El Doctor Formation | |
---|---|
Stratigraphic range: Albian-Cenomanian ~ | |
Type | Formation |
Sub-units | La Negra Member |
Lithology | |
Primary | Lime mudstone |
Location | |
Coordinates | 20°48′N99°18′W / 20.8°N 99.3°W |
Approximate paleocoordinates | 18°54′N64°30′W / 18.9°N 64.5°W |
Region | Hidalgo |
Country | Mexico |
The El Doctor Formation is a geologic formation in Mexico. It preserves fossils dating back to the Albian and Cenomanian stages of the Cretaceous period. [1] Ammonite fossils show that age of Late Albian is more likely. [2]
The light grey micritic limestone sequence with intercalated black chert lenses was deposited in an open marine basin with a hypersaline and/or poorly oxygenated bottom. [1]
The formation has provided the following fossils: [1] [3] [4] [5] [2]
Enchodus is an extinct genus of aulopiform ray-finned fish related to lancetfish and lizardfish. Species of Enchodus flourished during the Late Cretaceous, and there is some evidence that they may have survived to the Paleocene or Eocene; however, this may just represent reworked Cretaceous material.
Ichthyodectiformes is an extinct order of marine stem-teleost ray-finned fish. The order is named after the genus Ichthyodectes, established by Edward Drinker Cope in 1870. Ichthyodectiforms are usually considered to be some of the closest relatives of the teleost crown group.
Axelrodichthys is an extinct genus of mawsoniid coelacanth from the Cretaceous of Africa, North and South America, and Europe. Several species are known, the remains of which were discovered in the Lower Cretaceous (Aptian-Albian) of Brazil, North Africa, and possibly Mexico, as well as in the Upper Cretaceous of Morocco (Cenomanian), Madagascar and France. The Axelrodichthys of the Lower Cretaceous frequented both brackish and coastal marine waters while the most recent species lived exclusively in fresh waters. The French specimens are the last known fresh water coelacanths. Most of the species of this genus reached 1 metre to 2 metres in length. Axelrodichthys was named in 1986 by John G. Maisey in honor of the American ichthyologist Herbert R. Axelrod.
The Paw Paw Formation is a geological formation in Texas whose strata date back to the late Albian stage of the Early Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.
Anaethalion is an extinct genus of prehistoric marine and freshwater ray-finned fish related to modern tarpons and ladyfish. It is known from the Late Jurassic to the Early Cretaceous of Europe and northeasterrn Asia, roughly encompassing the Tethys Ocean.
The Mowry Shale is an Early Cretaceous geologic formation. The formation was named for Mowrie Creek, northwest of Buffalo in Johnson County, Wyoming.
Aegeridae is a family of fossil prawns, one of the earliest Mesozoic shrimp families. It contains the genera Aeger, Acanthochirana, Anisaeger and Distaeger. The main diagnostic character of Aegeridae is the presence of numerous spines or thin setae on the third maxilliped.
The Tlayúa Formation is an Early Cretaceous geological formation near Tepexi de Rodríguez, Puebla.
Callipurbeckia is an extinct genus of marine semionotiform ray-finned fish from the Late Jurassic and Early Cretaceous periods. Fossils have been found in Germany, Tanzania, and England.
This list of fossil arthropods described in 2014 is a list of new taxa of trilobites, fossil insects, crustaceans, arachnids and other fossil arthropods of every kind that have been described during the year 2014. The list only includes taxa at the level of genus or species.
This list of fossil fishes described in 2013 is a list of new taxa of placoderms, fossil cartilaginous fishes and bony fishess of every kind that have been described during the year 2013. The list only includes taxa at the level of genus or species.
The Sannine Formation, also called the Sannine Limestone, is a Cretaceous geologic formation in Lebanon. It is a Konservat-Lagerstätte that contains a high diversity of well-preserved fish, reptiles, and invertebrates from the Tethys Ocean within its three main localities: Haqel, Hjoula, and Nammoura.
The Sierra Madre Formation is a geologic formation in Chiapas state, southern Mexico. It consists of marine dolomites and limestones. The formation dates to the Middle Cretaceous, spanning from the Aptian of the Early to the Cenomanian of the Late Cretaceous.
Mauriciosaurus is a genus of polycotylid plesiosaur from the Late Cretaceous of Mexico. It contains a single species, M. fernandezi, described in 2017 by Eberhard Frey and colleagues from a single well-preserved juvenile specimen about 1.9 metres long. Morphologically, it is overall most similar to the polycotyline polycotylids Trinacromerum and Dolichorhynchops. However, several features separate Mauriciosaurus from all other polycotylids, warranting the naming of a new genus. These include the sophisticated pattern of ridges on the bottom of the parasphenoid bone on its palate; the narrow openings in the palate bordered by the pterygoid bones; the lack of perforations in the surface of the coracoid; and the highly unusual arrangement of gastralia, or belly ribs, which is only otherwise seen in the non-polycotylid Cryptoclidus.
Aeger libanensis is a species of fossil prawn belonging to the family Aegeridae. These prawns had very long pereiopods.
Goulmimichthys is an extinct genus of ray-finned fishes in the family Pachyrhizodontidae. The genus, first described by Cavin in 1995, is known from various Turonian age formations. The type species G. arambourgi from the Akrabou Formation in the El Rachidia Province of Morocco, and other fossils described are G. gasparini of the La Frontera Formation, Colombia, and G. roberti from the Agua Nueva Formation of Mexico.
Bachea is an extinct genus of ray-finned fish that lived during the Late Cretaceous in what is now central Colombia, South America. The type species is Bachea huilensis, described in 1997 by María Páramo from the Turonian of Huila, Colombia.
Enchodontidae is an extinct family of aulopiform ray-finned fish known from the mid-late Cretaceous. It contains two subfamilies with several genera, including the famous Enchodus, with great morphological disparity among members of the group.
The Enchodontoidei are an extinct superorder of aulopiform fish known from the Early Cretaceous to the Eocene. They were among the dominant predatory marine fish groups in the Late Cretaceous, achieving a worldwide distribution. They were an extremely diverse group, with some developing fusiform body plans whereas others evolved elongated body plans with long beaks, superficially similar to eels and needlefish. They could also grow to very large sizes, as seen with Cimolichthys and Stratodus, the latter of which is the largest aulopiform known. Their most famous member is the widespread, abundant, and long-lasting genus Enchodus.
Xeneichthys is an extinct genus of teleost fish from the Albian El Doctor Formation in Hidalgo, Mexico. The type and only species is X. yanesi is known from multiple specimens, representing the entire body.