The Ituzaingó Formation ( es, Formación Ituzaingó), in older literature also described as Entre Ríos or Entrerriana Formation, is an extensive

geological formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock expo ...

Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene Epoch made up of two stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million years ago) to 5.333 Ma. The ...

(

Tortonian The Tortonian is in the geologic time scale an age or stage of the late Miocene that spans the time between 11.608 ± 0.005 Ma and 7.246 ± 0.005 Ma (million years ago). It follows the Serravallian and is followed by the Messinian. The Tort ...

, or

Huayquerian The Huayquerian ( es, Huayqueriense) age is a period of geologic time (9.0–6.8 Ma) within the Late Miocene epoch of the Neogene, used more specifically within the SALMA classification. It follows the Mayoan and precedes the Montehermosan age ...

in the SALMA classification) age in the

Paraná Basin The Paraná Basin ( pt, Bacia do Paraná, es, Cuenca del Paraná) is a large cratonic sedimentary basin situated in the central-eastern part of South America. About 75% of its areal distribution occurs in Brazil, from Mato Grosso to Rio Grande ...

of the

Corrientes Corrientes (; Guaraní: Taragüí, literally: "Currents") is the capital city of the province of Corrientes, Argentina, located on the eastern shore of the Paraná River, about from Buenos Aires and from Posadas, on National Route 12. It has ...

, Santa Fe and

Entre Ríos Province Entre Ríos (, "Between Rivers") is a central province of Argentina, located in the Mesopotamia region. It borders the provinces of Buenos Aires (south), Corrientes (north) and Santa Fe (west), and Uruguay in the east. Its capital is Paraná ...

s in

Mesopotamia Mesopotamia ''Mesopotamíā''; ar, بِلَاد ٱلرَّافِدَيْن or ; syc, ܐܪܡ ܢܗܪ̈ܝܢ, or , ) is a historical region of Western Asia situated within the Tigris–Euphrates river system, in the northern part of the F ...

, northeastern

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, t ...

.Ituzaingó Formation
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cre ...

.org The formation comprises mudstones, cross-bedded

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates ...

s and conglomerates deposited in a

fluvio In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or flu ...

- deltaic

environment Environment most often refers to: __NOTOC__ * Natural environment, all living and non-living things occurring naturally * Biophysical environment, the physical and biological factors along with their chemical interactions that affect an organism or ...

and is renowned for the preservation of a rich fossil assemblage, including many mammals,

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

s, reptiles,

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% ...

bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, biv ...

foraminifera Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular ectoplasm for catching food and other uses; and commonly ...

, ichnofossils and

flora Flora (: floras or florae) is all the plant life present in a particular region or time, generally the naturally occurring (indigenous (ecology), indigenous) native plant, native plants. The corresponding term for animals is ''fauna'', and for f ...

Description

The Ituzaingó Formation was first described by De Alba in 1953 and later by Herbst in 1971.Vezzosi, 2015, p.27 The up to , but in most areas between thick formation is found in an area of ,Vezzosi, 2015, p.28 stretching from the

Paraná River The Paraná River ( es, Río Paraná, links=no , pt, Rio Paraná, gn, Ysyry Parana) is a river in south-central South America, running through Brazil, Paraguay, and Argentina for some ."Parana River". Encyclopædia Britannica. Encyclopædia Br ...

to east of Tostado.Vezzosi, 2015, p.29 The Ituzaingó Formation crops out in the northeasternmost part of Argentina (

), in the

provinces A province is almost always an administrative division within a country or state. The term derives from the ancient Roman ''provincia'', which was the major territorial and administrative unit of the Roman Empire's territorial possessions outsi ...

, Santa Fe and Entre Ríos, among other locations along the banks of the

.Franco, 2014, p.16

Stratigraphy

The formation overlies the marine Paraná Formation and is unconformably overlain by the Puerto Alvear,Brunetto, 2013, p.22 Hernandarías and Yupoí Formations of Early Pleistocene ( Uquian and

Ensenadan The Ensenadan age is a period of geologic time (1.2–0.8 Ma) within the Early Pleistocene epoch of the Quaternary used more specifically with South American Land Mammal Ages. It follows the Uquian and precedes the Lujanian The Lujanian age is a ...

respectively) age.Cione et al., 2000, p.195Cione et al., 2009, p.3 At the shores of the Paraná River, the formation underlies the Timbúes Formation.Vezzosi, 2015, p.41 In certain places along the same river, the formation cuts into the underlying Rosario Formation.Vezzosi, 2015, p.75 The formation contains a basal conglomeratic member "Conglomerado osífero" (''bony conglomerate'') with abundant vertebrate remains.Cione et al., 2005, p.49 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 Puelche or Puelches may refer to: * Puelche people, an indigenous people of Argentina and Chile *Puelche language Puelche was a language formerly spoken by the Puelche people in the Pampas region of Argentina. The language is also known as ''Gü ...

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

(

) or

in the SALMA classification.Colonia La Celina
at

.org

Depositional environment

The formation, as the Paraná and Puelches Formations, has been deposited in a vast Miocene tidal flat environment.Torra, 2005, p.46 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. Alternatively, the Conglomerado Osífero Member has been interpreted as

tide Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tables can ...

-dominated fluvial channels, pertaining to the marine Paraná Formation.Martín Pérez, 2013, p.291

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.Martín Pérez, 2013, p.27 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 is a Japanese public multinational conglomerate manufacturer of automobiles, motorcycles, and power equipment, headquartered in Minato, Tokyo, Japan. Honda has been the world's largest motorcycle manufacturer since 1959, reaching a product ...

La Venta La Venta is a pre-Columbian archaeological site of the Olmec civilization located in the present-day Mexican state of Tabasco. Some of the artifacts have been moved to the museum "Parque - Museo de La Venta", which is in nearby Villahermos ...

in Colombia, the Urumaco Formation at Urumaco in Venezuela and the Pebas Formation of the Amazon region of Colombia, Ecuador, Peru and Brazil.Cione et al., 2005, p.58 Several

ground sloth Ground sloths are a diverse group of extinct sloths in the mammalian superorder Xenarthra. The term is used to refer to all extinct sloths because of the large size of the earliest forms discovered, compared to existing tree sloths. The Cari ...

genera present in the Ituzaingó Formation are endemic from this unit, whereas other are also present in the

Arroyo Chasicó Formation Arroyo often refers to: * Arroyo (creek), an intermittently dry creek Arroyo may also refer to: People * Arroyo (surname) Places United States ;California * Arroyo Burro Beach, a public beach park in Santa Barbara County, California * Arroyo ...

of Buenos Aires Province, the Andalhuala and

Corral Quemado Formation A pen is an enclosure for holding livestock. It may also perhaps be used as a term for an enclosure for other animals such as pets that are unwanted inside the house. The term describes types of enclosures that may confine one or many anim ...

s of

Catamarca Province Catamarca () is a province of Argentina, located in the northwest of the country. The province had a population of 334,568 as per the , and covers an area of 102,602 km2. Its literacy rate is 95.5%. Neighbouring provinces are (clockwise, fr ...

, and the Toro Negro Formation of La Rioja Province.Brandoni, 2013, p.135

Huayquerian correlations

References

Bibliography

* ''El Neógeno de la Mesopotamia argentina'' ** ** ** ** ** * * * * * * * * * * * * * * * * * * * * *