Ischigualasto Provincial Park

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Ischigualasto Provincial Park
Parque Provincial Ischigualasto
Valle de la Luna
The Submarine, wind-eroded rock formation
The Submarine, wind-eroded rock formation
Location in Argentina
Location in Argentina
Location in Argentina
Location San Juan Province, Argentina
Nearest city San José de Jáchal
Coordinates 30°4′0″S 68°0′0″W / 30.06667°S 68.00000°W / -30.06667; -68.00000Coordinates: 30°4′0″S 68°0′0″W / 30.06667°S 68.00000°W / -30.06667; -68.00000
Area 60,370 ha (603.7 km2; 233.1 sq mi)
Established November 3, 1971 (1971-11-03)[1]
Official name
Ischigualasto / Talampaya Natural Parks
Type Natural
Criteria viii
Designated 2000 (24th session)
Reference no. 966[2]
State Party  Argentina
Region Latin America and the Caribbean

Ischigualasto Provincial Park (Spanish: Parque Provincial Ischigualasto), also called Valle de la Luna ("Valley of the Moon" or "Moon Valley"), due to its otherworldly appearance, is a provincial protected area in the north-east of San Juan Province, north-western Argentina, limiting to the north with the Talampaya National Park, in La Rioja Province. Both areas belong to the same geological formation, the Ischigualasto Formation (sometimes Ischigualasto-Talampaya Formation) Established on 3 November 1971,[1] the park has an area of 60,370 ha (603.7 km2; 233.1 sq mi)

In 2000 UNESCO included Ischigualasto and Talampaya National Park among its World Heritage Sites.[2]


The most accepted hypothesis gives the name "Ischigualasto" a Quechua origin, meaning "place where the moon sets", although some scholars have proposed Diaguita or Huarpe 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 described the traversodontid Exaeretodon—the first cynodont found in Ischigualasto—after samples sent by a geologist who was doing prospecting for coal on behalf of an Argentine mining company.[3]

Academic work and geological prospecting proceeded slowly until 1958, when Dr. Alfred Sherwood Romer, a Harvard University expert in ancient mammals, discovered several rich fossil beds which he described as "extraordinary".


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 1,300 m (4,300 ft) amsl. The park is part of the western border of the Central Sierras, 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 −10 °C (14 °F), maximum 45 °C (113 °F)). There is a constant southern wind with a speed of 20–40 km/h (12–25 mph) after noon and until the evening, sometimes accompanied by the extremely strong Zonda wind.


See also: Choiyoi Group

The Ischigualasto Formation contains Late Triassic (Carnian) deposits (231.4 -225.9 million years before the present[4]), with some of the oldest known dinosaur remains, which are the world's first with regards to quality, number and importance. It is the only place in the world where nearly all of the Triassic is represented in an undisturbed sequence of rock deposits. This allows for the study of the transition between dinosaurs and ancient mammals; research is ongoing.

In the Carnian this area was a volcanically active floodplain dominated by rivers and had a strongly seasonal rainfall. Petrified tree trunks of Protojuniperoxylon ischigualastianus more than 40 m (130 ft) tall attest to a rich vegetation at that time. Fossil ferns and horsetails have also been found.

Rhynchosaurs and cynodonts (especially rhynchosaur Hyperodapedon and cynodont Exaeretodon[4]) are by far the predominant findings among the tetrapod fossils in the park. A study from 1993 found dinosaur specimens to comprise only 6% of the total tetrapod sample;[5] subsequent discoveries increased this number to approximately 11% of all findings.[4] Carnivorous dinosaurs are the most common terrestrial carnivores of the Ischigualasto Formation, with herrerasaurids comprising 72% of all recovered terrestrial carnivores.[4] Dinosaurs of Ischigualasto Formation include early samples of the two major lineages of dinosaurs (ornithischians and saurischians). The carnivorous archosaur Herrerasaurus is the most numerous of these dinosaur fossils. Another important putative dinosaur with primitive characteristics is Eoraptor lunensis, found in Ischigualasto in the early 1990s.


The fossils of an undescribed species of theropod are present in San Juan Province.[6]

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Dinosaurs of the Ischigualasto Formation
Genus Species Location Stratigraphic position Material Notes Images


C. novasi

San Juan Province[7]

Cancha de Bochas Member[7]

Partial skeleton including limb bones, pelvic bones and caudal vertebrae[7]

Basal sauropodomorph closely related to Saturnalia[7]


E. murphi

San Juan Province[4]

Valle de la Luna Member

A nearly complete skeleton and another partial skeleton

Basal theropod


E. lunensis[6]

San Juan Province[6]

Two nearly complete skeletons[8]

Basal saurischian, possibly a theropod[7] or sauropodomorph[4]


F. ischigualastensis[6]

San Juan Province[6]

Jr. synonym of Herrerasaurus ischigualastensis


H. ischigualastensis[6]

San Juan Province[6]

