Ituzaingó Formation Explained

Ituzaingó Formation
Type:	Geological formation
Period:	Tortonian
Age:	Tortonian (Huayquerian) ~
Prilithology:	Sandstone, mudstone
Otherlithology:	Conglomerate
Namedfor:	Ituzaingó
Namedby:	De Alba
Year Ts:	1953
Location:	Mesopotamia
Region:	Corrientes, Santa Fe & Entre Ríos Provinces
Country:	Argentina
Coordinates:	-31.7°N -60.4°W
Paleocoordinates:	-31.8°N -58.3°W
Subunits:	Conglomerado Osifero Member
Underlies:	Puerto Alvear, Hernandarías, Timbúes & Yupoí Formations
Overlies:	Paraná & Rosario Formations
Thickness:	Up to 150m (490feet) Typically 10-
Extent:	Paraná Basin
Area:	120000km2

The Ituzaingó Formation (Spanish; Castilian: Formación Ituzaingó), in older literature also described as Entre Ríos or Entrerriana Formation, is an extensive geological formation of Late Miocene (Tortonian, or Huayquerian in the SALMA classification) age in the Paraná Basin of the Corrientes, Santa Fe and Entre Ríos Provinces in Mesopotamia, northeastern Argentina.^[1] The formation comprises mudstones, cross-bedded sandstones and conglomerates deposited in a fluvio-deltaic environment and is renowned for the preservation of a rich fossil assemblage, including many mammals, birds, reptiles, fish, bivalves, foraminifera, ichnofossils and flora.

Description

The Ituzaingó Formation was first described by De Alba in 1953 and later by Herbst in 1971.^[2] The up to 150m (490feet), but in most areas between 10mand20mm (30feetand70feetm) thick formation is found in an area of 120000km2,^[3] stretching from the Paraná River to 40km (30miles) east of Tostado.^[4] The Ituzaingó Formation crops out in the northeasternmost part of Argentina (Mesopotamia), in the provinces of Corrientes, Santa Fe and Entre Ríos, among other locations along the banks of the Paraná River.^[5]

Stratigraphy

The formation overlies the marine Paraná Formation and is unconformably overlain by the Puerto Alvear,^[6] Hernandarías and Yupoí Formations of Early Pleistocene (Uquian and Ensenadan respectively) age.^{[5] [7] [8]} At the shores of the Paraná River, the formation underlies the Timbúes Formation.^[9] In certain places along the same river, the formation cuts into the underlying Rosario Formation.^[10]

The formation contains a basal conglomeratic member "Conglomerado osífero" (bony conglomerate) with abundant vertebrate remains.^[11] This conglomerate is overlain by almost unfossiliferous whitish to yellow brown sandstones and green mudstones. The Ituzaingó Formation (as Entre Ríos Formation) was correlated with the Puelches Formation of the subsurface of Buenos Aires Province. According to the mammals occurring in the conglomerate and the stratigraphic relationships, the age of the base of Ituzaingo Formation is almost exclusively Tortonian (Late Miocene) or Huayquerian in the SALMA classification.^[12]

Depositional environment

The formation, as the Paraná and Puelches Formations, has been deposited in a vast Miocene tidal flat environment.^[13] Both the terrestrial and freshwater fauna of the Ituzaingó Formation indicates a climate warmer than present. The freshwater vertebrate record suggests important basin connections with Amazonian basins.^[11]

Alternatively, the Conglomerado Osífero Member has been interpreted as tide-dominated fluvial channels, pertaining to the marine Paraná Formation.^[14]

Fossil content

The Ituzaingó Formation has provided a large variety of fossils, of various groups, from mammals to birds and reptiles to fish and flora. The terrestrial fauna is predominant while a few marine genera are also present.^[15] The presence of typical Amazonian freshwater fish and absence of austral fauna in both the underlying Paraná and the Ituzaingó Formation suggests a connection with northern areas of South America. The faunas has been correlated to the older Miocene faunas of the Honda Group at La Venta in Colombia, the Urumaco Formation at Urumaco in Venezuela and the Pebas Formation of the Amazon region of Colombia, Ecuador, Peru and Brazil.^[16] Several ground sloth genera present in the Ituzaingó Formation are endemic from this unit, whereas other are also present in the Arroyo Chasicó Formation of Buenos Aires Province, the Andalhuala and Corral Quemado Formations of Catamarca Province, and the Toro Negro Formation of La Rioja Province.^[17]

Birds

Taxa	Species	Presence	Abundance	Description	Images	Notes
Andalgalornis	A. steulleti
Devincenzia	D. pozzi
Macranhinga	M. paranensis
	M. ranzii
Palaelodus	P. cf. ambiguus
Rhea	R. (Pterocnemia) mesopotamica
Megapaloelodus	M. sp.
Phoenicopteridae	Indeterminate.
Phorusrhacidae	Indetermidate.
Rallidae	Indeterminate.
	Indeterminate.

