Allen Formation

{{Infobox rockunit

| name = Allen Formation

| image = Fms Anacleto Allen Auca Mahuida 1.jpg

| caption = Outcrop of the Allen and Anacleto Formations at Auca Mahuida

| type = Geological formation

| age = Mid Campanian-Maastrichtian
~{{fossilrange|73|69}}

| period = Campanian

| prilithology = Mudstone, sandstone

| otherlithology = Limestone

| namedfor =

| namedby = Uliana & Dellapé

| year_ts = 1981

| region = Neuquén, Río Negro & La Pampa Provinces

| country = Argentina

| coordinates = {{coord|40.0|S|66.6|W|display=inline,title}}

| paleocoordinates = {{coord|42.8|S|52.2|W|display=inline}}

| unitof = Malargüe Group

| subunits =

| underlies = Jagüel Formation

| overlies = Anacleto Formation

| thickness = up to {{convert|70|m|ft|abbr=on}}

| extent = Neuquén Basin

| area =

| map = {{Location map+ | Argentina

| relief = 1

| width = 250

| float = center

| places =

{{Location map~ | Argentina

| lat_deg = -40.0

| lon_deg = -66.6

| mark = Lightgreen pog.svg

| marksize = 12

}}

| map_caption =

}}

The Allen Formation is a geological formation in Argentina whose strata date back to the Late Cretaceous (middle Campanian to early Maastrichtian.Salgado et al., 2007 Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, South America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 600-604. {{ISBN|0-520-24209-2}}. Indeterminate chelid remains and other vertebrates have also been discovered in this formation.

Description

File:Allen Formation Fauna.png

Uliana and Dellapé defined the formation's stratotype in 1981 in the eastern area of the Bajo de Añelo, where the relation between the base and top is clearly exposed. The deposits are mostly clastic, interbedded with banks of limestone and layers of anhydrite, which were defined as continental and shallow marine facies associated with semiarid conditions.Armas & Sánchez, 2015, p.101

The interpreted sedimentary paleoenvironments range from purely continental such as ephemeral lacustrine, aeolian and fluvial systems to coastal marine paleoenvironments with development of estuaries and tidal flats, followed by a lagoon sedimentary stage from marsh to sea with carbonate precipitation in an area protected from waves, ending with a retraction leading to the accumulation of evaporites.

Armas and Sánchez performed a detailed facies analysis of the formation in 2015, where the authors concluded the formation represents a hybrid coastal system

of tidal flats, dominated by Atlantic ingressions, with a large storm influence in some areas linked to aeolian systems.Armas & Sánchez, 2015, p.110

Fossil content

File:Quilmesaurus hunting Bonapartesaurus version 2.jpg of Dinosaurs discovered from Allen Formation]]

= Dinosaurs =

Dinosaur eggs are known from the formation.

== Ornithischians ==

; Ankylosaurs

class="wikitable" align="center"
Genus ! Species ! Location ! Stratigraphic position ! Material ! Notes ! Images
Ankylosauria{{Cite journal \|last1=Álvarez Nogueira \|first1=Rodrigo \|last2=Agnolín \|first2=Federico L. \|last3=Rozadilla \|first3=Sebastián \|last4=Aranciaga-Rolando \|first4=Mauro \|last5=Novas \|first5=Fernando E. \|date=2025-02-25 \|title=Ankylosaurian remains from a new Campanian–Maastrichtian locality in Northern Patagonia, Argentina \|journal=Alcheringa: An Australasian Journal of Palaeontology \|language=en \|pages=1–10 \|doi=10.1080/03115518.2025.2467462 \|issn=0311-5518}} \|Indeterminate \|Arriagada Farm \| \|Two teeth, five osteoderms, and a partial sacrum \|Fossil remains possibly belonging to a parankylosaur distinct from Patagopelta \|
Patagopelta \|P. cristata \| Salitral Moreno locality \|Lower \|Tooth, three posterior dorsal vertebrae, caudal vertebrae, two caudal centra, right femur, partial cervical half ring, and osteoderms. \| A parankylosaur{{Cite journal \|last1=Soto Acuña \|first1=Sergio \|last2=Vargas \|first2=Alexander O. \|last3=Kaluza \|first3=Jonatan \|date=2024 \|title=A new look at the first dinosaur discovered in Antarctica: reappraisal of Antarctopelta oliveroi (Ankylosauria: Parankylosauria) \|journal=Advances in Polar Science \|volume=35 \|issue=1 \|pages=78–107 \|doi=10.12429/j.advps.2023.0036 \|doi-access=free}} \| File:Patagopelta into the water.png

class="wikitable" align="center"