"Various partial skeletons, including a complete skull and mandible."[8]

A herrerasaurid, basal saurischian[7] or theropod[4] Includes Ischisaurus cattoi, Frenguellisaurus ischigualastensis, and cf. Staurikosaurus sp.[6]


I. cattoi[6]

San Juan Province[6]

Jr. synonym of Herrerasaurus ischigualastensis


P. protos[9]

San Juan Province[6]

One of the basalmost known genera of sauropodomorphs[7][9][10]


P. mertii[6]

La Rioja Province[6]

"Fragmentary skull and skeleton."[11]

One of the earliest known ornithischians


S. gordilloi

San Juan Province[12]

Cancha de Bochas Member[12]

An incomplete skeleton[12]

A herrerasaurid

cf. Staurikosaurus


San Juan Province[6]

Remains previously referred to "cf. Staurikosaurus" were later determined to belong to Herrerasaurus[6]

An unnamed herrerasaurian[7]


Specimen MACN-PV 18649a[7]

A herrerasaurian distinct from Herrerasaurus, Staurikosaurus and Sanjuansaurus.[7]

Other archosauromorphs[edit]

Non-dinosaurian archosauromorphs of the Ischigualasto Formation[7][13]
Genus Species Location Stratigraphic position Material Notes Images


A. scagliai

An aetosaur


I. fragilis[13]

San Juan Province[13]

Right ilium[13]

A silesaurid.[13]


P. barrionuevoi

A proterochampsian


P. ischigualastensis[14]

San Juan Province[15]

Cancha de Bochas Member[15]

An articulated incomplete skeleton[15]

A proterochampsian. Originally described a species of Chanaresuchus,[15] subsequently made the type species of a separate genus Pseudochampsa.[14]


S. galilei

A rauisuchian


S. sanjuanensis[13]

A rhynchosaur. The species is assigned by some authors to the genus Hyperodapedon instead.[7]


S. longicervix

A shuvosaurid


T. romeri

A putative basal crocodylomorph


V. rusconii[13]

An ornithosuchid

An unnamed lagerpetid[16][13]


San Juan Province[16][13]

Distal end of the left femur[13]

A basal dinosauromorph.


Synapsids of the Ischigualasto Formation[7][13]
Genus Species Location Stratigraphic position Material Notes Images


C. sanjuanensis, C. cf. theotonicus[13]

A cynodont


D. elegans

San Juan Province

Cancha de Bochas Member

Partial skull, represented by the snout and the orbital region, with partially preserved upper dentition

A cynodont


E. lunensis

A cynodont


E. frenguellii

A cynodont



A dicynodont


J. colorata[13]

A dicynodont

cf. Probainognathus


A cynodont

An unnamed eucynodont[13]


Specimen PVSJ 882 (a cranium)[13]

Other tetrapods[edit]

Other tetrapods of the Ischigualasto Formation[7][13]
Genus Species Location Stratigraphic position Material Notes Images


P. ischigualastensis

A temnospondyl


P. bellmanni

A temnospondyl

See also[edit]


  1. ^ a b Ley No. 3666 de la Provincia de San Juan, 11 de noviembre de 1971; sanc.: 3 de noviembre de 1971
  2. ^ a b "Ischigualasto / Talampaya Natural Parks". UNESCO World Heritage Centre. 
  3. ^ Cabrera 1943.
  4. ^ a b c d e f g Martínez et al. 2011.
  5. ^ Rogers et al. 1993.
  6. ^ a b c d e f g h i j k l m n o p q r s t Weishampel et al. 2004, pp. 527–528.
  7. ^ a b c d e f g h i j k l m n Ezcurra 2010.
  8. ^ a b Weishampel et al. 2004, p. 26, Table 2.1.
  9. ^ a b c Martínez et al. 2009.
  10. ^ Cabreira et al. 2011.
  11. ^ Weishampel et al. 2004, p. 326, Table 14.1.
  12. ^ a b c d Alcober et al. 2010.
  13. ^ a b c d e f g h i j k l m n o p q r s t u Martínez et al. 2013b.
  14. ^ a b c Trotteyn & Ezcurra 2014.
  15. ^ a b c d Trotteyn et al. 2012.
  16. ^ a b Langer et al. 2013.
  17. ^ Martínez et al. 2013.




  • Langer, Max C.; Nesbitt, Sterling J.; Bittencourt, Jonathas S.; Irmis, Randall B. (2013). "Non-dinosaurian Dinosauromorpha". In Nesbitt, S. J.; Desojo, J. B.; Irmis, R. B. Anatomy, phylogeny and palaeobiology of early archosaurs and their kin. The Geological Society of London. pp. 157–186. doi:10.1144/SP379.9. 
  • Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (2004). The Dinosauria (2 ed.). University of California Press. ISBN 0-520-24209-2. 

External links[edit]