Enciso Group

Enciso Group
Enciso Group
Stratigraphic range: Hauterivian-early Aptian; ~135–118 Ma PreꞒ Ꞓ O S D C P T J K Pg N
	Ichnofossils near Enciso
Type	Geologic group
Sub-units	Leza & Jubela Formations
Underlies	Oliván Group
Overlies	Urbión Group
Lithology
Primary	Sandstone, limestone
Other	Marl, mudstone
Location
Coordinates	42°06′N 2°18′W / 42.1°N 2.3°W
Approximate paleocoordinates	31°42′N 9°00′E / 31.7°N 9.0°E
Region	La Rioja
Country	Spain
Extent	Cameros Basin
Type section
Named for	Enciso, La Rioja
	Enciso Group (Spain) Enciso Group (La Rioja, Spain)

The Enciso Group is a geological formation in La Rioja, Spain whose strata date back to the Early Cretaceous.

The turtle Camerochelys was described from the Enciso Group. Dinosaur remains, including the holotype of the spinosaurid Riojavenatrix, are among the fossils that have been recovered from the formation.

The first spinosaurid fossil remains found at Igea, Enciso Group were a jaw fragment found in 1983 and isolated teeth.

Description

The Cameros Basin containing the Enciso Group represents continental synrift deposition. It consists of carbonate and siliciclastic lacustrine deposits. Cobble to boulder-sized dropstones and sand to silt sized IRD were observed in three different lithofacies. These are restricted glaciolacustrine shales, laminated glaciolacustrine silts, and proglacial sandy lobes correlated to glacier front retreat. This deep glacial lake system is compared favourably lacustrine sediment sequences related to Pleistocene glacial cycles of the Laurentide Ice Sheet in the eastern Canadian Arctic. This along with other evidence of cryospheric activity suggested extensive continental ice sheets during the Hauterivian Cold Snap.

Fossil content

The following fossils have been found in the formation:

Color key

Taxon	Reclassified taxon	Taxon falsely reported as present	Dubious taxon or junior synonym	Ichnotaxon	Ootaxon	Morphotaxon

Notes
Uncertain or tentative taxa are in small text
~~crossed out~~ taxa are discredited.

Dinosaurs

Ornithischians

Ornithischians of the Enciso Group
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Styracosterna Indet.	Indeterminate

Theropods

Theropods of the Enciso Group
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Riojavenatrix	R. lacustris				A baryonychine spinosaurid

Turtles

Turtles of the Enciso Group
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Camerochelys	C. vilanovai				A xinjiangchelyid turtle

References

↑ Enciso Group at Fossilworks.org
↑ Rodríguez-López, Juan Pedro; Liesa, Carlos L.; Luzón, Aránzazu; Muñoz, Arsenio; Mayayo, María J.; Murton, Julian B.; Soria, Ana R. (2023-10-10). "Ice-rafted dropstones at midlatitudes in the Cretaceous of continental Iberia". Geology. 52 (1): 33–38. doi:10.1130/G51725.1. ISSN 0091-7613.
↑ Weishampel et al., 2004, pp. 556-563
↑ García-Palou, J.; Isasmendi, E.; Torices, A. (2025). "An analysis of the first fossil remains of styracosternan ornithopod dinosaurs from the Early Cretaceous of La Rioja (Spain) and its paleobiogeographical implications". Palaeontologia Electronica. 28 (2) 28.2.a34. doi:10.26879/1364.
↑ Isasmendi, E.; Cuesta, E.; Díaz-Martínez, I.; Julio Company; Sáez-Benito, P.; Viera, L. I.; Torices, A.; Pereda-Suberbiola, Xabier (2024). "Increasing the theropod record of Europe: a new basal spinosaurid from the Enciso Group of the Cameros Basin (La Rioja, Spain). Evolutionary implications and palaeobiodiversity". Zoological Journal of the Linnean Society. 202 (3) zlad193. doi:10.1093/zoolinnean/zlad193.
↑ A. Pérez-García; F.-R. Sáez-Benito; X. Murelaga (2017). "New information on the anatomy and systematics of the Spanish Lower Cretaceous Camerochelys vilanovai (Testudines, Pan-Cryptodira)". Journal of Iberian Geology. 43 (2): 147–154. doi:10.1007/s41513-017-0014-6. S2CID 133741760.

