An aptychus is a type of marine fossil. It is a hard anatomical structure, a sort of curved shelly plate, now understood to be part of the body of an ammonite. Paired aptychi have, on rare occasions, been found at or within the aperture of ammonite shells. The aptychus was usually composed of calcite, whereas the ammonite shell was aragonite.
Dakosaurus is an extinct genus of crocodylomorph within the family Metriorhynchidae that lived during the Late Jurassic and Early Cretaceous. It was large, with teeth that were serrated and compressed lateromedially. The genus was established by Friedrich August von Quenstedt in 1856 for an isolated tooth named Geosaurus maximus by Theodor Plieninger in 1846. Dakosaurus was a carnivore that spent much, if not all, its life out at sea. The extent of its adaptation to a marine lifestyle means that it is most likely that it mated at sea, but since no eggs or nests have been discovered that have been referred to Dakosaurus, whether it gave birth to live young at sea like dolphins and ichthyosaurs or came ashore like turtles is not known. The name Dakosaurus means "biter lizard", and is derived from the Greek dakos ("biter") and σαῦρος -sauros ("lizard").
Sistema Ox Bel Ha is a cave system in Quintana Roo, Mexico. It is the longest explored underwater cave in the world and ranks second including dry caves. As of January 2023 the surveyed length is 435.8 kilometers (270.8 mi) of underwater passages. There are more than 150 cenotes in the system.
Geosaurus is an extinct genus of marine crocodyliform within the family Metriorhynchidae, that lived during the Late Jurassic and the Early Cretaceous. Geosaurus was a carnivore that spent much, if not all, its life out at sea. No Geosaurus eggs or nests have been discovered, so little is known of the reptile's lifecycle, unlike other large marine reptiles of the Mesozoic, such as plesiosaurs or ichthyosaurs which are known to give birth to live young out at sea. Where Geosaurus mated, whether on land or at sea, is currently unknown. The name Geosaurus means "Mother of Giants lizard", and is derived from the Greek Ge- and σαῦρος -sauros ("lizard"). The name Geosaurus was established by the French naturalist Georges Cuvier in 1824.
Muzquizopteryx is a genus of nyctosaurid pterodactyloid pterosaur from the Late Cretaceous period of what is now Coahuila, Mexico.
The Cerro del Pueblo Formation is a geological formation in Coahuila, Mexico whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation. The formation is believed to correlate with the Baculites reesidesi and Baculites jenseni ammonite zones, which dates it to 73.63-72.74 Ma.
Amphekepubis is a dubious genus of mosasaur from the Late Cretaceous of Mexico. Their remains correspond to the holotype specimen UM VP 509, a partial skeleton preserved in three dimensions, comprising the pelvic area, hind limb bones and nine caudal vertebrae, found in the east of Monterrey, in the state of Nuevo Leon, which come from marine sediments (claystones) apparently from the San Felipe Formation, which corresponds to the boundary between the ages of Coniacian and Santonian in the early Late Cretaceous. Amphekepubis is classified within the Mosasaurinae subfamily of mosasaurs.
The "monster of Aramberri" is the name that was given to the fossil remains of a huge marine reptile, a giant carnivore belonging to the Pliosauroidea clade that was found in sediments of the La Caja Formation in Aramberri, Nuevo León, Mexico by a student of the Facultad de Ciencias de la Tierra of the Universidad Autónoma de Nuevo León while conducting geological mapping in 1985.
This list, 2013 in molluscan paleontology, is a list of new taxa of ammonites and other fossil cephalopods, as well as fossil gastropods, bivalves and other molluscs that have been described during the year 2013.
The Malone Formation is a geologic formation in Texas. It preserves fossils dating back to the Jurassic period.
The La Casita Formation is a geologic formation in Mexico. It preserves fossils dating back to the Kimmeridgian to lowermost Berriasian. It is laterally equivalent to the La Caja Formation and the Pimienta Formation. The ichthyosaurs Jabalisaurus and Acuetzpalin are known from the formation, as well as the metriorhynchid Dakosaurus and indeterminate pliosaurs.
The Pimienta Formation is a geologic formation in Mexico. It preserves fossils dating back to the Tithonian-Berriasian. The formation is considered laterally equivalent to the La Casita Formation. The Metriorhynchid Cricosaurus vignaudi is known from the formation.
The Artemisa Formation is a geologic formation in western Cuba. It preserves mainly ammonite fossils dating back to the Late Oxfordian to Tithonian period. The formation is divided into two members; La Zarza and Sumidero Members. Most of the formation was deposited in deeper marine conditions.
Zapata Formation is a sedimentary formation of Lower Cretaceous age in the Magallanes or Austral Basin of Argentina and Chile. Much of the formation is folded and faulted as consequence of the Andean orogeny. In outcrops of the Zapata Formation near Torres del Paine, the ichthyosaur genus Myobradypterygius has been found.
Laevapetchyus is a genus of ammonites.
Xibalbaonyx is an extinct genus of megalonychid ground sloth known from the Late Pleistocene of Mexico. Three species are known: X. oviceps and X. exiniferis from the Yucatan peninsula and X. microcaninus from Jalisco. The genus is named after Xibalba, the underworld in Maya mythology.
Acuetzpalin is an extinct genus of platypterygiine ophthalmosaurid ichthyosaur found in the Kimmeridgian La Casita Formation in Mexico. It is known from a partial skeleton, of which the skull is surprisingly well preserved. Its length is estimated to have been more than 3.1 metres (10 ft) long, considering the missing parts of the holotype. It was the first ichthyosaur described in 2020 and the first new ichthyosaur genus described since 2017.
Parrassaurus is an ophthalmosaurid ichthyosaur from the late Jurassic La Caja Formation of Mexico found in 2021. Parrassaurus includes one species, Parrassaurus yacahuitztli. The type specimen was around 5 metres (16 ft) long.
Jabalisaurus is an ophthalmosaurid ichthyosaur from the Late Jurassic La Caja Formation of Mexico. It contains a single species, Jabalisaurus meztli.
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