The La Huérguina Formation (also known as the Calizas de La Huérguina Formation, La Huérguina Limestone Formation or as the Una Formation) is a geological
formation in Spain whose strata date back to the
Barremian
The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 125.77 Ma (million years ago) and 121.4 ± 1.0 Ma (Historically, this stage was placed at 129.4 million to approximately 125 million years ago) It is a ...
stage of the
Early Cretaceous
The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...
.
[Martínez et al., 2017] Las Hoyas is a Konservat-
Lagerstätte
A Fossil-Lagerstätte (, from ''Lager'' 'storage, lair' '' Stätte'' 'place'; plural ''Lagerstätten'') is a sedimentary deposit that preserves an exceptionally high amount of palaeontological information. ''Konzentrat-Lagerstätten'' preserv ...
within the formation, located near the city of
Cuenca, Spain
Cuenca () is a city and municipalities in Spain, municipality of Spain located in the Autonomous communities of Spain, autonomous community of Castilla–La Mancha. It is the capital of the Province of Cuenca.
Etymology
Its name may derive fro ...
. The site is mostly known for its exquisitely preserved
dinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...
s, especially
enantiornithines.
[Weishampel et al., 2004, pp.556-563] The lithology of the formation mostly consists of
lacustrine limestone
Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...
deposited in a freshwater wetland environment.
Las Hoyas
Taphonomy
As a
Konservat-Lagerstätten, the preservation is exceptional. This may be a result of three factors: Microbial mats, Obruption and Stagnation.
Microbial mats may be responsible for the preservation of soft tissue in many fossils from Las Hoyas, like ''
Pelecanimimus''
' crest. The iron carbonate depositions, a result from bacterial metabolism which covered the dinosaur's crest enhanced the preservation of those soft tissues. Evidence of these mats comes from the studies on microfacies and the fossils themselves.
Obruption is notable in the formation, due to the presence of highly articulated specimens. From actuotaphonomy studies on several different organisms it can be estimated that the burial of most entities was quick. ''
Concornis'' may have been buried in less than 15 days, after a period of sub-areal exposition.
Paleoenvironment
Las Hoyas was an inland lacustrine environment which presents an important aquatic and terrestrial
flora
Flora (: floras or florae) is all the plant life present in a particular region or time, generally the naturally occurring (indigenous (ecology), indigenous) native plant, native plants. The corresponding term for animals is ''fauna'', and for f ...
(with many specimens of
Charophytes
Charophyta () is a Paraphyly, paraphyletic group of freshwater green algae, called charophytes (), sometimes treated as a Division (taxonomy), division, yet also as a Division (taxonomy), superdivision. The terrestrial plants, the Embryophyta em ...
, ''
Montsechia'', ''
Weischelia'' or ''
Frenelopsis'') and diverse
fauna
Fauna (: faunae or faunas) is all of the animal life present in a particular region or time. The corresponding terms for plants and fungi are ''flora'' and '' funga'', respectively. Flora, fauna, funga and other forms of life are collectively ...
, with specimens of at least five or six
Phyla
Phyla, the plural of ''phylum'', may refer to:
* Phylum, a biological taxon between Kingdom and Class
* by analogy, in linguistics, a large division of possibly related languages, or a major language family which is not subordinate to another
Phy ...
:
arthropods
Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...
,
molluscs
Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...
,
Chordata
A chordate ( ) is a bilaterian animal belonging to the phylum Chordata ( ). All chordates possess, at some point during their larval or adult stages, five distinctive physical characteristics (Apomorphy and synapomorphy, synapomorphies) th ...
and many
vermiform
Vermes (" vermin/vermes") is an obsolete taxon used by Carl Linnaeus and Jean-Baptiste Lamarck for non-arthropod invertebrate animals.
Linnaeus
In Linnaeus's ''Systema Naturae'', the Vermes had the rank of class, occupying the 6th (and last) ...
soft bodied animals which might be
Nemertines or
annelids
The annelids (), also known as the segmented worms, are animals that comprise the phylum Annelida (; ). The phylum contains over 22,000 extant species, including ragworms, earthworms, and leeches. The species exist in and have adapted to vario ...
.
Among
vertebrates
Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain.
The vertebrates make up the subphylum Vertebra ...
the most abundant and diverse group are
fish
A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...
. The presence of mostly articulated skeletons, exceptional preservation of tissue and lack of any other signs of transportation may indicate that these are demic and autochthonous entities (meaning that they lived and died in the same place where they fossilized).
Crocodylomorphs are the most abundant
amniotes
Amniotes are tetrapod vertebrate animals belonging to the clade Amniota, a large group that comprises the vast majority of living terrestrial and semiaquatic vertebrates. Amniotes evolved from amphibious stem tetrapod ancestors during the ...
from Las Hoyas.
Dinosaurs
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...
from Las Hoyas (avian and non avian) are unique in many ways. The first
ornithomimosaur dinosaur described in Europe, ''
Pelecanimimus polyodon'', shows some characters previously unknown in these dinosaurs which enhanced the knowledge on the evolution of the group, such as a high number of teeth. ''
Concavenator corcovatus'' presents two unique features: very tall neural spines on the vertebrae near the hip, which look like a hump, and a structure on its forearm, which if homologous to
quill knobs would push back the origin of feathers earlier in theropod evolution.
Las Hoyas
birds
Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...
are
enantiornithes
The Enantiornithes, also known as enantiornithines or enantiornitheans in literature, are a group of extinct Avialae, avialans ("birds" in the broad sense), the most abundant and diverse group known from the Mesozoic era. Almost all retained teet ...
