| Santiago Formation | |
|---|---|
| Stratigraphic range: Sandbian-Katian ~ | |
| Type | Geological formation |
| Lithology | |
| Primary | Siltstone |
| Location | |
| Coordinates | 18°00′S65°00′W / 18.0°S 65.0°W |
| Approximate paleocoordinates | 45°24′S128°30′W / 45.4°S 128.5°W |
| Region | Cochabamba Department |
| Country |  Bolivia |
| Extent | Cordillera Oriental |
  Santiago Formation, Bolivia (Bolivia) | |
The Santiago Formation is a Sandbian to Katian geologic formation of central Bolivia. The formation comprises gray quartzitic siltstones. [1]
The formation has provided the following fossils:
Zulmasuchus is an extinct genus of sebecid sebecosuchian mesoeucrocodylian. Its fossils have been found in Early Paleocene-age rocks of the Santa Lucía Formation in Bolivia. Zulmasuchus was named in 2007 by Alfredo Paolillo and Omar Linares for fossils originally described by Buffetaut and Marshall in 1991 as Sebecus querejazus. Thus, the type species is Sebecus querezajus and the combinatio nova is Zulmasuchus querejazus.
Dolichochampsa is an extinct genus of eusuchian crocodylomorph. It is the type genus and only member of the family Dolichochampsidae. Fossils have been found in the Yacoraite Formation of Argentina and the El Molino Formation of Bolivia of Maastrichtian age. It had a distinctive slender snout. Because the material associated with the specimens is so fragmentary, its relationships with other eusuchians remain unknown. Jouve et al. (2020) assigned Dolichochampsa to Gavialoidea, making it the oldest known South American member of this clade.
The Chacarilla Formation is an Oxfordian to Early Cretaceous geologic formation of the Tarapacá Basin in northern Chile, close to the border with Bolivia. The marine and fluvial formation preserves several dinosaur trackways and has been declared a Natural Sanctuary in 2004.
The Malargüe Group is a group of geologic formations of the Neuquén Basin of the Mendoza, Neuquén, Río Negro and La Pampa Provinces in northern Patagonia, Argentina. The formations of the Malargüe Group range in age between the middle Campanian to Deseadan, an Oligocene age of the SALMA classification, straddling the Cretaceous–Paleogene boundary, about 79 million to 30 million years in age. The group overlies the older Neuquén Group, separated by an unconformity dated to 79 Ma. The rocks of the Malargüe Group comprise both marine and continental deposits which are over 400 m (1312 ft) thick in total.
Archaeohyrax is a genus of extinct notoungulate mammal known from the Middle Eocene to Oligocene of Argentina and Bolivia.
Santiago Formation may refer to:
Prohegetotherium is an extinct genus of hegetotheriid notoungulates from the Late Oligocene to Early Miocene of the Agua de la Piedra, Mariño & Sarmiento Formations of Argentina, the Petaca and Salla Formations of Bolivia, and Fray Bentos Formation of Uruguay.
The Iscayachi Formation, in older literature also referred to as Guanacuno Formation, is an extensive Tremadocian geologic formation of western and southern Bolivia. The shales and sandstones were deposited in a shallow marine to pro-delta environment. The formation reaches a thickness of 1,000 metres (3,300 ft).
The Pircancha Formation is a Floian to Dapingian geologic formation of southern Bolivia. The green mudstones, shales and sandstones were deposited in a shallow to open marine environment. The fossil Pircanchaspis rinconensis is named after the formation.
The Obispo Formation is a Dapingian geologic formation of southern Bolivia. The shales and siltstones were deposited in an open marine environment.
The San Lorenzo Formation is a Dapingian geologic formation of southern Bolivia. The dark gray, greenish, and black shale with thin intercalations of white-yellow quartzites were deposited in an open marine submarine fan environment.
The Sella Formation is a Dapingian to Darriwilian geologic formation of southern Bolivia. The grey to green bioturbated siltstones interbedded with thin sandstone layers bear lenticular shell beds. Other parts of the formation contain yellow-green limy shales and grey sandy limestones. Coquinas often fill gutter casts and included brachiopods, trilobites, bivalves and nautiloids. The sediments were deposited in an open marine environment. The species Coxiconchia sellaensis was named after the formation.
The San Benito Formation is a Katian geologic formation of central Bolivia. The formation belongs to the Cochabamba Group, overlies the Anzaldo Formation and is overlain by the Cancañiri Formation. The 500 metres (1,600 ft) thick formation comprises a succession of shallow water quartzitic sandstones with minor interbeds of dark grey micaceous siltstones. Shelly fossils have been found at few horizons and consist mainly of linguliformean brachiopods, bivalves, and a few homalonotid trilobite remains. Poorly preserved graptolites occur occasionally in the shaly beds.
The Llallagua Formation is a Rhuddanian to Homerian geologic formation of western Bolivia. The formation comprises siliciclastic sediments. The fossil fauna suggests a warm water, nearshore current was active allowing northern hemisphere benthos to exist in the formation.
The Catavi Formation is a Pridoli to Emsian geologic formation of northern and central Bolivia. The formation comprises a 456 m (1,496 ft) thick succession of fine-grained, olive to brown sandstones and siltstones, shales and black limestones deposited in a shallow to deep marine environment.
The El Molino Formation is a Maastrichtian geologic formation pertaining to the Puca Group of central Bolivia. The formation comprises fine-grained sandstones and sandy limestones with stromatolites deposited in a shallow marine to lacustrine environment. The formation has provided fossils of Dolichochampsa minima, and ichnofossils of Ankylosauria indet., Ornithopoda indet., Theropoda indet. and Titanosauridae indet. The tracksite of Cal Orcko is the best known example of the ichnofossil locations of the formation. The ichnofossil of Ligabueichnum bolivianum may be attributed to an ankylosaur. The fossil fish species Dasyatis molinoensis is named after the formation.
The Anzaldo Formation is a Katian geologic formation of central Bolivia. The formation belongs to the Cochabamba Group, overlies the Capinota Formation and is overlain by the San Benito Formation.
Olisanophus is a genus of extinct litoptern from the late middle Miocene of southern Bolivia. It was named in 2020 by Andrew McGrath and colleagues, for two distinct species from the same deposits of an unnamed formation of the Honda Group. The type species is O. riorosarioensis, known from elements of the partial upper and lower left and right dentitions and possibly a partial mandible, and the referred species is O. akilachuta, known for 6 teeth. Some intermediate material from the same deposits was referred to Olisanophus sp., not showing diagnostic features of either species. Both species were recovered together in a phylogenetic analysis, where they were sister taxa to a group of Diplasiotherium and Mesolicaphrium.
Federicoanaya is an extinct genus of interatheriine notoungulates that lived during the Late Oligocene in what is now Bolivia. Fossils of this genus have been found in the Salla Formation of Bolivia.