Genus

! Species

! Location

! Stratigraphic position

! Material

! Notes

! Images

Ankylosauria{{Cite journal |last1=Álvarez Nogueira |first1=Rodrigo |last2=Agnolín |first2=Federico L. |last3=Rozadilla |first3=Sebastián |last4=Aranciaga-Rolando |first4=Mauro |last5=Novas |first5=Fernando E. |date=2025-02-25 |title=Ankylosaurian remains from a new Campanian–Maastrichtian locality in Northern Patagonia, Argentina |journal=Alcheringa: An Australasian Journal of Palaeontology |language=en |pages=1–10 |doi=10.1080/03115518.2025.2467462 |issn=0311-5518}}

|Indeterminate

|Arriagada Farm

|Two teeth, five osteoderms, and a partial sacrum

|Fossil remains possibly belonging to a parankylosaur distinct from Patagopelta

Patagopelta

|P. cristata

| Salitral Moreno locality

|Lower

|Tooth, three posterior dorsal vertebrae, caudal vertebrae, two caudal centra, right femur, partial cervical half ring, and osteoderms.

| A parankylosaur{{Cite journal |last1=Soto Acuña |first1=Sergio |last2=Vargas |first2=Alexander O. |last3=Kaluza |first3=Jonatan |date=2024 |title=A new look at the first dinosaur discovered in Antarctica: reappraisal of Antarctopelta oliveroi (Ankylosauria: Parankylosauria) |journal=Advances in Polar Science |volume=35 |issue=1 |pages=78–107 |doi=10.12429/j.advps.2023.0036 |doi-access=free}}

| File:Patagopelta into the water.png

; Hadrosaurs

class="wikitable" align="center"
Genus ! Species ! Location ! Stratigraphic position ! Material ! Notes ! Images
Bonapartesaurus \|B. rionegrensis \| Salitral Moreno and Islas Malvinas. \|Lower \| A partial skeleton. \| A hadrosaur \|File:Bonapartesaurus rionegrensis.png
Kelumapusaura \| K. machi \| Cerro Matadero, Arriagada Farm \|Upper \| Partial skull, a cervical vertebrae, several sacrals, sternal rib and sternal plate, and multiple referred specimens found in a bonebed \| A saurolophine hadrosaur{{Cite journal\|last1=Rozadilla\|first1=S.\|last2=Brissón-Egli\|first2=F.\|last3=Agnolín\|first3=F.L.\|last4= Aranciaga-Rolando\|first4=A.M.\|last5=Novas\|first5=F.E.\|year=2022\| title=A new hadrosaurid (Dinosauria: Ornithischia) from the Late Cretaceous of northern Patagonia and the radiation of South American hadrosaurids\|journal=Journal of Systematic Palaeontology\|volume=19 \|issue=17 \|pages=1207–1235 \| doi=10.1080/14772019.2021.2020917\|s2cid=247122005 }} \|File:Kelumapusaura.jpg
Lapampasaurus \| L. cholinoi \| Islas Malvinas \|Lower \| Elements of the axial and appendicular skeleton of a subadult individual \| A hadrosaurCoria et al., 2012 \|
style="background:#E6E6E6;" \| Willinakaqe \| W. salitralensis \|Salitral Moreno site. \|Lower \|A right premaxilla. \| A saurolophine hadrosaurJuárez Valieri et al., 2010 \|

class="wikitable" align="center"

Genus

! Species

! Location

! Stratigraphic position

! Material

! Notes

! Images

Bonapartesaurus

|B. rionegrensis

| Salitral Moreno and Islas Malvinas.

|Lower

| A partial skeleton.

| A hadrosaur

|File:Bonapartesaurus rionegrensis.png

Kelumapusaura

| K. machi

| Cerro Matadero, Arriagada Farm

|Upper

| Partial skull, a cervical vertebrae, several sacrals, sternal rib and sternal plate, and multiple referred specimens found in a bonebed

| A saurolophine hadrosaur{{Cite journal|last1=Rozadilla|first1=S.|last2=Brissón-Egli|first2=F.|last3=Agnolín|first3=F.L.|last4= Aranciaga-Rolando|first4=A.M.|last5=Novas|first5=F.E.|year=2022| title=A new hadrosaurid (Dinosauria: Ornithischia) from the Late Cretaceous of northern Patagonia and the radiation of South American hadrosaurids|journal=Journal of Systematic Palaeontology|volume=19 |issue=17 |pages=1207–1235 | doi=10.1080/14772019.2021.2020917|s2cid=247122005 }}

|File:Kelumapusaura.jpg

Lapampasaurus

| L. cholinoi

| Islas Malvinas

|Lower

| Elements of the axial and appendicular skeleton of a subadult individual

| A hadrosaurCoria et al., 2012

style="background:#E6E6E6;"

| Willinakaqe

| W. salitralensis

|Salitral Moreno site.

|Lower

|A right premaxilla.