, the most diverse Cretaceous bird clade, which became extinct at the end of the period. ''
Iberomesornis romerali'' shows both derived ("avian") and primitive ("dinosaurian") characters. Within the derived characters we can underline the presence of a pygostile, although it is still very large compared to that of modern
neornithines and the presence of a quilled sternum. ''
Eoalulavis hoyasi
''Eoalulavis'' (from the Ancient Greek: Eos, ''Éōs'', "dawn"; ''alula'', alula, "bastard wing"; ''avis'', "bird") is a monotypic taxon, monotypic genus of Enantiornithines, enantiornithean bird that lived during the Barremian, in the Lower Cret ...
'' shows the first report of an
alula
The alula , or bastard wing, (plural ''alulae'') is a small projection on the anterior edge of the wing of modern birds and a few non-avian dinosaurs. The word is Latin and means "winglet"; it is the diminutive of ''ala'', meaning "wing". The a ...
or "bastard wing", which means it had a flight manoeuvrability analogous to that of modern birds.
Research
The Las Hoyas site has been studied for more than two decades by researchers from the
Universidad Autónoma de Madrid, the
Universidad Complutense de Madrid
The Complutense University of Madrid (, UCM; ) is a public research university located in Madrid. Founded in Alcalá in 1293 (before relocating to Madrid in 1836), it is one of the oldest operating universities in the world, and one of Spain's ...
and the
National University of Distance Education
The National Distance Education University (, UNED) is a distance learning and research university founded in 1972 and is the only university run by the government of Spain. The headquarters is located in Madrid, with campuses in all Spanish aut ...
, in collaboration with the
Museo de las Ciencias de Castilla-La Mancha, which is responsible for the fossil record from the area.
Fossil content
Crustaceans
Chondrichthyes
Osteichthyes
Amphibians
Turtles
Squamates
Mammals
Crocodyliformes
Ornithodirans
Correlation
See also
*
List of dinosaur-bearing rock formations
This list of dinosaur-bearing rock formations is a list of geologic formations in which dinosaur fossils have been documented.
* List of stratigraphic units with dinosaur body fossils
* List of stratigraphic units with dinosaur trace fossils
** ...
*
Paja Formation
The Paja Formation (, K1p, Kip, Kimp, b3b6p) is an Early Cretaceous formation (geology), geologic formation of central Colombia. The formation extends across the northern part of the Altiplano Cundiboyacense, the Colombian emeralds#Western belt, W ...
, contemporaneous Lagerstätte of Colombia
*
Yixian Formation
The Yixian Formation (; formerly Romanization of Chinese, transcribed as Yihsien Formation or Yixiang Formation) is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans the Barremian stage of the Early Cretaceous. I ...
, contemporaneous Lagerstätte of China
References
Bibliography
*
*
*
* Thomas Martin, Jesús Marugán-Lobón, Romain Vullo, Hugo Martín-Abad, Zhe-Xi Luo & Angela D. Buscalioni (2015). A Cretaceous eutriconodont and integument evolution in early mammals. Nature 526, 380–384. doi:10.1038/nature14905
*
Ortega, F., Escaso, F. & Sanz, J. L. (2010): A bizarre, humped Carcharodontosauria (Theropoda) from the Lower Cretaceous of Spain ''
Nature
Nature is an inherent character or constitution, particularly of the Ecosphere (planetary), ecosphere or the universe as a whole. In this general sense nature refers to the Scientific law, laws, elements and phenomenon, phenomena of the physic ...
'' 467: 203–206
HTML abstract*
*
Sanz, José L.; Chiappe, Luis M.; Pérez Moreno, Bernardino P.; Buscalioni, Ángela D.; Moratalla, José J.; Ortega, Francisco & Poyato Ariza, Francisco J. (1996): An Early Cretaceous bird from Spain and its implications for the evolution of avian flight. ''
Nature
Nature is an inherent character or constitution, particularly of the Ecosphere (planetary), ecosphere or the universe as a whole. In this general sense nature refers to the Scientific law, laws, elements and phenomenon, phenomena of the physic ...
'' 382(6590): 442–445.
(HTML abstract)
* Pérez Moreno, B. P., Sanz, J. L., Buscalioni, A. D., Moratalla, J. J., Ortega, F., and Raskin-Gutman, D. (1994). "A unique multitoothed ornithomimosaur from the Lower Cretaceous of Spain." Nature, 30: 363–367.
* Sanz, J. L. & Bonaparte, José F. (1992): A New Order of Birds (Class Aves) from the Lower Cretaceous of Spain. ''In'': Jonathan J. Becker (ed.): Papers in Avian Paleontology Honoring Pierce Brodkorb. ''Natural History Museum of Los Angeles County Contributions in Science'' 36: 38–49.
*
Sanz, J. L. & Buscalioni, A.D. (1992): A new bird from the Early Cretaceous of Las Hoyas, Spain, and the early radiation of birds. ''
Palaeontology
Paleontology, also spelled as palaeontology or palæontology, is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure geo ...
'' 35(4): 829–845.
External links
Las Hoyas site website
{{DEFAULTSORT:Calizas De La Huergina Formation
Geologic formations of Spain
Lower Cretaceous Series of Europe
Cretaceous Spain
Limestone formations
Marl formations
Lacustrine deposits
Cretaceous paleontological sites of Europe
Paleontology in Spain
Formations