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 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", due to its otherworldly appearance), is a provincial protected area located 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), and have been declared as a World Heritage Site by UNESCO.

History

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".

In 1971 the area was declared a Provincial Park, and in 2000 UNESCO included Ischigualasto and Talampaya National Park among its World Heritage sites.

Description

The park has an area of 603.7 km2 (233.1 sq mi), most of them 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.

Ischigualasto Provincial Park scenery

Cerro Morado

Water-eroded badlands

The Sphynx, wind-eroded rock formation

The Mushroom, wind-eroded rock formation

Paleontology

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.

Dinosaurs

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
 Notes
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

Chromogisaurus

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]
Eodromaeus
Eoraptor
Herrerasaurus
Panphagia
Pisanosaurus
Sanjuansaurus

Eodromaeus

E. murphi

San Juan Province[4]

Valle de la Luna Member

A nearly complete skeleton and another partial skeleton

Basal theropod

Eoraptor[6]

E. lunensis[6]

San Juan Province[6]

Two nearly complete skeletons[8]

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

Frenguellisaurus[6]

F. ischigualastensis[6]

San Juan Province[6]

Jr. synonym of Herrerasaurus ischigualastensis

Herrerasaurus[6]

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]

Ischisaurus[6]

I. cattoi[6]

San Juan Province[6]

Jr. synonym of Herrerasaurus ischigualastensis

Panphagia[9]

P. protos[9]

San Juan Province[6]

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

Pisanosaurus[6]

P. mertii[6]

La Rioja Province[6]

"Fragmentary skull and skeleton."[11]

One of the earliest known ornithischians

Sanjuansaurus[12]

S. gordilloi

San Juan Province[12]

Cancha de Bochas Member[12]

An incomplete skeleton[12]

A herrerasaurid

cf. Staurikosaurus

Indeterminate

San Juan Province[6]

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

An unnamed herrerasaurian[7]

Unnamed

Specimen MACN-PV 18649a[7]

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

Other archosauromorphs

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

Aetosauroides

A. scagliai

An aetosaur

Chanaresuchus[14]

C. ischigualastensis[14]

San Juan Province[14]

Cancha de Bochas Member[14]

An articulated incomplete skeleton[14]

A proterochampsian

Ignotosaurus[13]

I. fragilis[13]

San Juan Province[13]

Right ilium[13]

A silesaurid.[13]

Proterochampsa

P. barrionuevoi

A proterochampsian

Saurosuchus

S. galilei

A rauisuchian

Scaphonyx[13]

S. sanjuanensis[13]

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

Sillosuchus

S. longicervix

A shuvosaurid

Trialestes

T. romeri

A putative basal crocodylomorph

Venaticosuchus[13]

V. rusconii[13]

An ornithosuchid

An unnamed lagerpetid[15][13]

Unnamed

San Juan Province[15][13]

Distal end of the left femur[13]

Synapsids

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

Chiniquodon

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

A cynodont

Diegocanis[16]

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

Ecteninion

E. lunensis

A cynodont

Exaeretodon

E. frenguellii

A cynodont

Ischignathus

I. sudamericanus

A cynodont

Ischigualastia

I. jenseni

A dicynodont

Jachaleria[13]

J. colorata[13]

A dicynodont

cf. Probainognathus

Indeterminate

A cynodont

An unnamed eucynodont[13]

Unnamed[13]

Specimen PVSJ 882 (a cranium)[13]

Other tetrapods

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

Pelorocephalus

P. ischigualastensis

A temnospondyl

Promastodonsaurus

P. bellmanni

A temnospondyl

See also

References

  1. ↑ Provincial Law No. 3666, 3 November 1971
  2. ↑ "Ischigualasto / Talampaya Natural Parks". UNESCO World Heritage Centre. 
  3. ↑ Cabrera 1943.
  4. ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 Martínez et al. 2011.
  5. ↑ Rogers et al. 1993.
  6. ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 6.10 6.11 6.12 6.13 6.14 6.15 6.16 6.17 6.18 6.19 Weishampel et al. 2004, pp. 527–528.
  7. ↑ 7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 7.10 7.11 7.12 7.13 Ezcurra 2010.
  8. ↑ 8.0 8.1 Weishampel et al. 2004, p. 26, Table 2.1.
  9. ↑ 9.0 9.1 9.2 Martínez et al. 2009.
  10. ↑ Cabreira et al. 2011.
  11. ↑ Weishampel et al. 2004, p. 326, Table 14.1.
  12. ↑ 12.0 12.1 12.2 12.3 Alcober et al. 2010.
  13. ↑ 13.0 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 13.10 13.11 13.12 13.13 13.14 13.15 13.16 13.17 13.18 13.19 13.20 Martínez et al. 2013b.
  14. ↑ 14.0 14.1 14.2 14.3 14.4 Trotteyn et al. 2012.
  15. ↑ 15.0 15.1 Langer et al. 2013.
  16. ↑ Martínez et al. 2013.

Bibliography

Articles

Books

  • 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. 

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