| A saurolophine hadrosaurJuárez Valieri et al., 2010

== Saurischians ==

;Sauropods

class="wikitable" align="center"
Genus ! Species ! Location ! Stratigraphic position ! Material ! Notes ! Images
Aeolosaurus \| Indeterminate \| \|Lower \| \| A titanosaurWeishampel et al., 2004, p.604 \| File:Aeolosaurus-rionegrinus-JD-2020-1.png
Bonatitan \| B.reigi"63.10 Provincia de Río Negro, Argentina; 4. Río Colorado Formation," in Weishampel, et al. (2004). Page 604. \| \|Lower \| Braincases, caudal vertebrae, and several limb elements \| A titanosaur \|
Menucocelsior \| M. arriagadai \| \|Lower \| Seventeen caudal vertebrae and several appendicular bones: a right humerus, a left fibula and some metapodial. \| A titanosaurRolando et al., 2022 \|
Panamericansaurus \| P. schroederi \| \| \| "Five tail vertebrata, sacral vertebrae, left humerus and rib fragments" \| A titanosaur"Table 13.1," in Weishampel, et al., 2004, p.269 \|
Pellegrinisaurus? \| P. powelli \| \|Lower (if it is from the formation) \| "Dorsal and caudal vertebrae, partial femur" \| A titanosaur \| File:Pellegrinisaurus Skeleton reconstruction.jpg
Rocasaurus \| R. muniozi \| \|Lower \| "Partial postcranial skeleton" \| A titanosaur"Table 13.1," in Weishampel, et al., 2004, p.270 \|

class="wikitable" align="center"

Genus

! Species

! Location

! Stratigraphic position

! Material

! Notes

! Images

Aeolosaurus

| Indeterminate

|Lower

| A titanosaurWeishampel et al., 2004, p.604

| File:Aeolosaurus-rionegrinus-JD-2020-1.png

Bonatitan

B.reigi"63.10 Provincia de Río Negro, Argentina; 4. Río Colorado Formation," in Weishampel, et al. (2004). Page 604.

|Lower

| Braincases, caudal vertebrae, and several limb elements

| A titanosaur

Menucocelsior

| M. arriagadai

|Lower

| Seventeen caudal vertebrae and several appendicular bones: a right humerus, a left fibula and some metapodial.

| A titanosaurRolando et al., 2022

Panamericansaurus

| P. schroederi

| "Five tail vertebrata, sacral vertebrae, left humerus and rib fragments"

| A titanosaur"Table 13.1," in Weishampel, et al., 2004, p.269

Pellegrinisaurus?

| P. powelli

|Lower (if it is from the formation)

| "Dorsal and caudal vertebrae, partial femur"

| A titanosaur

| File:Pellegrinisaurus Skeleton reconstruction.jpg

Rocasaurus

| R. muniozi

|Lower

| "Partial postcranial skeleton"

| A titanosaur"Table 13.1," in Weishampel, et al., 2004, p.270

== Theropods ==

class="wikitable" align="center"
Genus ! Species ! Location ! Stratigraphic position ! Material ! Notes ! Images
Austroraptor \| A. cabazai \| \| Lower \| A fragmentary skeleton including parts of the skull, lower jaw, a few neck and torso vertebrae, some ribs, a humerus, and assorted bones from both legs \| A dromaeosaurid \| File:Austroraptor Reconstruction.jpg
Bonapartenykus \|B. ultimus \| \|Upper \| A holotype consists of a mid-dorsal vertebra, both scapulocoracoids, left tibia and femur, left pubis articulated with the pubic peduncle of the ilium, the anterior blade of the left ilium, and two partially preserved eggs. \| An alvarezsauroid \| File:Bonapartenykus (life restoration).png
Lamarqueavis \| L. australis \| \|Lower \| "Right coracoid with damaged sternal and omal extremities, and lacking acrocoracoidal process" \| An ornithuranAgnolin, 2010 \|
Limenavis \| L. patagonica \| \|Lower \| "Partial forelimb" \| An ornithuran"Table 11.1," in Weishampel, et al., 2004, p.215 \|
Niebla \|N. antiqua \| \|Upper \|Braincase, fragmentary jaw and teeth, relatively complete scapulocoracoid, dorsal ribs, and incomplete vertebrae. \| An abelisaurid{{Cite journal\|last1=Aranciaga Rolando\|first1=Mauro\|last2=Cerroni\|first2=Mauricio A.\|last3=Garcia Marsà\|first3=Jordi A.\|last4=Agnolín\|first4=Federico l.\|last5=Motta\|first5=Matías J.\|last6=Rozadilla\|first6=Sebastián\|last7=Brisson Eglí\|first7=Federico\|last8=Novas\|first8=Fernando E.\|date=2020-10-14\|title=A new medium-sized abelisaurid (Theropoda, Dinosauria) from the late cretaceous (Maastrichtian) Allen Formation of Northern Patagonia, Argentina\|url=http://www.sciencedirect.com/science/article/pii/S0895981120304582\|journal=Journal of South American Earth Sciences\|volume=105\|language=en\|pages=102915\|doi=10.1016/j.jsames.2020.102915\|hdl=11336/150468 \|s2cid=225123133 \|issn=0895-9811\|hdl-access=free}} \| File:Abelisauridae-Niebla-antiqua.jpg
Quilmesaurus \| Q. curriei \| \|Upper \| Femur and distal tibia \| An abelisaurid"Table 4.1," in Weishampel, et al., 2004, p.77 \| File:Quilmesaurus curriei.jpg

class="wikitable" align="center"

