Marasuchus
bipedal reptile and close relative of dinosaurs
Marasuchus (meaning "Mara crocodile") is an early genus of dinosauriform archosaur, one of the closest relatives of dinosaurs. It is sometimes regarded as a junior synonym of Lagosuchus (which would make Marasuchus an invalid later name for Lagosuchus fossils). Both names have been applied to small bipedal dinosauriform fossils from the same time and place: the Late Triassic (early Carnian stage) of what is now La Rioja Province, Argentina. If valid, Marasuchus contains a single species, Marasuchus lilloensis.
Marasuchus lilloensis was originally designated as Lagosuchus lilloensis in 1972. It was named for a few well-preserved dinosauriform fossils stored at PVL, a museum in San Miguel de Tucuman. L. lilloensis is the second named species of Lagosuchus, a contemporary archosaur described from a smaller and more fragmentary fossil the previous year. A 1994 study argued that the first species, Lagosuchus talampayensis, has insufficient fossil material to justify its continued use. In response, the same study gave the better-preserved PVL fossils a new genus: Marasuchus.
On the other hand, a 2019 study redescribed the original material of Lagosuchus and came to the opposite conclusion: that it was valid and not readily distinguishable from Marasuchus lilloensis.
The public source identifies “Marasuchus” as bipedal reptile and close relative of dinosaurs. This brief keeps that definition visible, then builds a research path around Marasuchus, bipedal and reptile.
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Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Aug 3, 2026. The linked authority identifier is Q133233. The first chronological checks are 1972, 1994 and 2019.
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This entry incorporates text from “Marasuchus” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.