{{Short description|Geological formation in Uruguay}} {{Infobox rockunit | name = Asencio Formation | image = | caption = | type = Geological formation | period = Campanian-Maastrichtian | age = Campanian-Maastrichtian<br>~{{fossil range|83.6|66.0}} | prilithology = Sandstone | otherlithology = | namedfor = Cry of Asencio | namedby = | region = Colonia, Río Negro, Soriano, Tacuarembó | country = Uruguay | coordinates = {{coord|33.0|S|57.2|W|display=inline,title}} | paleocoordinates = {{coord|36.6|S|41.6|W|display=inline}} | unitof = | subunits = Del Palacio Member | underlies = Queguay & Fray Bentos Formations | overlies = Mercedes Formation | thickness = | extent = Paraná Basin | area = | map = {{Location map+ | Uruguay | relief = 1 | width = 250 | float = center | places = {{Location map~ | Uruguay | lat_deg = -33.0 | lon_deg = -57.2 | mark = Lightgreen pog.svg | marksize = 12 }} }} | map_caption = }} The '''Asencio Formation''' is a geological formation in the Paraná Basin of southwestern Uruguay whose strata date back to the Late Cretaceous (Campanian-Maastrichtian). Dinosaur remains are among the fossils that have been recovered from the formation.<ref name="cretaceousdistribution">Weishampel et al., 2004, pp. 600-604</ref>
== Vertebrate paleofauna == * ''Neuquensaurus australis''<ref>[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=64315 Neuquensaurus australis] at Fossilworks.org</ref> * ''Laplatasaurus araukanicus''<ref>[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=64322 Laplatasaurus araukanicus] at Fossilworks.org</ref> * ''Antarctosaurus wichmannianus''<ref name="comunic1972")>{{cite journal |url=https://www.mna.gub.uy/innovaportal/file/10917/1/cp3.pdf |title=Lista de los vertebrados fósiles de Uruguay, I. Chondrichthyes, Osteichthyes, Reptilia, Aves |journal=Comunicaciones Paleontológicas del Museo de Historia Natural de Montevideo |page=30 |volume=I |issue=3 |year=1972 |last=Mones |first=Álvaro |authorlink=Álvaro Mones |access-date=20 December 2025 }}</ref>
=== Fossil eggs === * ''Sphaerovum erbeni''<ref name="Mones 1980">Mones, A. (1980) "Nuevos elementos de la paleoherpetofauna del Uruguay (Crocodilia y Dinosauria)." ''Actas II Congreso Argentino de Paleontologia y Bioestratigrafia y I Congreso Latinoamericano, Buenos Aires'' 1:265-277 (in Spanish)</ref> * ''Tacuarembovum oblongum''<ref name="Mones 1980"/>
== Trace fossils == * ''Teisseirei''<ref>{{cite web |url=https://www.colibri.udelar.edu.uy/jspui/bitstream/20.500.12008/29508/1/uy24-19957.pdf |title=Trabajo final de licenciatura en geología: "Mapa geológico de la región al sur de la ciudad de Mercedes y caracterización litológica de la formación Asencio" |website=UdelaR, Facultad de Ciencias |last=Novo Buess |first=Anaclara |year=2020 |language=es |access-date=14 December 2025 }}</ref> * ''Elipsoideichnus meyeri''<ref>{{Cite journal |url=https://turia.uv.es/index.php/sjpalaeontology/article/view/17485/15687 |title=Elipsoideichnus meyeri Roselli 1987 revisited: A helicoidal fossil bee nest from the Paleogene of Uruguay |access-date=15 December 2025 |journal=Spanish Journal of Palaeontology |last=Verde |first=Mariano |last2=Genise |first2=Jorge F. |authorlink=Jorge Fernando Genise |year=2014 |volume=29 |issue=1 |pages=25-32 }}</ref> * ''Corimbatichnus''<ref>{{cite journal |url=https://www.tandfonline.com/doi/abs/10.1080/10420940009380150 |title=Corimbatichnus fernandezi: A cluster of fossil bee cells from the late cretaceous‐early tertiary of Uruguay |access-date=17 December 2025 |journal=Ichnos |volume=7 |issue=2 |pages=115-125 |doi=10.1080/10420940009380150 |hdl=11336/70104 |hdl-access=free }}</ref>
== See also == * List of dinosaur-bearing rock formations * List of fossiliferous stratigraphic units in Uruguay * Adamantina Formation * Allen Formation * Marília Formation
== References == {{Reflist}}
=== Bibliography === * {{citation |last1=Weishampel |first1=David B. |author2-link=Peter Dodson |last2=Dodson |first2=Peter |author3-link=Halszka Osmólska |last3=Osmólska |first3=Halszka |year=2004 |title=The Dinosauria, 2nd edition |url=https://books.google.com/books?id=vtZFDb_iw40C |publisher=Berkeley: University of California Press |pages=1–880 |accessdate=2019-02-21 |isbn=0-520-24209-2 |author1-link=David B. Weishampel }}
== Further reading == * F. v. Huene. 1929. Terrestrische Oberkreide in Uruguay [The terrestrial Upper Cretaceous in Uruguay]. Centralblatt für Mineralogie, Geologie und Paläontologie Abteilung B 1929:107-112
{{Stratigraphic formations of Uruguay}} {{Authority control}}
Category:Asencio Formation Category:Geologic formations of Uruguay Category:Upper Cretaceous Series of South America Category:Cretaceous Uruguay Category:Campanian Stage Category:Maastrichtian Stage of South America Category:Sandstone formations Category:Ooliferous formations Category:Paleontology in Uruguay Formations Category:Geography of Colonia Department Category:Geography of Río Negro Department Category:Geography of Soriano Department Category:Geography of Tacuarembó Department