Río Colorado Subgroup Explained

Río Colorado Subgroup
Type:	Subgroup
Period:	Campanian
Age:	Santonian-Early Campanian ~
Prilithology:	Mudstone, sandstone
Otherlithology:	Siltstone, limestone
Region:	Neuquén & Río Negro Provinces
Coordinates:	-37.9°N -68.5°W
Paleocoordinates:	-40.8°N -53°W
Unitof:	Neuquén Group
Subunits:	Anacleto & Bajo de la Carpa Formations
Underlies:	Malargüe Group  Allen Formation
Overlies:	Río Neuquén Subgroup  Plottier Formation
Thickness:	Up to 240m (790feet)
Extent:	Neuquén Basin

The Río Colorado Subgroup, formerly named as Río Colorado Formation, is a Late Cretaceous (Santonian to Early Campanian) geologic subgroup of the Neuquén Basin in northern Patagonia, Argentina. It belongs to the Neuquén Group and contains the Anacleto and Bajo de la Carpa Formations. The subgroup overlies the Río Neuquén Subgroup and is overlain by the Allen Formation of the Malargüe Group, separated by an unconformity dated to 79 Ma.^[1] Dinosaur remains diagnostic to the genus level are among the fossils that have been recovered from the formation.^[2]

Fossil content

Sauropods

Titanosaur eggs are known from Neuquén Province.^[5]

Sauropods reported from the Río Colorado Subgroup
Genus	Species	Province	Stratigraphic position	Material	Notes	Images
Antarctosaurus	A. wichmannianus	Río Negro Province	Anacleto Formation
Bonatitan	B.reigi	Río Negro Province	Allen Formation
Loricosaurus^[6]	L. scutatus	Neuquén Province Río Negro Province
Microcoelus	M. patagonicus	Neuquén Province	Bajo de la Carpa Formation		Possible synonym of Neuquensaurus
Neuquensaurus	N. australis	Neuquén Province Río Negro Province	Anacleto Formation
"Titanosaurus"	"T." robustus	Río Negro Province	Anacleto Formation
Titanosaurus^[7]	T. nanus	Neuquén Province	Bajo de la Carpa Formation

Theropods

Theropods reported from the Río Colorado Subgroup
Genus	Species	Province	Stratigraphic position	Material	Notes	Images
Abelisaurus	A. comahuaensis	Río Negro Province	Anacleto Formation	"Partial skull."^[8]
Alvarezsaurus	A. calvoi	Neuquén Province	Bajo de la Carpa Formation	"Partial postcranial skeleton."^[9]
Aucasaurus	A. garridoi	Neuquén Province	Anacleto Formation	"Nearly complete skeleton."
Neuquenornis	N. volans	Neuquén Province	Bajo de la Carpa Formation	"Partial skeleton."^[10]
Patagopteryx	P. deferrariisi	Neuquén Province	Bajo de la Carpa Formation	"Many skeletons."^[11]
Velocisaurus	V. unicus	Neuquén Province	Bajo de la Carpa Formation	"Partial hind limb."

See also

• List of stratigraphic units with dinosaur body fossils
• List of stratigraphic units with dinosaur trace fossils

References

Bibliography

Notes and References

1. Leanza et al., 2004, p.63
2. Weishampel et al., 2004, pp. 603-604
3. "63.10 Provincia de Río Negro, Argentina; 4. Río Colorado Formation," in Weishampel, et al. (2004). Page 604.
4. "Table 18.1," in Weishampel, et al. (2004). Page 395.
5. "63.6 Provincia de Neuquén, Argentina; 3. Río Colorado Formation," in Weishampel, et al. (2004). Page 603.
6. Listed as "?Loricosaurus scutatus" in "63.6 Provincia de Neuquén, Argentina; 3. Río Colorado Formation" and "63.10 Provincia de Río Negro, Argentina; 4. Río Colorado Formation," in Weishampel, et al. (2004). Pages 603-604.
7. "63.6 Provincia de Neuquén, Argentina; 3. Río Colorado Formation" and "63.10 Provincia de Río Negro, Argentina; 4. Río Colorado Formation," in Weishampel, et al. (2004). Pages 603-604.
8. "Table 3.1," in Weishampel, et al. (2004). Page 49.
9. "Table 11.1," in Weishampel, et al. (2004). Page 211.
10. "Table 11.1," in Weishampel, et al. (2004). Page 213.
11. "Table 11.1," in Weishampel, et al. (2004). Page 212.