Yecua Formation
Geologic formation in Bolivia
Yecua Formation | |
---|---|
Stratigraphic range: Late Langhian-Early Messinian (Colloncuran-Huayquerian) ~14–7 Ma PreꞒ Ꞓ O S D C P T J K Pg N | |
Underlies | Tariquia Formation |
Overlies | Petaca Formation |
Thickness | ~50–300 m (160–980 ft) |
Lithology | |
Primary | Mudstone, Sandstone[1] |
Other | Gypsum |
Location | |
Region | Chaco Basin |
Country | ![]() |
The Yecua Formation is a geological Formation in what is now Bolivia. Studies suggest that the Yecua Formation preserves a coastal setting with humid to semiarid floodplains, shorelines and tidal as well as shallow marine environments including marshes, streams, lakes and brackish bodies of water. There may have been a connection to the Amazon Basin or the Paranaense Sea.[2]
Bivalves
Name | Species | Member | Material | Notes |
---|---|---|---|---|
Tellina[1] | T. sp | |||
cf. Cyrena[1] | cf. C. sp | |||
cf. Astarte[1] | cf. A. sp | |||
cf. Lucina[1] | cf. L. sp | |||
Senis[1] | S. cf. elongatus | |||
cf. Corbula or Cymbophora sp.[1] | cf. C. sp | |||
cf. Nucula[1] | cf. N. sp |
Gastropods
Name | Species | Member | Material | Notes |
---|---|---|---|---|
cf. Gyrodes or Natica sp.[1] | ||||
cf. Turritella[1] | cf. T. sp |
Crustaceans
Name | Species | Member | Material | Notes |
---|---|---|---|---|
Bythocypris[1] | B. sp | |||
Cyprideis[1] | C. sp | |||
cf. Balanus[1] | cf. B. sp | |||
indetermined crabs [1] |
Vertebrates
Name | Species | Member | Material | Notes | Image |
---|---|---|---|---|---|
cf. Theosodon[1] | cf. T. sp | distal limb bone | a litoptern | ![]() | |
Rodentia indet.[1] | tooth | ||||
Mourasuchus[3] | M. sp. | skull fragments, partial vertebrae & ribs | |||
Pleurodira[3] | shell elements | ||||
Humboldtichthys[4] | Humboldtichthys kirschbaumi | incompletely preserved anterior portion of the body and posterior head | a Glass Knifefish | ||
Siluriformes indet.[1] | possibly Ariidae | ||||
Characiformes or Clupeiformes[1] | a scale |
References
- ^ a b c d e f g h i j k l m n o p q r Marshall, L.G.; Sempere, T.; Gayet, M. (1993). "The Petaca (Late Oligocene - Middle Miocene) and Yecua (Late Miocene) Formations of the Subandean-Chaco Basin, Bolivia, and their Tectonic Significance". Travaux et Documents des Laboratoires de Géologie de Lyon. 125: 291–301.
- ^ Hulka, C.; Gräfe, K.U.; Sames, B.; Uba, C.E.; Heubeck, C. (2006). "Depositional setting of the Middle to Late Miocene Yecua Formation of the Chaco Foreland Basin, southern Bolivia". Journal of South American Earth Sciences. 21 (1–2): 135–150. Bibcode:2006JSAES..21..135H. doi:10.1016/j.jsames.2005.08.003.
- ^ a b Tineo, D.E.; Bona, P.; Pérez, L.M.; Vergani, G.D.; González, G.; Poiré, D.G.; Gasparini, Z.; Legarreta, P. (2015). "Palaeoenvironmental implications of the giant crocodylian Mourasuchus (Alligatoridae, Caimaninae) in the Yecua Formation (late Miocene) of Bolivia". Alcheringa. 39 (2): 1–12. Bibcode:2015Alch...39..224T. doi:10.1080/03115518.2015.967162. hdl:11336/33274. S2CID 129930697.
- ^ Albert, J.S.; Fink, W.L. (2010). "Phylogenetic relationships of fossil neotropical electric fishes (Osteichthyes: Gymnotiformes) from the upper Miocene of Bolivia". Journal of Vertebrate Paleontology. 27 (1): 17–25. doi:10.1671/0272-4634(2007)27[17:PROFNE]2.0.CO;2. S2CID 35007130.