Yecua Formation

Yecua Formation
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
Other	Gypsum
Location
Region	Chaco Basin
Country	Bolivia

UnderliesTariquia Formation

OverliesPetaca Formation

Thickness~50–300 m (160–980 ft)

PrimaryMudstone, Sandstone^[1]

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]

[1]

[2]

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

Name	Species	Member	Material	Notes
cf. Gyrodes or Natica sp.^[1]
cf. Turritella^[1]	cf. T. sp

Name	Species	Member	Material	Notes
Bythocypris^[1]	B. sp
Cyprideis^[1]	C. sp
cf. Balanus^[1]	cf. B. sp
indetermined crabs ^[1]

Name	Species	Material	Notes
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

Yecua Formation

Gastropods

Crustaceans

Vertebrates

References

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