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.
| Blesa Formation | |
|---|---|
| Stratigraphic range: | |
| Type | Geological formation |
| Unit of | Maestrazgo Basin |
| Sub-units |
|
| 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) | |
Stratigraphy and Lithology edit
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 edit
Reptiles edit
| 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[1] | |||
| Iguanodontia | Unnamed | Upper Blesa Sequence | "Vertebrae, ribs, left illium, partial sacrum, and partial left tibia."[5] | |||
| 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 edit
| 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 edit
| Mammals of the Blesa Formation | ||||||
|---|---|---|---|---|---|---|
| Taxa | Species | Presence | Material | Notes | Images | |
| Cantalera | C. abadi | Lower Blesa Sequence | Teeth | Pinheirodontid | ||
| Eobataar | Indeterminate | Lower Blesa Sequence | Teeth | |||
Correlation edit
See also edit
References edit
- ^ a b c 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. Bibcode:2018JIbG...44..285A. doi:10.1007/s41513-018-0057-3. S2CID 134667628.
- ^ 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. Bibcode:2014CrRes..51...75M. doi:10.1016/j.cretres.2014.05.017.
- ^ 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. Bibcode:2019NatSR...9.4940H. doi:10.1038/s41598-019-41280-4. PMC 6426928. PMID 30894614.
- ^ Medrano-Aguado, E.; Parrilla-Bel, J.; Gasca, J.M.; Alonso, A.; Canudo, J.I. (April 2023). "Ornithopod diversity in the Lower Cretaceous of Spain: New styracosternan remains from the Barremian of the Maestrazgo Basin (Teruel province, Spain)". Cretaceous Research. 144: 105458. Bibcode:2023CrRes.14405458M. doi:10.1016/j.cretres.2022.105458.