The Rosario Group is a

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

geologic group In geology, a group is a lithostratigraphic unit consisting of a series of related formations that have been classified together to form a group. Formations are the fundamental unit of stratigraphy. Groups may sometimes be combined into superg ...

in southwestern

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

(United States) and northwestern

Baja California Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...

(Mexico). In older literature it was named Rosario Formation. The Cretaceous aged formations of the Rosario Group include the

Point Loma Formation The Point Loma Formation is a sedimentary geological formation in Southern California. The strata date back to the Late Cretaceous epochs of the Cretaceous period, during the Mesozoic Era. The formation is named after the Point Loma peninsula ...

, Cabrillo Formation and

Lusardi Formation Lusardi is a surname. Notable people with the surname include: * Andrea Lussardi (born 1992), Italian footballer * Greg Lusardi (born 1953), American football player and coach * Hugo Lusardi (1982–2022), Paraguayan professional footballer *Linda ...

, in ascending order. The sedimentary structures of the Rosario Group apparently were formed in a nearshore shelf environment, probably a local embayment.

Fossils

Some incomplete dinosaur

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 ...

have been discovered in the Point Loma Formation dating back to the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

period Period may refer to: Common uses * Period (punctuation) * Era, a length or span of time *Menstruation, commonly referred to as a "period" Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (o ...

of the

Mesozoic Era The Mesozoic Era is the era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Periods. It is characterized by the dominance of archosaurian reptiles such as the dinosaurs, and of gymnosperms s ...

Fossils

See also

References

Further reading