Bibliography

Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (2004), The Dinosauria, 2nd edition, Berkeley: University of California Press, pp. 1–880, ISBN 0-520-24209-2, retrieved 2019-02-21{{citation}}: CS1 maint: publisher location (link)

M. Melero Rubio and F. Pérez Lorente. 2011. Huellas en las obras. Reconocimiento y estudio de huellas fo?siles de dinosaurio en las obras de la presa de Enciso (La Rioja. Espan?a) [Footprints in the works. Recognition and study of fossil dinosaur footprints in the works of the Enciso dam (La Rioja. Spain)]. Zubía 29:31-60
A. Pérez García, X. Murelaga, J. A. Torres, L. I. Viera, and F.-R. Sáez Benito. 2010. Tortugas del Cretácico Inferior (Hauteriviense–Barremiense) de La Rioja (Cuenca de Cameros, España) [Turtles from the Lower Cretaceous (Hauterivian–Barremian) of La Rioja (Cameros Basin, Spain)]. Geogaceta 48:87-90
I. Díaz Martínez, F. Pérez Lorente, X. Pereda Suberbiola and J. I. Canudo. 2009. Iguanodon-like footprints from the Enciso Group (Aptian, Lower Cretaceous) of La Rioja (Cameros Basin, Spain). In P. Godefroit & O. Lambert (ed.), Tribute to Charles Darwin and Bernissart Iguanodons: New Perspectives on Vertebrate Evolution and Early Cretaceous Ecosystems. Programme, Abstracts and Field Trips Guidebook 34
A. Jiménez Vela and F. Pérez Lorente. 2007. El Corral del Totico. Dos nuevos yacimientos con pistas singulares. (Enciso, La Rioja, España) [El Corral del Totico. Two new localities with unique tracks. (Enciso, La Rioja, Spain)]. Zubía Monográfico 18–19:115-144
L. E. Requeta Loza, N. Hernández Medrano, and F. Pérez Lorente. 2007. La Pellejera: descripción y aportaciones. heterocronía y variabilidad de un yacimiento con huellas de dinosaurio de La Rioja (España) [La Pellejera: description and contributions: heterochrony and variability of a dinosaur footprint locality from La Rioja (Spain)]. Zubia Monográfico 18–19:21-114
F. Pérez Lorente and A. Jiménez Vela. 2007. Barranco de Valdegutiérrez: un nuevo gran yacimiento de huellas de dinosaurio en La Rioja (España) [Barranco de Valdegutiérrez: a new large dinosaur footprint locality in La Rioja (Spain)]. Zubia Monográfico 18–19:9-20
F. Pérez Lorente. 2002. La distribución de yacimientos y de tipos de huellas de dinosaurios en la Cuenca de Cameroa (La Rioja, Burgos, Soria, España) [The distribution of localities and types of dinosaur footprints in the Cameros Basin (La Rioja, Burgos, Soria, Spain)]. Zubia Monográfico 14:191-210
M. Blanco, S. Caro, A. López, F. Pérez Lorente, E. Requeta and M. Romero. 2000. El yacimiento de icnitas de dinosaurio del Cretácico Inferior de Las Losas (Enciso, La Rioja, España) [The Lower Cretaceous dinosaur footprint locality of Las Losas (Enciso, La Rioja, Spain)]. Zubía 18:97-138
M. L. Casanovas, A. Fernández, F. Pérez Lorente and J. V. Santafé. 1997. Sauropod trackways from site El Sobaquillo (Munilla, La Rioja, Spain) indicate amble walking. Ichnos 5:101-107
L. I. Viera and J. A. Torres. 1995. Presencia de Baryonyx walkeri (Saurischia, Theropoda) en el Weald de La Rioja (España). Nota previa [Presence of Baryonyx walkeri (Saurischia, Theropoda) in the Weald of La Rioja (Spain). Previous note]. Munibe 47:57-61
J. J. Moratalla, J. García Mondéjar, V. F. Santos, M. G. Lockley, J. L. Sanz and S. Jiménez. 1995. Sauropod trackways from the Lower Cretaceous of Spain. In M. G. Lockley, V. F. dos Santos, C. A. Meyer, & A. P. Hunt (eds.), Aspects of Sauropod Paleobiology. GAIA 10:75-83
M. L. Casanovas, R. Ezquerra, A. Fernández, F. Pérez Lorente, J. V. Santafé and F. Torcida. 1995. Huellas de dinosaurio en la Era del Peladillo 3 (La Rioja, España). Primera nota [Dinosaur tracks in the Era del Peladillo 3 (La Rioja, Spain). First notice]. Zubía 13:83-101
M. L. Casanovas Cladellas, R. Ezquerra Miguel, A. Fernández Ortega, F. Pérez Lorente, J. V. Santafé Llopis and F. Torcida Fernández. 1994. Tracks of a herd of webbed ornithopods and other footprints found in the same site (Igea, La Rioja, Spain). Revue de Paléobiologie, Volume spéciale 7:29-36
J. J. Moratalla, J. L. Sanz, S. Jimenez and M. G. Lockley. 1992. A quadrupedal ornithopod trackway from the Lower Cretaceous of La Rioja (Spain): inferences on gait and hand structure. Journal of Vertebrate Paleontology 12(2):150-157
M. L. Casanovas, R. Ezquerra, A. Fernández, F. Pérez Lorente, J. V. Santafé and F. Torcida. 1992. Un grupo de saurópodos en el yacimento soto 2. La Rioja (España) [A group of sauropods in locality Soto 2. La Rioja (Spain)]. Zubía 10:45-52
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M. L. Casanovas Cladellas, F. Perez Lorente, J. V. Santafé Llopis and A. Fernández Ortega. 1985. Neuvos datos icnológicos del Cretácico inferior de la Sierra de Cameros (La Rioja, España) [New ichnological data from the Lower Cretaceous of Sierra de Cameros (La Rioja, Spain)]. Paleontologia i Evolució 19:3-18
L. I. Viera, J. A. Torres, and L. M. Aguirrezabala. 1984. El Weald de Munilla (La Rioja) y sus icnitas de dinosaurios. (II) [The Wealden of Munilla (La Rioja) and its dinosaur footprints. (II)]. Munibe 36:3-22
M. L. Casanovas Cladellas and J.-V. Santafé Llopis. 1974. Dos nuevos yacimientos de icnitas de Dinosaurios [Two new dinosaur footprint localities]. Acta Geològica Hispànica 9(3):88-91
M. L. Casanovas Cladellas and J.-V. Santafé Llopis. 1971. Icnitas de reptiles mesozoicos en la provincia de Logroño [Mesozoic reptile footprints in Logroño province]. Acta Geològica Hispànica 6(5):139-142

