Blesa Formation

Blesa Formation
Stratigraphic range: Barremian

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Blesa Formation; Stratigraphic range: Barremian PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Geological formation
Unit of	Maestrazgo Basin
Sub-units	Upper Blesa Sequence - Valdejunco Member; Middle Blesa Sequence - Josa Member; Lower Blesa Sequence - Cabezo Gordo Member, Morenillo member;
Underlies	Alacón Formation
Overlies	Unconformity with Jurassic strata
Thickness	Up to 150 m
Lithology
Primary	Clay, Marl, Limestone
Other	Conglomerate
Location
Region	Europe
	; Distribution of the Belsa Formation within the Oliete Sub-Basin (in olive)

The Blesa Formation is a geological formation in Teruel and La Rioja, Spain whose strata date back to the Barremian of the Early Cretaceous.^[1] Dinosaur remains as well as eggs^[2] are among the fossils that have been recovered from the formation.^[3] Along with the fragmentary anhanguerian pterosaur Iberodactylus.^[4] While the lower and upper parts of the formation were deposited in a continental setting, the middle portion of the formation is largely nearshore marine, with remains of plesiosaurs.

Stratigraphy and Lithology[]

The Belsa Formation is found within the Maestrazgo Basin. Within the stratigraphic sequence it overlies Jurassic rocks in a syn-rift unconformity, and underlies the Alacón Formation.

The formation is up to 150 metres thick and is divided into three distinct unconformity bounded units, which are called the Lower, Middle and Upper Blesa Sequences. The Lower Blesa sequence varies greatly in thickness from less than 10 m up to 100 m is divided up into two members, the lower Cabezo Gordo Member, which consists of red clays and the upper Morenillo Member, which consists of limestones and marls, both of these sequences were deposited in a continental setting. The Middle Blesa Sequence is of a fairly uniform 25-50 metre thickness. Most of the sequence consists of the Josa Member, which consists of oyster rich marls and limestones deposited in a coastal or shallow restricted bay environment. The Upper Blesa Sequence is of variable thickness from 15–70 m. The lower 1–10 m consists of continentally derived clays and marls with sandstone and conglomerate intercalations while the upper 10–60 m are dominated by carbonates.^[1]

Vertebrate paleofauna[]

Reptiles[]

Reptiles of the Blesa Formation
Taxa	Species	Presence	Material	Notes	Images
Iguanodontia	Indeterminate	Lower Blesa Sequence		3 distinct taxa, one of which has affinities with Delapparentia
Ankylosauria	Indeterminate	Lower Blesa Sequence	"Isolated teeth, dermal plates and vertebra"
Spinosauridae	Indeterminate	Lower, Upper Blesa Sequence	Isolated Teeth
Dromaeosauridae	Indeterminate	Lower Blesa Sequence	Isolated Teeth
?Carcharodontosauridae	Indeterminate	Lower, Upper Blesa Sequence	Isolated Teeth
Euhelopidae	Indeterminate	Lower Blesa Sequence	Isolated Teeth
Sauropoda	Indeterminate	Lower Blesa Sequence, La Cantalera-1	Post-cranial material
Crocodylomorpha	Indeterminate	Lower Blesa Sequence		Possibly four distinct taxa
Plesiosauria	Indeterminate	Middle Blesa Sequence

Pterosaurs[]

Pterosaurs of the Blesa Formation
Taxa	Species	Presence	Material	Notes	Images
Istiodactylidae	Indeterminate	Lower Blesa Sequence	Isolated Teeth
Ornithocheiridae	Indeterminate	Lower Blesa Sequence	Isolated Teeth
Iberodactylus	I. andreui	Middle Blesa Sequence	Partial skull

Mammals[]

Mammals of the Blesa Formation
Taxa	Species	Presence	Material	Notes	Images
	C. abadi	Lower Blesa Sequence	Teeth	Pinheirodontid
Eobataar	Indeterminate	Lower Blesa Sequence	Teeth

Correlation[]

Early Cretaceous stratigraphy of Iberia
Ma	Age	Paleomap \ Basins		Olanyà								Lusitanian
100	Cenomanian											Caranguejeira