Genus

! Species

! Location

! Stratigraphic position

! Material

! Notes

! Images

Austroraptor

| A. cabazai

| Lower

| A fragmentary skeleton including parts of the skull, lower jaw, a few neck and torso vertebrae, some ribs, a humerus, and assorted bones from both legs

| A dromaeosaurid

| File:Austroraptor Reconstruction.jpg

Bonapartenykus

|B. ultimus

|Upper

| A holotype consists of a mid-dorsal vertebra, both scapulocoracoids, left tibia and femur, left pubis articulated with the pubic peduncle of the ilium, the anterior blade of the left ilium, and two partially preserved eggs.

| An alvarezsauroid

| File:Bonapartenykus (life restoration).png

Lamarqueavis

| L. australis

|Lower

| "Right coracoid with damaged sternal and omal extremities, and lacking acrocoracoidal process"

| An ornithuranAgnolin, 2010

Limenavis

| L. patagonica

|Lower

| "Partial forelimb"

| An ornithuran"Table 11.1," in Weishampel, et al., 2004, p.215

Niebla

|N. antiqua

|Upper

|Braincase, fragmentary jaw and teeth, relatively complete scapulocoracoid, dorsal ribs, and incomplete vertebrae.

| An abelisaurid{{Cite journal|last1=Aranciaga Rolando|first1=Mauro|last2=Cerroni|first2=Mauricio A.|last3=Garcia Marsà|first3=Jordi A.|last4=Agnolín|first4=Federico l.|last5=Motta|first5=Matías J.|last6=Rozadilla|first6=Sebastián|last7=Brisson Eglí|first7=Federico|last8=Novas|first8=Fernando E.|date=2020-10-14|title=A new medium-sized abelisaurid (Theropoda, Dinosauria) from the late cretaceous (Maastrichtian) Allen Formation of Northern Patagonia, Argentina|url=http://www.sciencedirect.com/science/article/pii/S0895981120304582|journal=Journal of South American Earth Sciences|volume=105|language=en|pages=102915|doi=10.1016/j.jsames.2020.102915|hdl=11336/150468 |s2cid=225123133 |issn=0895-9811|hdl-access=free}}

| File:Abelisauridae-Niebla-antiqua.jpg

Quilmesaurus

| Q. curriei

|Upper

| Femur and distal tibia

| An abelisaurid"Table 4.1," in Weishampel, et al., 2004, p.77

| File:Quilmesaurus curriei.jpg

= Pterosaurs =

Fragmentary fossils are known from the formation.

class="wikitable" align="center"
Genus ! Species ! Location ! Stratigraphic position ! Material ! Notes ! Images
Aerotitan \| A. sudamericanus \| Bajo de Arriagada \| Upper \| Partial rostrum \| The first unambiguous azhdarchid from South-AmericaNovas et al., 2012 \|File:Aerotitan_sudamericanus.png

class="wikitable" align="center"

Genus

! Species

! Location

! Stratigraphic position

! Material

! Notes

! Images

Aerotitan

| A. sudamericanus

| Bajo de Arriagada

| Upper

| Partial rostrum

| The first unambiguous azhdarchid from South-AmericaNovas et al., 2012

|File:Aerotitan_sudamericanus.png

= Fish =

class="wikitable" align="center"
GenusMartinelli, A. and Forasiepi, A.M. (2004). [https://pdfs.semanticscholar.org/e205/bf9ca9f92e9911b20240160c7c553a38785f.pdf "Late Cretaceous vertebrates from Bajo de Santa Rosa (Allen Formation), Rio Negro province, Argentina, with the description of a new sauropod dinosaur (Titanosauridae)".] Revista del Museo Argentino de Ciencias Naturales 6(2): 257–305. ! Species ! Location ! Stratigraphic position ! Material ! Notes ! Images
Atlantoceratodus \| A. patagonicus \| \| \| 3 tooth plates \|A ceratorontiform lungfish{{Cite journal\|author=Federico Agnolin\|year=2010\|title=A new species of the genus Atlantoceratodus (Dipnoiformes: Ceratodontoidei) from the Uppermost Cretaceous of Patagonia and a brief overview of fossil dipnoans from the Cretaceous and Paleogene of South America \|journal=Brazilian Geographical Journal: Geosciences and Humanities Research Medium\|volume=1\|issue=2\|pages=162–210\|url=http://dialnet.unirioja.es/servlet/articulo?codigo=3638695 }} \|
Belonostomus \| B. lamarquensis \| \| \| \| A aspidorhynchid fish{{Cite journal\|author1=Sergio Bogan \|author2=Louis Taverne \|author3=Federico L. Agnolin \|year=2011 \|title=Description of a new aspidorhynchid fish, Belonostomus lamarquensis sp. nov. (Halecostomi, Aspidorhynchiformes), from the continental Upper Cretaceous of Patagonia, Argentina \|journal=Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Sciences de la Terre \|volume=81 \|pages=235–245 }} \|
Chondrichthyes \| indeterminate \| \| \| 11 vertebral centra \| \|
Diplomystidae \| indeterminate \| \| \| 4 incomplete pectoral spines \| \|
Siluriformes \| indeterminate \| \| \| 5 incomplete pectoral spines \| \|
Lepisosteidae \| indeterminate \| \| \| 6 vertebral centra \| \|
Teleostei \| indeterminate \| \| \| 10 isolated teeth \| \|
cf. Percichthyidae \| indeterminate \| \| \| 19 fragmentary vertebrae \| \|

class="wikitable" align="center"

