with a minor part in the Jachal Department of San Juan, at an altitude of about amsl. The park is part of the western border of the

Central Sierras The Sierras Pampeanas (also called Central Sierras or Pampas Sierras) (English: Pampas Mountains) is a geographical region of Argentina. The Sierras Pampeanas are a chain of mountains that rise sharply from the surrounding pampa region of N ...

, and it features typical desert vegetation (bushes, cacti and some trees) which covers between 10 and 20% of the area. The climate is very dry, with rainfall mostly during the summer, and temperature extremes (minimum , maximum ). There is a constant southern wind with a speed of after noon and until the evening, sometimes accompanied by the extremely strong

Zonda wind Zonda wind ( es, viento zonda) is a regional term for the foehn wind that often occurs on the eastern slope of the Andes, in Argentina. Formation The Zonda is a dry wind (often carrying dust) which comes from the polar maritime air, warmed by des ...

. Las Coloradas.JPG, ''Las Coloradas'' cliff P1010357 1.JPG, Water-eroded

badlands Badlands are a type of dry terrain where softer sedimentary rocks and clay-rich soils have been extensively eroded."Badlands" in ''Chambers's Encyclopædia''. London: George Newnes, 1961, Vol. 2, p. 47. They are characterized by steep slopes, m ...

Ischigualasto02.jpg, ''The Sphynx'', wind-eroded rock formation A - Valle de la Luna, el hongo, San Juan, Argentina.jpg, ''The Mushroom'', wind-eroded rock formation

Paleontology

The Ischigualasto Formation contains Late

Triassic The Triassic ( ) is a geologic period and system (stratigraphy), system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Year#Abbreviations yr and ya, Mya), to the beginning of the Jurassic Period 201.36 ...

(

Carnian The Carnian (less commonly, Karnian) is the lowermost stage (stratigraphy), stage of the Upper Triassic series (stratigraphy), Series (or earliest age (geology), age of the Late Triassic Epoch (reference date), Epoch). It lasted from 237 to 227 m ...

) deposits (231.4 -225.9 million years before the present), with some of the oldest known

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

remains, which are the world's foremost with regards to quality, number and importance. In the Carnian this area was a volcanically active

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

dominated by rivers and had a strongly seasonal rainfall.

Petrified tree Petrified wood, also known as petrified tree (from Ancient Greek meaning 'rock' or 'stone'; literally 'wood turned into stone'), is the name given to a special type of '' fossilized wood'', the fossilized remains of terrestrial vegetation. ' ...

trunks of ''Protojuniperoxylon ischigualastianus'' more than tall attest to a rich vegetation at that time. Fossil

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes exce ...

s and

horsetail ''Equisetum'' (; horsetail, snake grass, puzzlegrass) is the only living genus in Equisetaceae, a family of ferns, which reproduce by spores rather than seeds. ''Equisetum'' is a "living fossil", the only living genus of the entire subclass ...

s have also been found.

Rhynchosaur Rhynchosaurs are a group of extinct herbivorous Triassic archosauromorph reptiles, belonging to the order Rhynchosauria. Members of the group are distinguished by their triangular skulls and elongated, beak like premaxillary bones. Rhynchosaurs ...

s and cynodonts (especially

rhynchosaur Rhynchosaurs are a group of extinct herbivorous Triassic archosauromorph reptiles, belonging to the order Rhynchosauria. Members of the group are distinguished by their triangular skulls and elongated, beak like premaxillary bones. Rhynchosaurs ...

Hyperodapedon ''Hyperodapedon'' is a genus of rhynchosaurs (beaked, archosaur-like reptiles) from the Late Triassic period (Carnian stage). Fossils of the genus have been found in Africa, Asia, Europe and North and South America. Its first discovery and namin ...

'' and cynodont ''Exaeretodon'') are by far the predominant findings among the

tetrapod Tetrapods (; ) are four-limbed vertebrate animals constituting the superclass Tetrapoda (). It includes extant and extinct amphibians, sauropsids ( reptiles, including dinosaurs and therefore birds) and synapsids ( pelycosaurs, extinct t ...

fossils in the park. A study from 1993 found

specimens to comprise only 6% of the total tetrapod sample; subsequent discoveries increased this number to approximately 11% of all findings. Carnivorous dinosaurs are the most common terrestrial carnivores of the Ischigualasto Formation, with herrerasaurids comprising 72% of all recovered terrestrial carnivores. Dinosaurs of Ischigualasto Formation include early samples of the two major lineages of dinosaurs (

ornithischian Ornithischia () is an extinct order of mainly herbivorous dinosaurs characterized by a pelvic structure superficially similar to that of birds. The name ''Ornithischia'', or "bird-hipped", reflects this similarity and is derived from the Greek st ...

s and

saurischian Saurischia ( , meaning "reptile-hipped" from the Greek ' () meaning 'lizard' and ' () meaning 'hip joint') is one of the two basic divisions of dinosaurs (the other being Ornithischia), classified by their hip structure. Saurischia and Ornithis ...

s). The carnivorous archosaur '' Herrerasaurus'' is the most numerous of these dinosaur fossils. Another important putative dinosaur with primitive characteristics is ''

Eoraptor lunensis ''Eoraptor'' () is a genus of small, lightly built, basal sauropodomorph. One of the earliest-known dinosaurs, it lived approximately 231 to 228 million years ago, during the Late Triassic in Western Gondwana, in the region that is now northwes ...

'', found in Ischigualasto in the early 1990s.

References

Bibliography

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External links