Mammals

Chiroptera

Taxa	Species	Presence	Abundance	Description	Images	Notes
Eumysops	E. parodii
Notictis	N. ortizi

Litopterns

Taxa	Species	Presence	Abundance	Description	Images	Notes
Brachytherium	B. cuspidatum
Cullinia	C. sp.
Diadiaphorus	D. paranensis
Neobrachytherium	N. ameghinoi
Rowspan =2	Oxyodontherium	O. piramydatus			Rowspan = 2
O. zeballosi
Paranauchenia	P. denticulata
Promacrauchenia	P. antiqua
Proterotherium	P. cervioides
Scalabrinitherium	S. bravardi
	S. rothii

Marsupials

Taxa	Species	Presence	Abundance	Description	Images	Notes
Philander	P. entrerianus
Chironectes	C. sp.
Zygolestes	Z. paranensis

Sparassodonts

Taxa	Species	Presence	Abundance	Description	Images	Notes
Thylacosmilus	T. atrox
Stylocynus	S. paranensis

Rodents

Taxa	Species	Presence	Abundance	Description	Images	Notes
Briaromys	B. trouessartianus
Cardiatherium	C. paranense
Carlesia	C. pendolai
Diaphoromys	D. compressidens
	D. gamayensis
	D. mesopotamicus
Doellomys	D. parcus
Eumegamys	E. contortus
	E. dubius
	E. scalabrinianus
	E. paranensis
Eumegamysops	E. praependens
Gyriabrus	G. glutinatus
	G. holmbergi
	G. indivisus
	G. rebagliattii
Haplostropha	H. sacabriniana
Isostylomys	I. ameghinoi
	I. laurillardi
Lagostomopsis	L. antiquus
	L. pallidens
Myocastor	M. obesus
	M. paranensis
	M. sinuata
Neoepiblema	N. ambrosettianus
	N. horridula
Olenopsis	O. typicus
Paradoxomys	P. cancrivorus
Pentastylodon	P. racedi
Pentastylomys	P. seriei
Perimys	P. scalabrinianus
Phoberomys	P. burmeisteri
	P. insolita
	P. lozanoi
	P. minima
	P. praecursor
Phugatherium	P. cataclisticum
Potamarchus	P. murinus
	P. sigmodon
Protabrocoma	P. paranensis
Protomegamys	P. coligatus
Pseudosigmomys	P. paranensis
Rusconia	R. crassidens
Strophostephanos	S. jheringi
Telodontomys	T. compressidens
Tetrastylomys	T. castellanosi
Tetrastylus	T. aguilari
	T. diffusus
	T. laevigatus
	T. robustus
	T. (Protelicomys) atavus
Anatochoerus
Anchimysops	A. sp.
Cardiatherium
Cardiomys
Caviodon
Colpostemma sp.
Contracavia
Kiyutherium
Paleocavia
Parodimys
Plexochoerus
Pliodolichotis
Procardiatherium
Prodolichotis
Protohydrochoerus

Toxodonts

Taxa	Species	Presence	Abundance	Description	Images	Notes
Adinotherium	?A. paranense
?Berroia	?B. sp.
Dilobodon	D. lutarius
Dinotoxodon	D. paranensis
Eutomodus	E. elautus
Haplodontherium	H. limun
Palaeotoxodon	P. paranensis
	?P. protoburmeisteri
	?P. virgatus
Stenotephanos	S. plicidens
Toxodontherium	T.compressum
	T. reverendum
Xotodon	X. doellojuradi
	X. foricurvatus

Typotheres

Taxa	Species	Presence	Abundance	Description	Images	Notes
Munyizia	M. paranensis
Protypotherium	P. antiquum
Trachytypotherium	T. sp.

Xenarthrans

Cingulates

Taxa	Species	Presence	Abundance	Description	Images	Notes
Berthawyleria	B. sp.
Chasicotatus	C. spinozai
Chlamyphractus	C. pressulus
Comaphorus	C. concisus			A dubious glyptodont.
Dasypus	D. neogarus			Relatives of nine-banded armadillos.
Eleutherocercus	E. paranensis			A glyptodont.
Kraglievichia	K. paranense
Macroeuphractus	M. retusus
Palaehoplophorus	P. antiquus
Paraglyptodon	P. paranensis
Parahoplophorus	P. paranensis
Plohophorus	P. paranensis
Proeuphractus	P. limpidus
Protoglyptodon	P. primiformis
Pseudoeuryurus	P. lelongianus
Scirrotherium	S. carinatum
Trachycalyptus	?T. cingulatus
Urotherium	U. interundatum
Zaedyus	?Z. sp.