GenusMartinelli, A. and Forasiepi, A.M. (2004). [https://pdfs.semanticscholar.org/e205/bf9ca9f92e9911b20240160c7c553a38785f.pdf "Late Cretaceous vertebrates from Bajo de Santa Rosa (Allen Formation), Rio Negro province, Argentina, with the description of a new sauropod dinosaur (Titanosauridae)".] Revista del Museo Argentino de Ciencias Naturales 6(2): 257–305.

! Species

! Location

! Stratigraphic position

! Material

! Notes

! Images

Atlantoceratodus

| A. patagonicus

| 3 tooth plates

|A ceratorontiform lungfish{{Cite journal|author=Federico Agnolin|year=2010|title=A new species of the genus Atlantoceratodus (Dipnoiformes: Ceratodontoidei) from the Uppermost Cretaceous of Patagonia and a brief overview of fossil dipnoans from the Cretaceous and Paleogene of South America |journal=Brazilian Geographical Journal: Geosciences and Humanities Research Medium|volume=1|issue=2|pages=162–210|url=http://dialnet.unirioja.es/servlet/articulo?codigo=3638695 }}

Belonostomus

| B. lamarquensis

| A aspidorhynchid fish{{Cite journal|author1=Sergio Bogan |author2=Louis Taverne |author3=Federico L. Agnolin |year=2011 |title=Description of a new aspidorhynchid fish, Belonostomus lamarquensis sp. nov. (Halecostomi, Aspidorhynchiformes), from the continental Upper Cretaceous of Patagonia, Argentina |journal=Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Sciences de la Terre |volume=81 |pages=235–245 }}

Chondrichthyes

| indeterminate

| 11 vertebral centra

Diplomystidae

| indeterminate

| 4 incomplete pectoral spines

Siluriformes

| indeterminate

| 5 incomplete pectoral spines

Lepisosteidae

| indeterminate

| 6 vertebral centra

Teleostei

| indeterminate

| 10 isolated teeth

cf. Percichthyidae

| indeterminate

| 19 fragmentary vertebrae

= Squamata =

class="wikitable" align="center"
Genus{{Cite journal\|last1=Garberoglio \|first1=F. F. \|last2=Gómez \|first2=R. O. \|last3=Apesteguía \|first3=S. \|last4=Rougier \|first4=G. W. \|year=2024 \|title=A Late Cretaceous lizard assemblage from the Allen Formation, northern Patagonia, Argentina \|journal=Historical Biology: An International Journal of Paleobiology \|pages=1–13 \|doi=10.1080/08912963.2024.2344789 }} ! Species ! Location ! Stratigraphic position ! Material ! Notes ! Images
Patagoniophis \| P. parvus \| \| \| incomplete trunk vertebra \| \|
Alamitophis \| A. argentinus \| \| \| incomplete trunk vertebra \| \|
Madtsoiidae \| indeterminate \| \| \| incomplete trunk vertebra \| \|
?Scincoidea \| indeterminate \| \| \| incomplete left maxilla \| \|
Pleurodonta \| indeterminate \| \| \| incomplete left maxilla \| \|
Teiioidea \| indeterminate \| \| \| incomplete right maxilla \| \|

class="wikitable" align="center"

Genus{{Cite journal|last1=Garberoglio |first1=F. F. |last2=Gómez |first2=R. O. |last3=Apesteguía |first3=S. |last4=Rougier |first4=G. W. |year=2024 |title=A Late Cretaceous lizard assemblage from the Allen Formation, northern Patagonia, Argentina |journal=Historical Biology: An International Journal of Paleobiology |pages=1–13 |doi=10.1080/08912963.2024.2344789 }}

