The Ituzaingó Formation (), 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.Ituzaingó Formation at Fossilworks.org 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.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 to east of Tostado.Vezzosi, 2015, p.29 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.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 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 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.Colonia La Celina at Fossilworks.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-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 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.Cione et al., 2005, p.58 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.Brandoni, 2013, p.135
Birds Taxa Species Presence Abundance Description Images Notes Andalgalornis A. steulleti DevincenziaD. pozzi MacranhingaM. paranensis M. ranzii Palaelodus P. cf. ambiguus RheaR. (Pterocnemia) mesopotamica Megapaloelodus M. sp. Phoenicopteridae Indeterminate. Phorusrhacidae Indetermidate. Rallidae Indeterminate. Rheidae Indeterminate.
Mammals Chiroptera Taxa Species Presence Abundance Description Images Notes Eumysops E. parodii Notictis N. ortizi
Cetaceans Taxa Species Presence Abundance Description Images Notes SaurocetesS. gigas Iniidae indet.
Litopterns Taxa Species Presence Abundance Description Images Notes Brachytherium B. cuspidatum CulliniaC. sp.DiadiaphorusD. paranensis NeobrachytheriumN. ameghinoiOxyodontheriumO. piramydatusO. zeballosi ParanaucheniaP. denticulata PromacraucheniaP. antiqua ProterotheriumP. cervioides ScalabrinitheriumS. bravardi S. rothii
Marsupials Taxa Species Presence Abundance Description Images Notes PhilanderP. entrerianus ChironectesC. sp. ZygolestesZ. paranensis
Sparassodonts Taxa Species Presence Abundance Description Images Notes Thylacosmilus T. atrox StylocynusS. paranensis
Rodents Taxa Species Presence Abundance Description Images Notes BriaromysB. trouessartianus CardiatheriumC. paranense Carlesia C. pendolaiDiaphoromys D. compressidens D. gamayensis D. mesopotamicusEumegamys E. contortus E. dubius E. scalabrinianus E. paranensisEumegamysopsE. praependensGyriabrus G. glutinatusG. holmbergi G. indivisus G. rebagliattii HaplostrophaH. sacabriniana Isostylomys I. ameghinoi I. laurillardi LagostomopsisL. antiquus L. pallidensMyocastorM. obesusM. paranensisM. sinuataNeoepiblemaN. ambrosettianusN. horridula Olenopsis O. typicus Paradoxomys P. cancrivorus PentastylodonP. racedi PerimysP. scalabrinianusPhoberomys P. burmeisteri PhugatheriumP. cataclisticumPotamarchusP. murinus P. sigmodon ProtabrocomaP. paranensis PseudosigmomysP. paranensis RusconiaR. crassidensTelodontomysT. compressidens Tetrastylus T. aguilari T. diffusus T. laevigatus T. robustus T. (Protelicomys) atavus Cardiomys Caviodon PaleocaviaPliodolichotisProdolichotis
Toxodonts Taxa Species Presence Abundance Description Images Notes Adinotherium ?A. paranense Dinotoxodon D. paranensisEutomodusE. elautusHaplodontheriumH. limun Stenotephanos S. plicidens
Typotheres Taxa Species Presence Abundance Description Images Notes Munyizia M. paranensis ProtypotheriumP. antiquum
Xenarthrans Cingulates Taxa Species Presence Abundance Description Images NotesChasicotatusC. spinozai Comaphorus C. concisus A dubious glyptodont.DasypusD. neogarus Relatives of nine-banded armadillos. Eleutherocercus E. paranensis A glyptodont. Kraglievichia K. paranenseMacroeuphractusM. retususPalaehoplophorusP. antiquus PlohophorusP. paranensis ProeuphractusP. limpidus ProtoglyptodonP. primiformisScirrotheriumS. carinatum Trachycalyptus?T. cingulatus UrotheriumU. interundatumZaedyus?Z. sp.
Ground sloths Taxa Species Presence Abundance Description Images Notes Amphiocnus A. paranense Eomegatherium E. nanum MegabradysM. darwini Megalonychops M. primigenius MesopotamocnusM. brevirostrumNeohapalopsN. rothi OctomylodonO. aversusOrtotheriumO. laticurvatum ParanabradysP. vucetichae Pliomegatherium P. lelongi Pliomorphus P. ameghinoi P. gracilis P. mutilatus P. robustusProlestodonP. antiquus P. paranensis Promegatherium P. parvulum P. smaltatum PromylodonP. paranensis Pronothrotherium P. mirabilis Protomegalonyx P. doellojuradoi P. praecursorPseudoeuryurusP. lelongianusPyramiodontheriumP. sp. RanculcusR. scalabrinianus Scelidotheriidae Indeterminate. SphenotherusS. paranensis Strabosodon S. acuticavus S. obtusicavus Torcellia T. paranense
Other Mammals Taxa Species Presence Abundance Description Images Notes CyonasuaC. Argentina
Reptiles Taxa Species Presence Abundance Description Images NotesCaiman C. australis Different species of the genus Caiman, some of which are still extant. C. cf. yacare C. latriostris C. yacareGryposuchusG. neogaeus A giant extinct gavialid crocodilian. MourasuchusM. arendsi ParanacaimanP. bravardi ParanasuchusP. gasparinae TupinambisT. cf. merianae ParahydraspisP. paranaensis PhrynopsP. cf. geoffroanusTestudoT. paranensis
Fish Taxa Species Presence Abundance Description Images NotesColossomaC. macropomum Megapiranha M. paranensis PotamotrygonP. motoro SquatinaS. dumeril Phractocephalus P. ivy CynodontidaeIndetermidate.
Invertebrates Taxa Species Presence Abundance Description Images NotesProtelphidiumP. tuberculatum Ostrea O. sp.
Microflora Taxa Species Presence Abundance Description Images Notes Anadenantheroxylon A. villaurquicenseAstroniumxylon A. bonplandianum A. parabalansaeCurtiembreoxylonC. poledrii Gleditsioxylon G. paramorphoidesGuaduaG. morronei G. zuloagae Laurinoxylon L. artabeae MangroveoxylonM.areniensis Menendoxylon M. vasallensisMicrolobiusxylonM. paranaensis Maytenoxylon M. sp. Mimosoxylon M. sp. Palmoxylon P. yuquerienseProsopisinoxylonP. americanum Prumnopityoxylon P. gnaedingeraeRuprechtioxylonR. breaeScalarixylonS. sp.SchinopsixylonS. heckii Soroceaxylon S. entrerriensis Syagrus S. sp.UruguaianoxylonU. striata
Icnofossils Taxa Species Presence Abundance Description Images Notes Arenicolites
Huayquerian correlations
+ Huayquerian correlations in South America Formation Cerro Azul Ituzaingó Paraná Camacho Raigón Andalhuala Chiquimil Las Flores Maimará Palo Pebas Muyu Rosa Saldungaray Salicas Urumaco Map Basin Colorado Paraná Hualfín Tontal Andes Salta Amazon Huasi Altiplano BA Velasco Falcón Cardiatherium Lagostomus Macroeuphractus Proeuphractus Pronothrotherium Pseudotypotherium Thylacosmilus Xotodon Macraucheniidae Primates Rodents Reptiles Birds Terror birds Flora Environments 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
Further reading