125	Albian		-
			Monte Grande		Escucha		Escucha
			-		Escucha
	Aptian		-		- Castrillo
			-		En Gp. -	Morella/			Morella
			-		En Gp. -	Forcall					Upper Bedoulian
	Barremian					Xert	Alacón	Xert		Huérguina	Upper Bedoulian
						Artoles				Collado		Papo Seco
				Rúbies	Tera Gp. -	Alacón/Blesa	Blesa	Camarillas		Collado		Papo Seco
150	Hauterivian				Ur Gp. -		Blesa	Castellar	Tera Gp. -
							hiatus

	Valanginian				Ur Gp. -				-
					-				- Piedrahita

	Berriasian		-			hiatus
					- Rupelo			Arzobispo	hiatus
					On Gp. -			Arzobispo
	Tithonian		Lastres		Tera Gp. -		Higuereles			Tera Gp. -		Lourinhã
					Tera Gp. -				Arzobispo
									Arzobispo
Legend		Major fossiliferous, oofossiliferous, ichnofossiliferous, coproliferous, minor formation
Sources

References[]

^ ^a ^b Aurell, M.; Soria, A. R.; Bádenas, B.; Liesa, C. L.; Canudo, J. I.; Gasca, J. M.; Moreno-Azanza, M.; Medrano-Aguado, E.; Meléndez, A. (June 2018). "Barremian synrift sedimentation in the Oliete sub-basin (Iberian Basin, Spain): palaeogeographical evolution and distribution of vertebrate remains". Journal of Iberian Geology. 44 (2): 285–308. doi:10.1007/s41513-018-0057-3. ISSN 1698-6180.
^ Moreno-Azanza, Miguel; Canudo, José Ignacio; Gasca, José Manuel (September 2014). "Spheroolithid eggshells in the Lower Cretaceous of Europe. Implications for eggshell evolution in ornithischian dinosaurs". Cretaceous Research. 51: 75–87. doi:10.1016/j.cretres.2014.05.017. ISSN 0195-6671.
^ Weishampel, David B; et al. (2004). "Dinosaur distribution (Early Cretaceous, Europe)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. p. 561. ISBN 0-520-24209-2.
^ Holgado, Borja; Pêgas, Rodrigo V.; Canudo, José Ignacio; Fortuny, Josep; Rodrigues, Taissa; Company, Julio; Kellner, Alexander W. A. (December 2019). "On a new crested pterodactyloid from the Early Cretaceous of the Iberian Peninsula and the radiation of the clade Anhangueria". Scientific Reports. 9 (1): 4940. doi:10.1038/s41598-019-41280-4. ISSN 2045-2322. PMC 6426928. PMID 30894614.

[:0-1] Aurell, M.; Soria, A. R.; Bádenas, B.; Liesa, C. L.; Canudo, J. I.; Gasca, J. M.; Moreno-Azanza, M.; Medrano-Aguado, E.; Meléndez, A. (June 2018). "Barremian synrift sedimentation in the Oliete sub-basin (Iberian Basin, Spain): palaeogeographical evolution and distribution of vertebrate remains". Journal of Iberian Geology. 44 (2): 285–308. doi:10.1007/s41513-018-0057-3. ISSN 1698-6180.

[2] Moreno-Azanza, Miguel; Canudo, José Ignacio; Gasca, José Manuel (September 2014). "Spheroolithid eggshells in the Lower Cretaceous of Europe. Implications for eggshell evolution in ornithischian dinosaurs". Cretaceous Research. 51: 75–87. doi:10.1016/j.cretres.2014.05.017. ISSN 0195-6671.

[cretaceousdistribution-3] Weishampel, David B; et al. (2004). "Dinosaur distribution (Early Cretaceous, Europe)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. p. 561. ISBN 0-520-24209-2.

[4] Holgado, Borja; Pêgas, Rodrigo V.; Canudo, José Ignacio; Fortuny, Josep; Rodrigues, Taissa; Company, Julio; Kellner, Alexander W. A. (December 2019). "On a new crested pterodactyloid from the Early Cretaceous of the Iberian Peninsula and the radiation of the clade Anhangueria". Scientific Reports. 9 (1): 4940. doi:10.1038/s41598-019-41280-4. ISSN 2045-2322. PMC 6426928. PMID 30894614.

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