! Species

! Location

! Stratigraphic position

! Material

! Notes

! Images

Patagoniophis

| P. parvus

| incomplete trunk vertebra

Alamitophis

| A. argentinus

| incomplete trunk vertebra

Madtsoiidae

| indeterminate

| incomplete trunk vertebra

?Scincoidea

| indeterminate

| incomplete left maxilla

Pleurodonta

| indeterminate

| incomplete left maxilla

Teiioidea

| indeterminate

| incomplete right maxilla

= Turtles =

class="wikitable" align="center"
Genus ! Species ! Location ! Stratigraphic position ! Material ! Notes ! Images
Iaremys \| I. batrachomorpha \| \| \| \| A chelid turtle{{Cite journal\|last1=Agnolín \|first1=F. L. \|last2=Aranciaga-Rolando \|first2=A. M. \|last3=Ortiz \|first3=R. \|title=New chelid turtle with a flattened skull from the Late Cretaceous of Northern Patagonia, Argentina \|year=2024 \|journal=Alcheringa: An Australasian Journal of Palaeontology \|doi=10.1080/03115518.2024.2427261 }} \|
Trapalcochelys \| T. sulcata \| \| \| \| A meiolaniform turtle{{Cite journal\|author =Juliana Sterli \|author2=Marcelo S. de la Fuente \|author3=Ignacio A. Cerda \|year=2013 \|title=A new species of meiolaniform turtle and a revision of the Late Cretaceous Meiolaniformes of South America \|journal=Ameghiniana \|volume=50 \|issue=2 \|pages=240–256 \|url=http://www.ameghiniana.org.ar/index.php/ameghiniana/article/view/582 \|doi=10.5710/amgh.16.01.2013.582\|s2cid=128701700 \|url-access=subscription }} \|
Yaminuechelys \| Y. gasperinii \| \| \| \| A chelid turtle \|

class="wikitable" align="center"

Genus

! Species

! Location

! Stratigraphic position

! Material

! Notes

! Images

Iaremys

| I. batrachomorpha

| A chelid turtle{{Cite journal|last1=Agnolín |first1=F. L. |last2=Aranciaga-Rolando |first2=A. M. |last3=Ortiz |first3=R. |title=New chelid turtle with a flattened skull from the Late Cretaceous of Northern Patagonia, Argentina |year=2024 |journal=Alcheringa: An Australasian Journal of Palaeontology |doi=10.1080/03115518.2024.2427261 }}

Trapalcochelys

| T. sulcata

| A meiolaniform turtle{{Cite journal|author =Juliana Sterli |author2=Marcelo S. de la Fuente |author3=Ignacio A. Cerda |year=2013 |title=A new species of meiolaniform turtle and a revision of the Late Cretaceous Meiolaniformes of South America |journal=Ameghiniana |volume=50 |issue=2 |pages=240–256 |url=http://www.ameghiniana.org.ar/index.php/ameghiniana/article/view/582 |doi=10.5710/amgh.16.01.2013.582|s2cid=128701700 |url-access=subscription }}

Yaminuechelys

| Y. gasperinii

| A chelid turtle

= Rhynchocephalia =

class="wikitable" align="center"
Genus ! Species ! Location ! Stratigraphic position ! Material ! Notes ! Images
Lamarquesaurus \| L. cabazai \| Cerro Tortuga \| \| \| align=center \| Apesteguía & Rougier, 2007, p.3

class="wikitable" align="center"

Genus

! Species

! Location

! Stratigraphic position

! Material

! Notes

! Images

Lamarquesaurus

| L. cabazai

| Cerro Tortuga

| align=center | Apesteguía & Rougier, 2007, p.3

= Plesiosauria =

class="wikitable" align="center"
Genus ! Species ! Location ! Stratigraphic position ! Material ! Notes ! Images
Kawanectes \| K. lafquenianum \| Quarry of the “Bentonitas Patagónicas” company \| Upper \| A partial skeleton consists of six cervical vertebrae, three dorsal vertebrae, three sacral vertebrae, nine caudal vertebrae, right femur, right humerus, ilium, one 216 mesopodial element, one caudal phalanx and one caudal rib . \| An elasmosaur. \| File: Kawanectes lafquenianum.png

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Genus

! Species

! Location

! Stratigraphic position

! Material

! Notes

! Images

Kawanectes

| K. lafquenianum

| Quarry of the “Bentonitas Patagónicas” company

| Upper

| A partial skeleton consists of six cervical vertebrae, three dorsal vertebrae, three sacral vertebrae, nine caudal vertebrae, right femur, right humerus, ilium, one 216 mesopodial element, one caudal phalanx and one caudal rib .

| An elasmosaur.

| File: Kawanectes lafquenianum.png

=Frogs=

Unnamed frogs belonging to the family Calyptocephalellidae and Leptodactylidae, and those with no family designation were also found.{{Cite journal |last1=Suazo Lara |first1=F. |last2=Gómez |first2=R. O. |date=2022-03-01 |title=In the shadow of dinosaurs: Late Cretaceous frogs are distinct components of a widespread tetrapod assemblage across Argentinean and Chilean Patagonia |url=https://www.sciencedirect.com/science/article/pii/S0195667121003335 |journal=Cretaceous Research |language=en |volume=131 |pages=105085 |doi=10.1016/j.cretres.2021.105085 |bibcode=2022CrRes.13105085S |s2cid=243482426 |issn=0195-6671|url-access=subscription }}

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Genus	Species	Location !Stratigraphic position !Material	Notes	Images
Calyptocephalella \| C. satan \| \| \| \|Calyptocephalellid frog{{cite journal \|author=Federico Agnolin \|year=2012 \|title=A new Calyptocephalellidae (Anura, Neobatrachia) from the Upper Cretaceous of Patagonia, Argentina, with comments on its systematic position \|url=http://revistas.usal.es/index.php/0211-8327/article/view/12820 \|journal=Studia Geologica Salmanticensia \|volume=48 \|issue=2 \|pages=129–178 }}
Kuruleufenia \|K. xenopoides \| \| \| \|Pipid frog{{Cite journal \|last=Gómez \|first=Raúl O. \|date=2016-07-01 \|title=A new pipid frog from the Upper Cretaceous of Patagonia and early evolution of crown-group Pipidae \|url=https://www.sciencedirect.com/science/article/pii/S0195667116300180 \|journal=Cretaceous Research \|language=en \|volume=62 \|pages=52–64 \|doi=10.1016/j.cretres.2016.02.006 \|bibcode=2016CrRes..62...52G \|hdl=11336/59544 \|issn=0195-6671\|hdl-access=free }} \|