[FWEnciso-1] Enciso Group at Fossilworks.org

[2] Rodríguez-López, Juan Pedro; Liesa, Carlos L.; Luzón, Aránzazu; Muñoz, Arsenio; Mayayo, María J.; Murton, Julian B.; Soria, Ana R. (2023-10-10). "Ice-rafted dropstones at midlatitudes in the Cretaceous of continental Iberia". Geology. 52 (1): 33–38. doi:10.1130/G51725.1. ISSN 0091-7613.

[cretaceousdistribution-3] Weishampel et al., 2004, pp. 556-563

[4] García-Palou, J.; Isasmendi, E.; Torices, A. (2025). "An analysis of the first fossil remains of styracosternan ornithopod dinosaurs from the Early Cretaceous of La Rioja (Spain) and its paleobiogeographical implications". Palaeontologia Electronica. 28 (2) 28.2.a34. doi:10.26879/1364.

[5] Isasmendi, E.; Cuesta, E.; Díaz-Martínez, I.; Julio Company; Sáez-Benito, P.; Viera, L. I.; Torices, A.; Pereda-Suberbiola, Xabier (2024). "Increasing the theropod record of Europe: a new basal spinosaurid from the Enciso Group of the Cameros Basin (La Rioja, Spain). Evolutionary implications and palaeobiodiversity". Zoological Journal of the Linnean Society. 202 (3) zlad193. doi:10.1093/zoolinnean/zlad193.

[6] A. Pérez-García; F.-R. Sáez-Benito; X. Murelaga (2017). "New information on the anatomy and systematics of the Spanish Lower Cretaceous Camerochelys vilanovai (Testudines, Pan-Cryptodira)". Journal of Iberian Geology. 43 (2): 147–154. doi:10.1007/s41513-017-0014-6. S2CID 133741760.