Ground sloths

Taxa	Species	Presence	Abundance	Description	Images	Notes
Amphiocnus	A. paranense
Eomegatherium	E. nanum
Megabradys	M. darwini
Megalonychops	M. primigenius
Mesopotamocnus	M. brevirostrum
Neohapalops	N. rothi
Octomylodon	O. aversus
Ortotherium	O. laticurvatum
	O. robustum
	O. schlosseri
	O. scrofum
	O. seneum
Paranabradys	P. vucetichae
Pliomegatherium	P. lelongi
Pliomorphus	P. ameghinoi
	P. gracilis
	P. mutilatus
	P. robustus
Prolestodon	P. antiquus
	P. paranensis
Promegatherium	P. parvulum
	P. smaltatum
Promylodon	P. paranensis
Pronothrotherium	P. mirabilis
Protomegalonyx	P. doellojuradoi
	P. praecursor
Pyramiodontherium	P. sp.
Ranculcus	R. scalabrinianus
Scelidotheriidae	Indeterminate.
Sphenotherus	S. paranensis
Strabosodon	S. acuticavus
	S. obtusicavus
Torcellia	T. paranense

Other Mammals

Reptiles

Taxa	Species	Presence	Abundance	Description	Images	Notes
Caiman	C. australis
	C. cf. yacare
	C. gasparinae
	C. latriostris
	C. lutescens
	C. yacare
Gryposuchus	G. neogaeus
Mourasuchus	M. arendsi
Tupinambis	T. cf. merianae
Parahydraspis	P. paranaensis
Phrynops	P. cf. geoffroanus
Testudo	T. paranensis

Fish

Taxa	Species	Presence	Abundance	Description	Images	Notes
Colossoma	C. macropomum
Megapiranha	M. paranensis
Potamotrygon	P. motoro
Squatina	S. dumeril
Phractocephalus	P. ivy
Cynodontidae	Indetermidate.

Invertebrates

Taxa	Species	Presence	Abundance	Description	Images	Notes
Protelphidium	P. tuberculatum
Ostrea	O. sp.

Microflora

Taxa	Species	Presence	Abundance	Description	Images	Notes
Anadenantheroxylon	A. villaurquicense
Astroniumxylon	A. bonplandianum
	A. parabalansae
Curtiembreoxylon	C. poledrii
Gleditsioxylon	G. paramorphoides
Guadua	G. morronei
	G. zuloagae
Laurinoxylon	L. artabeae
Mangroveoxylon	M.areniensis
Menendoxylon	M. vasallensis
Microlobiusxylon	M. paranaensis
Maytenoxylon	M. sp.
Mimosoxylon	M. sp.
Palmoxylon	P. yuqueriense
Prosopisinoxylon	P. americanum
Prumnopityoxylon	P. gnaedingerae
Ruprechtioxylon	R. breae
Scalarixylon	S. sp.
Schinopsixylon	S. heckii
Soroceaxylon	S. entrerriensis
Syagrus	S. sp.
Uruguaianoxylon	U. striata

Icnofossils

Huayquerian correlations

Huayquerian correlations in South America

Formation		Ituzaingó															Map
Basin																	align=center rowspan=17
Cardiatherium	align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center
Lagostomus	align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center
Macroeuphractus	align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center
Proeuphractus	align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center
Pronothrotherium	align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center
Pseudotypotherium	align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center
Thylacosmilus	align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center
Xotodon	align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center
	align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center
	align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center
Rodents	align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center
Reptiles	align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center
Birds	align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center			align=center		align=center		align=center		align=center
Terror birds	align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center
	align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center		align=center
	Aeolian-fluvial	Fluvio-deltaic			Fluvial						Fluvio-lacustrine	Fluvial			Fluvio-lacustrine	Fluvio-deltaic
Volcanic						Yes

See also

• South American land mammal ages
• Honda Group
• Pebas Formation
• Urumaco
• Battle of Ituzaingó

References

Bibliography

• El Neógeno de la Mesopotamia argentina

Notes and References

1. http://www.fossilworks.org/cgi-bin/bridge.pl?action=displayStrata&geological_group=&formation=Ituzaingo&group_formation_member=Ituzaingo Ituzaingó Formation
2. Vezzosi, 2015, p.27
3. Vezzosi, 2015, p.28
4. Vezzosi, 2015, p.29
5. Franco, 2014, p.16
6. Brunetto, 2013, p.22
7. Cione et al., 2000, p.195
8. Cione et al., 2009, p.3
9. Vezzosi, 2015, p.41
10. Vezzosi, 2015, p.75
11. Cione et al., 2005, p.49
12. http://www.fossilworks.org/cgi-bin/bridge.pl?a=collectionSearch&collection_no=140472 Colonia La Celina
13. Torra, 2005, p.46
14. Martín Pérez, 2013, p.291
15. Martín Pérez, 2013, p.27
16. Cione et al., 2005, p.58
17. Brandoni, 2013, p.135