''Perijasaurus'' (meaning "Perija lizard") is a genus of basal eusauropod sauropod dinosaur from the " Girón-type redbeds" of the

La Quinta Formation The La Quinta Formation is a Jurassic geologic formation which crops out in the Cordillera de Mérida and Serranía del Perijá of western Venezuela and northeastern Colombia. The formation is also present in the subsurface of the Cesar-Rancher ...

Cesar Department Caesar Department ( es, Departamento del Cesar, links=no) or simply Caesar () is a department of Colombia located in the north of the country in the Caribbean region, bordering to the north with the Department of La Guajira, to the west with th ...

, north-eastern

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...

. The type species is ''Perijasaurus lapaz''. It lived during the Toarcian-Aalenian boundary around 175 million years ago early to middle

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

period.

Discovery and naming

The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

, UCMP 37689, is a broken dorsal vertebra, around tall and centimeters long. It was discovered on 27 March 1943 at the western flank of the

Serranía del Perijá The Serranía del Perijá, Cordillera de Perijá or Sierra de Perijá is a mountain range, an extension of the eastern Andean branch ( Cordillera Oriental), in northern South America, between Colombia and Venezuela Venezuela (; ), offici ...

mountain range by the Tropical Oil Company and was sent to the fossil collection at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant u ...

. Starting in 1955, UCMP 37689 had been mentioned in the literature with no consensus developing over its affinities. Eventually, the original site was rediscovered and the bone was prepared, allowing it to be named as a new genus and species, ''Perijasaurus lapaz'', in 2022. The generic name, "''Perijasaurus''", honors the mountain range where the fossil was found. The specific name, "''lapaz''", honors the town of

La Paz, Cesar Los Robles La Paz () or simply La Paz is a municipality and a town in the Department of Cesar, Colombia. The town is close to the Capital city of the Department of Cesar; Valledupar. The municipality of La Paz borders to the north with La Guajira ...

, near where the discovery was made, as well as the

peace agreement A peace treaty is an agreement between two or more hostile parties, usually countries or governments, which formally ends a state of war between the parties. It is different from an armistice, which is an agreement to stop hostilities; a surren ...

that allowed the described to perform fieldwork in the area ("la paz" in Spanish means "the peace").

Classification

Rincón ''et al.'' (2022) found ''Perijasaurus'' to be a basal eusauropod. The results of their phylogenetic analyses are shown in the cladogram below:

Paleoenvironment

''Perijasaurus'' hails from the La Quinta Formation of northern South America, in what is now

and

Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th ...

, making it the northernmost sauropod from

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

ever recorded as well as the first dinosaur found in the Colombian part of the La Quinta Formation. The La Quinta environment is interpreted as a tropical lowland forest. Its location and time suggests eusauropods reached a broad distribution before the breakup of Pangaea and the

Toarcian The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 182.7 Ma (million years ago) and 174.1 Ma. It follows the Pliensbachian and is followed by the Aalenian. The Toarcian ...

faunal turnover. Other dinosaurs from this formation include the stem-averostran theropod ''

Tachiraptor ''Tachiraptor'' ("thief of Táchira") is a genus of carnivorous Theropoda, theropod dinosaurs found in the early Jurassic period La Quinta Formation of Venezuela. It includes one species, ''Tachiraptor admirabilis'', described from a fossilized ...

'' and the ornithischian '' Laquintasaura'', both from Venezuela.

References

Eusauropoda Toarcian life Aalenian life Early Jurassic dinosaurs of South America Fossils of Colombia Jurassic Colombia Fossil taxa described in 2022 {{Sauropodomorph-stub