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 stage of the Early Cretaceous. Las Hoyas is a Konservat-Lagerstätte within the formation, located near the city of Cuenca, Spain. The site is mostly known for its exquisitely preserved dinosaurs, especially enantiornithines.
|La Huérguina Formation|
Stratigraphic range: Late Barremian
|Underlies||Contreras Formation or Unconformity with the Utrillas Group|
|Thickness||60 - 100 m|
|Extent||Province of Cuenca|
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.
Las Hoyas was an inland lacustrine environment which presents an important aquatic and terrestrial flora (with many specimens of Charophytes, Montsechia, Weischelia or Frenelopsis) and diverse fauna, with specimens of at least five or six Phyla: Arthropods, Molluscs, Chordata and many vermiform soft bodied animals which might be Nemertines or Annelids.
Among vertebrates the most abundant and diverse group are fish. 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).
Dinosaurs 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 are enantiornithes, 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 os quilled sternum. Eoalulavis hoyasi shows the first report of an alula or "bastard wing", which means it had a flight manoeuvrability analogous to that of modern birds.
Las Hoyas Formation has been studied for more than two decades by researchers from the Universidad Autónoma de Madrid, the Universidad Complutense de Madrid and the National University of Distance Education, in collaboration with the Museo de las Ciencias de Castilla-La Mancha, which is responsible for the fossil record from the area.
Uncertain or tentative taxa are in small text;
|Turtles reported from the La Huérguina Formation|
|Hoyasemys ||H. jimenezi||Las Hoyas|
|Squamates reported from the La Huérguina Formation|
|Becklesius||Indeterminate, B. cataphractus||Uña|
|Hoyalacerta||H. sanzi||Las Hoyas|
|Jucaraseps||J. grandipes||Las Hoyas|
|Meyasaurus||M. diazromerali||Las Hoyas|
|Scandensia||S. ciervensis||Las Hoyas|
|Mammals reported from the La Huérguina Formation|
Exceptionally complete specimen, preserving soft tissues such as pelage, ears and internal organs.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1994.2010 in archosaur paleontology
The year 2010 in Archosaur paleontology was eventful. Archosaurs include the only living dinosaur group — birds — and the reptile crocodilians, plus all extinct dinosaurs, extinct crocodilian relatives, and pterosaurs. Archosaur palaeontology is the scientific study of those animals, especially as they existed before the Holocene Epoch began about 11,700 years ago. The year 2010 in paleontology included various significant developments regarding archosaurs.
This article records new taxa of fossil archosaurs of every kind that have been described during the year 2010, as well as other significant discoveries and events related to paleontology of archosaurs that occurred in the year 2010.2012 in archosaur paleontology
The year 2012 in Archosaur paleontology was eventful. Archosaurs include the only living dinosaur group — birds — and the reptile crocodilians, plus all extinct dinosaurs, extinct crocodilian relatives, and pterosaurs. Archosaur palaeontology is the scientific study of those animals, especially as they existed before the Holocene Epoch began about 11,700 years ago. The year 2012 in paleontology included various significant developments regarding archosaurs.
This article records new taxa of fossil archosaurs of every kind that have been described during the year 2012, as well as other significant discoveries and events related to paleontology of archosaurs that occurred in the year 2012.2012 in paleontology
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 2012.
Note: In 2012 International Code of Zoological Nomenclature was amended, with new regulations allowing the publication of new names and nomenclatural acts in zoology after 2011 in works "produced in an edition containing simultaneously obtainable copies by a method that assures (...) widely accessible electronic copies with fixed content and layout", provided that the work is registered in ZooBank before it is published, the work itself states the date of publication with evidence that registration has occurred, and the ZooBank registration states both the name of an electronic archive intended to preserve the work and the ISSN or ISBN associated with the work. New scientific names appearing in electronic works are not required to be registered in ZooBank, only the works themselves are. Works containing descriptions of some of the taxa listed below weren't printed on paper in 2012; however, the taxa that were described in works which were registered in ZooBank in 2012 are listed as valid.2019 in paleobotany
This article records new taxa of fossil plants that are scheduled to be described during the year 2019, as well as other significant discoveries and events related to paleobotany that are scheduled to occur in the year 2019.Eoalulavis
Eoalulavis (from the Ancient Greek: Éōs, "dawn"; alula, "bastard wing"; avis, "bird") is a monotypic genus of enantiornithean bird that lived during the Barremian, in the Lower Cretaceous around 125 million years ago. The only known species is Eoalulavis hoyasi.Hoyasemys
Hoyasemys (meaning "turtle of Las Hoyas") is an extinct genus of basal eucryptodiran freshwater turtle from Lower Cretaceous (upper Barremian stage) deposits of Cuenca Province, Spain. It is known from the holotype MCCM-LH 84, a nearly complete and articulated skeleton including the skull. It was found in the 1980s from the Las Hoyas site of the Calizas de La Huérguina Formation, near La Cierva township, Spain. It was first named by Adán Pérez-García, Marcelo S. de la Fuente and Francisco Ortega in 2011 and the type species is Hoyasemys jimenezi. The generic name is derived from the word Hoyas meaning "the basin" in Spanish, which refers to the Las Hoyas fossil site it was found in, and emys ("freshwater turtle" in Greek). The specific name honors Dr. Emiliano Jiménez Fuentes.Iberomesornis
Iberomesornis ("Spanish intermediate bird") is a monotypic genus of enantiornithine bird of the Cretaceous of Spain.List of fossil sites
This list of fossil sites is a worldwide list of localities known well for the presence of fossils. Some entries in this list are notable for a single, unique find, while others are notable for the large number of fossils found there. Many of the entries in this list are considered Lagerstätten (sedimentary deposits that exhibits extraordinary fossils with exceptional preservation—sometimes including preserved soft issues). Lagerstätten are indicated by a note () in the noteworthiness column.
Fossils may be found either associated with a geological formation or at a single geographic site. Geological formations consist of rock that was deposited during a specific period of time. They usually extend for large areas, and sometimes there are different important sites in which the same formation is exposed. Such sites may have separate entries if they are considered to be more notable than the formation as a whole. In contrast, extensive formations associated with large areas may be equivalently represented at many locations. Such formations may be listed either without a site, with a site or sites that represents the type locality, or with multiple sites of note. When a type locality is listed as the site for a formation with many good outcrops, the site is flagged with a note (). When a particular site of note is listed for an extensive fossil-bearing formation, but that site is somehow atypical, it is also flagged with a note ().
Many formations are for all practical purposes only studied at a single site, and may not even be named. For example, sites associated with hominin, particularly caves, are frequently not identified with a named geologic formation. Therefore, some sites are listed without an associated formation.List of stratigraphic units with dinosaur body fossils
This is a list of stratigraphic units from which dinosaur body fossils have been recovered. Although Dinosauria is a clade which includes modern birds, this article covers only Mesozoic stratigraphic units. Units listed are all either formation rank or higher (e.g. group).Pelecanimimus
Pelecanimimus (meaning "pelican mimic") is a genus of basal ("primitive") ornithomimosaurian theropod dinosaur from the Early Cretaceous of Spain. It is notable for possessing more teeth than any other member of the Ornithomimosauria (or any other theropod), most of which were toothless.