Paleobiota of the Cañadón Asfalto Formation

The Cañadón Asfalto Formation is a geological formation which dates to the Toarcian age of the Early Jurassic period of Argentina. The rocks of the formation preserve a diverse biota, including plants, dinosaurs, invertebrates, mammals and pterosaurs, among others. The formation is divided into two members: the lower Las Chacritas Member, and the overlying Puesto Almada member, though the latter has also been assigned to the overlying Cañadón Calcáreo Formation by some authors. The members are typically composed of fluvial-lacustrine deposits consisting of sandstones and shales, with a limestone carbonate evaporitic sequence also being present in the lower of the two.

Invertebrates

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Demospongiae

Palaeospongillidae reported from the Cañadon Asfalto Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Palaeospongilla[1]	P. chubutensis	Estancia Fossati locality	Las Chacritas Member	Isolated Specimens	A freshwater (Lacustrine) member of Palaeospongillidae (Spongillida Sponges). Represents the main lacustrine bottom inhabitant of the Chacritas Paleolake	Example of the living genus Spongilla. The genus Palaeospongilla was likely similar

Crustacea

Crustacea reported from the Cañadon Asfalto Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Carapacestheria[2][3][4]	C. taschi	Cañadón Asfalto Cañadón Lahuincó Cerro Bayo	Las Chacritas Member Puesto Almada Member	Isolated Valves	A freshwater (Lacustrine) member of Eosestheriidae (Spinicaudatan). Originally identified as Cyzicus (Euestheria) taschi. This genus is found in identical alkaline lacustrine settings in the also Toarcian Mawson Formation of Antarctica
Congestheriella[4][5]	C. rauhuti	Sierra de la Manea Estancia El Torito Cañadón Los Chivos	Puesto Almada Member	Isolated Valves	A freshwater (Lacustrine) member of Afrograptidae (Spinicaudatan). Given the stratigraphic uncertainty, it may come from the Cañadón Calcáreo Formation.
Darwinula[6]	D. magna D. spp.	Cañadón Asfalto Cañadón Lahuincó Cerro Bayo Cañadón Asfalto Quebrada Subsidiaria Estancia el Torito	Las Chacritas Member Puesto Almada Member	Isolated Valves	A freshwater (Lacustrine) member of Darwinulidae (Ostracod).
Eosolimnadiopsis[7]	E. spp.	Cerro Cóndor Estancia Fossati[8]	Las Chacritas Member	Isolated Valves	A freshwater (Lacustrine) member of Palaeolimnadiopseidae (Spinicaudatan).
Euestheria[9][3][4]	E. volkheimeri	Cerro Cóndor Cerro Bayo Alice Creek Quebrada Subsidiaria	Las Chacritas Member Puesto Almada Member	Isolated Valves	A freshwater (Lacustrine) member of Euestheriidae (Spinicaudatan).
Lioestheria[9][3][4]	C. (Lioestheria) sp. B C. (Lioestheria) sp. C	Cañadón Las Chacritas Colan Conhué Alice Creek	Las Chacritas Member Puesto Almada Member	Isolated Valves	A freshwater (Lacustrine) member of Fushunograptidae (Spinicaudatan).	Extant example of the Genus
Mandelstamia[9][6]	M.? spp.	Estancia El Torito	Puesto Almada Member	Isolated Valves	A freshwater (Lacustrine) member of Limnocytheridae (Ostracodan). Given the stratigraphic uncertainty, it may come from the Cañadón Calcáreo Formation
Metacypris[9][6]	M. sp.	Estancia El Torito	Puesto Almada Member	Isolated Valves	A freshwater (Lacustrine) member of Loxoconchidae (Ostracodan). Given the stratigraphic uncertainty, it may come from the Cañadón Calcáreo Formation.
Penthesilenula[9][6][10]	P. magna P. sarytirmenensis	Cañadón de la Angostura Estancia El Torito	Las Chacritas Member Puesto Almada Member	Isolated Valves	A freshwater (Lacustrine) member of Darwinulidae (Ostracodan). These species are characteristic of the Middle Jurassic of northern China and where used to correlate the age of the beds
Pseudestherites[9]	P. sp.	Estancia El Torito Cañadón Los Chivos	Puesto Almada Member	Isolated Valves	A freshwater (Lacustrine) member of Antronestheriidae (Spinicaudatan). Given the stratigraphic uncertainty, it may come from the Cañadón Calcáreo Formation.
Theryosinoecum[9][6]	T. barrancalensis minor	Estancia El Torito	Puesto Almada Member	Isolated Valves	A freshwater (Lacustrine) member of Cytheroidea (Ostracodan). Given the stratigraphic uncertainty, it may come from the Cañadón Calcáreo Formation.
Timiriasevia[9][6]	T. sp.	Estancia El Torito	Puesto Almada Member	Isolated Valves	A freshwater (Lacustrine) member of Limnocytheridae (Ostracodan). Given the stratigraphic uncertainty, it may come from the Cañadón Calcáreo Formation.
Wolfestheria[4]	W. patagoniensis W. smekali	Cañadón Asfalto Cañadón Lahuincó Estancia La Sin Rumbo	Las Chacritas Member Puesto Almada Member	Isolated Valves	A freshwater (Lacustrine) member of Fushunograptidae (Spinicaudatan).