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Genus

Species

Location

!Stratigraphic position

!Material

Notes

Images

Calyptocephalella

| C. satan

|Calyptocephalellid frog{{cite journal |author=Federico Agnolin |year=2012 |title=A new Calyptocephalellidae (Anura, Neobatrachia) from the Upper Cretaceous of Patagonia, Argentina, with comments on its systematic position |url=http://revistas.usal.es/index.php/0211-8327/article/view/12820 |journal=Studia Geologica Salmanticensia |volume=48 |issue=2 |pages=129–178 }}

Kuruleufenia

|K. xenopoides

|Pipid frog{{Cite journal |last=Gómez |first=Raúl O. |date=2016-07-01 |title=A new pipid frog from the Upper Cretaceous of Patagonia and early evolution of crown-group Pipidae |url=https://www.sciencedirect.com/science/article/pii/S0195667116300180 |journal=Cretaceous Research |language=en |volume=62 |pages=52–64 |doi=10.1016/j.cretres.2016.02.006 |bibcode=2016CrRes..62...52G |hdl=11336/59544 |issn=0195-6671|hdl-access=free }}

= Mammals =

The mammal fauna of the Allen Formation is known from seven teeth, which document the presence of several species.Rougier et al., 2009

Genus	Species	Location	Material	Notes	Images
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Mesungulatum \| M. lamarquensis \| Cerro Tortuga \| Two upper molars and a fragmentary lower molar \| A dryolestoid \|
Groebertherium \| G. stipanicici \| Cerro Tortuga \| One upper molar \| A dryolestoid \|
cf. Brandonia \| sp. \| Cerro Tortuga \| One lower molar \| A dryolestoid \|
Barberenia \| B. allenensis \| Cerro Tortuga \| One upper molariform \| A dryolestoid \|
Solanutheirum \| S. walshi \| Cerro Tortuga \| A right lower molar and left dentary fragment. \| A meridiolestid.{{Cite journal \|last1=Connelly \|first1=B. E. \|last2=Cardozo \|first2=M. S. \|last3=Montgomery \|first3=J. D. \|last4=Rougier \|first4=G. W. \|year=2024 \|title=New mammals from the Upper Cretaceous Allen Formation (Patagonia, Argentina) and reassessment of meridiolestidan diversity \|journal=Cretaceous Research \|volume=162 \|at=105935 \|doi=10.1016/j.cretres.2024.105935 }} \|
Trapalcotherium \| T. matuastensis \| Cerro Tortuga \| One first lower molar \| A gondwanathere \|

=Plants=

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Genus	Species	Location !Stratigraphic position !Material	Notes	Images
Podocarpoxylon \|P. mazzonii \| Valcheta Petrified Forest, Río Negro Province.{{Cite journal \|last1=Passalia \|first1=M. G. \|last2=Garrido \|first2=A. \|last3=Iglesias \|first3=A. \|last4=Vera \|first4=E. I. \|date=2022-10-14 \|title=The Valcheta Petrified Forest (Upper Cretaceous), Northern Patagonia, Argentina: A Geological And Paleobotanical Survey \|url=https://www.sciencedirect.com/science/article/pii/S0195667122002592 \|journal=Cretaceous Research \|volume=142 \|language=en \|pages=105395 \|doi=10.1016/j.cretres.2022.105395 \|s2cid=252964524 \|issn=0195-6671\|url-access=subscription }} \| \|Fossil wood \| \|

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Genus

Species

Location

!Stratigraphic position

!Material

Notes

Images

Podocarpoxylon

|P. mazzonii

| Valcheta Petrified Forest, Río Negro Province.{{Cite journal |last1=Passalia |first1=M. G. |last2=Garrido |first2=A. |last3=Iglesias |first3=A. |last4=Vera |first4=E. I. |date=2022-10-14 |title=The Valcheta Petrified Forest (Upper Cretaceous), Northern Patagonia, Argentina: A Geological And Paleobotanical Survey |url=https://www.sciencedirect.com/science/article/pii/S0195667122002592 |journal=Cretaceous Research |volume=142 |language=en |pages=105395 |doi=10.1016/j.cretres.2022.105395 |s2cid=252964524 |issn=0195-6671|url-access=subscription }}

