The Agua Nueva Formation is a

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

. It preserves

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...

dating back to the upper part of the

Cenomanian The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the s ...

stage of the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

. It consists "predominantly of alternating fossiliferous, organic matter-rich, laminated, dark gray limestone and non-laminated, organic matter-poor limestone in decimeter-thick beds (10 to 30 cm) with occasional centimetric beds (5 cm) of brown shale that show no apparent internal structures." The formation is noted for its qualities as a Konservat-Lagerstätte, with notable finds including the plesiosaur ''

Mauriciosaurus ''Mauriciosaurus'' (meaning "Mauricio ernández Garza'sreptile") is a genus of polycotylid plesiosaur from the Late Cretaceous of Mexico. It contains a single species, ''M. fernandezi'' (also named after Fernández Garza), described in 2017 by E ...

'' and shark ''

Aquilolamna ''Aquilolamna'' is an extinct genus of shark-like elasmobranch from the Late Cretaceous (Turonian)-aged Agua Nueva Formation of Mexico. It is currently known to contain only one species, ''A. milarcae'', also known as the eagle shark, and it is ...

.''

References

External links

* Geologic formations of Mexico Cretaceous Mexico {{Cretaceous-stub

See also

References

External links