Santa Lucía Formation

The Santa Lucía Formation is a Maastrichtian to Paleocene (Danian) geologic formation in Bolivia. Fossil ornithopod tracks have been reported from the Cretaceous lower part of the formation.^[1] It is the type formation of the Tiupampan South American land mammal age.

Santa Lucía Formation
Stratigraphic range: Maastrichtian-Paleocene (typically Tiupampan) ~67–62 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Geological formation
Unit of	Potosí Basin
Underlies	Cayara Formation
Overlies	El Molino Formation
Thickness	381.35 m (1,251.1 ft)
Lithology
Primary	Shale, marl
Other	Siltstone
Location
Coordinates	18°00′46.0″S 65°24′23.4″W
Region	Cochabamba
Country	Bolivia
Type section
Location	Tiupampa, Mizque
Coordinates	18°00′46.0″S 65°24′23.4″W
Approximate paleocoordinates	20.7°S 52.5°W / -20.7; -52.5
Santa Lucía Formation (Bolivia)

Description

Paleogeography of Northern South America
65 Ma, by Ron Blakey

The Santa Lucía Formation is a formation of the Potosí Basin in Bolivia dated to the Paleocene, 60 to 58.2 Ma.^[2] It overlies the Cretaceous El Molino Formation and is overlain by the Cayara Formation. The formation is laterally equivalent with the Maíz Gordo Formation of northern Argentina,^[3] and time-equivalent with the Salamanca Formation of Argentina, the Maria Farinha Formation of the Paraíba Basin in northern Brazil and the Guaduas Formation of the Altiplano Cundiboyacense and fossiliferous Cerrejón Formation of the Cesar-Ranchería Basin, Colombia.

The 381.35 metres (1,251.1 ft) thick formation consists of reddish sandy shales, marls and siltstones deposited in a fluvial to lacustrine environment.^[4][5]

Paleontological significance

The oldest known "condylarth" fauna of the Tertiary of South America comes from basal Paleocene strata of the Santa Lucía Formation at Tiupampa. It includes five genera and seven species: Molinodus suarez, Tiuclaenus minutus, T. cotasi, T. robustus, Pucanodus gagnieri, Andinodus boliviensis, and Simoclaenus sylvaticus.^[6] Because of its unique fauna, the Santa Lucía Formation at Tiupampa has been chosen as the earliest South American land mammal age giving rise to the Tiupampan.

At the Parotani tracksite, poorly preserved ichnofossils were found in the Maastrichtian part of the formation, left possibly by a carnosaur.^[7]

Fossil content

The fossiliferous formation has provided the following fossils:

Group	Fossils	Notes
Mammals	Alcidedorbignya inopinata, Allqokirus australis, Andinodelphys cochabambensis, Andinodus boliviensis, Incadelphys antiquus, Jaskhadelphys minutus, Khasia cordillerensis, Kollpania tiupampina, Mayulestes ferox, Mizquedelphys pilpinensis, Molinodus suarezi, Peradectes austrinum, Pucadelphys andinus, Pucanodus gagnieri, Roberthoffstetteria nationalgeographica, Simoclaenus sylvaticus, Szalinia gracilis, Tiulordia floresi, Tiuclaenus minutus, Cimolestes sp., Didelphoidea indet., Henricosborniidae or Oldfieldthomasiidae, Proteutheria indet.	[8][9]
Reptiles & amphibians	Coniophis sp., Cynodontosuchus cf. rothi, Estesiella boliviensis, Kataria anisodonta, Lapparentemys vilavilensis, Podocnemis ?brasiliensis, Roxochelys cf. vilavilensis, Zulmasuchus querejazus, Aniliidae, Boidae, ?Madtsoiidae, Tropidophiidae, Gymnophiona, Carnosauria indet., Ornithopoda indet.	[8][9][10] [11][12] [13]
Fishes	Andinichthys bolivianensis, Dajetella sudamericana, Enchodus oliveirai, Gasteroclupea branisai, Hoffstetterichthys pucai, Incaichthys suarezi, Lepidosiren cf. paradoxa, Phareodusichthys tavernei, Eohiodon sp., Hoplias sp., Lepisosteus sp., Miletes sp., Percichthys sp., Phareodus sp., Rhineastes sp., Rhodsia sp., Ictaluridae indet.	[8][9]

See also

• List of dinosaur-bearing rock formations
  • List of stratigraphic units with ornithischian tracks
    • Ornithopod tracks