|Fossil wood

References

= Bibliography =

{{citation |last=Agnolin |first=Federico L |year=2010 |title=An avian coracoid from the Upper Cretaceous of Patagonia, Argentina |url= http://campus.usal.es/~revistas_trabajo/index.php/0211-8327/article/view/7642/8861 |journal=Studia Geologica Salmanticensia |volume=46 |issue=2 |pages=99–119 |accessdate=2019-02-16}}
{{citation |last1=Apesteguía |first1=Sebastián |last2=Rougier |first2=Guillermo W. |year=2007 |title=A Late Campanian Sphenodontid Maxilla from Northern Patagonia |url= http://digitallibrary.amnh.org/bitstream/handle/2246/5874//v3/dspace/updateIngest/pdfs/N3581.pdf?sequence=1&isAllowed=y |journal=American Museum Novitates |issue=3581 |pages=1–12 |doi=10.1206/0003-0082(2007)3581[1:ALCSMF]2.0.CO;2 |accessdate=2019-03-30}}
{{citation |last1=Armas |first1=Paula |last2=Sánchez |first2=María Lidia |year=2015 |title=Hybrid coastal edges in the Neuquén Basin (Allen Formation, Upper Cretaceous, Argentina) |url= http://www.redalyc.org/pdf/1739/173936233006.pdf |journal=Andean Geology |volume=42 |pages=97–113 |accessdate=2018-10-02}}
{{citation |last1=Coria |first1=Rodolfo A. |last2=González Riga |first2=Bernardo |last3=Casadío |first3=Silvio |year=2012 |title=Un nuevo hadrosáurido (Dinosauria, Ornithopoda) de la Formación Allen, provincia de La Pampa, Argentina |url= https://www.researchgate.net/publication/273302264 |journal=Ameghiniana |volume= 49|issue= 4|pages= 552–572|doi=10.5710/AMGH.9.4.2012.487 |accessdate=2019-02-16}}
{{citation |last1=Juárez Valieri |first1=Rubén D. |last2=Haro |first2=José A. |last3=Fiorelli |first3=Lucas E. |last4=Calvo |first4=Jorge O. |year=2010 |title=A new hadrosauroid (Dinosauria: Ornithopoda) from the Allen Formation (Late Cretaceous) of Patagonia, Argentina |url= https://www.researchgate.net/publication/228457566 |journal=Revista del Museo Argentino de Ciencias Naturales |series=New Series |volume=11 |issue=2 |pages=217–231 |doi=10.22179/REVMACN.12.242 |accessdate=2019-02-16|hdl=11336/147903 |hdl-access=free }}
{{citation |last1=Novas |first1=F.E. |last2=Kundrat |first2=M. |last3=Agnolín |first3=F.L. |last4=Ezcurra |first4=M.N.D. |last5=Ahlberg |first5=P.E. |last6=Isasi |first6=M.P. |last7=Arriagada |first7=A. |last8=Chafrat |first8=P. |year=2012 |title=A new large pterosaur from the Late Cretaceous of Patagonia |url= http://www.museopatagonico.org.ar/files/aerotitan.pdf |journal=Journal of Vertebrate Paleontology |volume=32 |issue=6 |pages=1447 |doi=10.1080/02724634.2012.703979 |bibcode=2012JVPal..32.1447N |hdl=11336/98097 |accessdate=2019-02-16 |author1-link=Fernando Novas }}
{{citation |last1=Rougier |first1=G.W. |last2=Chornogubsky |first2=L. |last3=Casadio |first3=S. |last4=Paéz Arango |first4=N. |last5=Giallombardo |first5=A. |year=2009 |title=Mammals from the Allen Formation, Late Cretaceous, Argentina (subscription required) |url= https://www.researchgate.net/publication/232804456 |journal=Cretaceous Research |volume=30 |issue=1 |pages=223–238 |doi=10.1016/j.cretres.2008.07.006 |bibcode=2009CrRes..30..223R |hdl=11336/103413 |accessdate=2019-02-16|hdl-access=free }}
{{citation |last1=Salgado |first1=L. |last2=Coria |first2=R.A. |last3=Magalheas Ribeiro |first3=C.M. |last4=Garrido |first4=A. |last5=Rogers |first5=R. |last6=Simon |first6=M.E. |last7=Arcucci |first7=A.B. |last8=Rogers, Carabajal, A. P., Apesteguia, S., Fernandez, M., Garcia, R. A., and Talevi, M. |first8=K.C. |year=2007 |title=Upper Cretaceous dinosaur nesting sites of Rio Negro (Salitral Ojo de Agua and Salinas de Trapalco-Salitral de Santa Rosa), northern Patagonia, Argentina |url= https://www.researchgate.net/publication/223834880 |journal=Cretaceous Research |volume=28 |issue=3 |pages=392–404 |doi=10.1016/j.cretres.2006.06.007 |bibcode=2007CrRes..28..392S |hdl=11336/183909 |accessdate=2019-02-16|hdl-access=free }}
{{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 }}

Allen Formation

Description

Fossil content

= Dinosaurs =

== Ornithischians ==

== Saurischians ==

== Theropods ==

= Pterosaurs =

= Fish =

= Squamata =

= Turtles =

= Rhynchocephalia =

= Plesiosauria =

=Frogs=

= Mammals =

=Plants=

See also

References

= Bibliography =

Further reading