Mollusca

Mollusca reported from the Cañadon Asfalto Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Corbicula[11]	C. spp.	Cerro Cóndor Cerro Bayo Estancia El Torito	Las Chacritas Member Puesto Almada Member	Isolated Shells	A freshwater (Lacustrine) member of Corbiculidae (Bivalve).	Extant example of the Genus
Cyanocyclas[11]	C. spp.	Cerro Cóndor Cerro Bayo Estancia El Torito	Las Chacritas Member Puesto Almada Member	Conchas Aisladas	A freshwater (Lacustrine) member of Corbiculidae (Bivalve).
Diplodon[9][11][12]	D. spix D. cf.matildensis D. cf.spix D. spp.	Cañadón Asfalto Cerro Caracoles Las Chacritas Cañadón Lahuincó Cañadón Miyanao Cerro Cóndor Cerro Bayo Alice Creek Quebrada Subsidiaria Estancia El Torito	Las Chacritas Member Puesto Almada Member	Isolated Shells	A freshwater (Lacustrine) member of Unionidae (Bivalve). The most abundant Bivalve genus on the Formation. Represents also some of the smallest-sized specimens recorded in the Mesozoic, what can be explained by potential environment stress.[12]	Extant example of the Genus
Nayadidae[13]	Indeterminate	Cañadón Asfalto Cañadón Lahuincó	Las Chacritas Member	Isolated Shells	A freshwater (Lacustrine) member of Unionidae (Bivalve).
Palaeomutela[3]	P. spp.	Las Chacritas	Las Chacritas Member	Isolated Shells	A freshwater (Lacustrine) member of Palaeomutelidae (Bivalve).
Potamolithus[3][13]	P.? spp.	Cañadón Asfalto Cerro Caracoles Las Chacritas Cañadón Lahuincó	Las Chacritas Member	Isolated Shells	A freshwater (Lacustrine) member of Tateidae (Snail).	Extant example of the Genus
Sphaeriidae[14]	Indeterminate	Cañadón Asfalto	Las Chacritas Member	Isolated Shells	A freshwater (Lacustrine) member of Sphaeriida (Bivalve).
Viviparus[11]	V. spp.	Cañadón Asfalto Cerro Caracoles Cañadón Lahuincó Cañadón Asfalto Quebrada Subsidiaria Estancia El Torito	Las Chacritas Member Puesto Almada Member	Isolated Shells	A freshwater (Lacustrine) member of Viviparidae (Snail).	Extant example of the Genus

Insecta

Insect eggs of unknown affinity were reported from several layers of the Estancia Fossati locality.^[1]

Insects reported from the Cañadon Asfalto Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Chironomidae[15]	Indeterminate	Gan Gan	Puesto Almada Member	Head capsules	Indeterminate Bittacidae (Migdes) remains, associated with lacustrine facies. Given the stratigraphic uncertainty, it may come from the Cañadón Calcáreo Formation	Extant member of the Family
Coleoptera[16]	Indeterminate	Cerro Cóndor Estancia Fossati[8] Estancia El Torito Estancia La Sin Rumbo	Las Chacritas Member Puesto Almada Member	Elytra and body remains	Indeterminate Beetle remains, associated with lacustrine facies	Extant example of the Group
Conchindusia[9][7]	C. isp.	Cerro Cóndor Gan Gan	Las Chacritas Member Puesto Almada Member	Imprints or compressed moulds of larval cases	Indeterminate Trichoptera (Caddisflies) Ichnofossils, associated with lacustrine facies. Larval cases made of conchostracan shells
Heteroptera[16]	Indeterminate	Cerro Cóndor Estancia Fossati Estancia El Torito Estancia La Sin Rumbo	Las Chacritas Member Puesto Almada Member	Fragmentary wings	Indeterminate Heteroptera remains, associated with lacustrine facies	Extant example of the Group
Neorthophlebidae[15]	Indeterminate	Gan Gan	Puesto Almada member	Wings and parts of body	Indeterminate Bittacidae (Scorpionfly) remains, associated with lacustrine facies. Given the stratigraphic uncertainty, it may come from the Cañadón Calcáreo Formation
Ostracindusia[9][7]	O. isp.	Cerro Cóndor Gan Gan	Las Chacritas Member Puesto Almada Member	Imprints or compressed moulds of larval cases	Indeterminate Trichoptera (Caddisflies) Ichnofossils, associated with lacustrine facies. Larval cases made of ostracodan shells
Terrindusia[9][17][7]	T. isp.	Cerro Cóndor Estancia Fossati[8] Gan Gan	Las Chacritas Member Puesto Almada Member	Imprints or compressed moulds of larval cases	Indeterminate Trichoptera (Caddisflies) Ichnofossils, associated with lacustrine facies. Larval cases made of clasts or terrigenous particles
Trichoptera[9][16][17]	Indeterminate	Cerro Cóndor Estancia Fossati Estancia El Torito Estancia La Sin Rumbo	Las Chacritas Member Puesto Almada Member	Wings and larval cases	Indeterminate Trichoptera (Caddisflies) remains, associated with lacustrine facies	Extant example of the Group

Vertebrates

Fish

Actinopteri reported from the Cañadon Asfalto Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Archaeomaenidae[18]	Indeterminate	Cerro Cóndor Cañadón Asfalto Cañadón Miyanao Estancia Fossati Localidad de Canela[19] Cañadón Asfalto Quebrada Subsidiaria	Las Chacritas Member	Isolated large median fin & Isolated Scales	A freshwater (Lacustrine) member of Archaeomaenidae (Teleostei). Maybe related to the genus Oreochima, coming from layers coeval, coregional, and of identical deposition of the Mawson Formation of Antarctica	Example of member of the family Archaeomaenidae, Archaeomaene

Amphibians

Amphibians reported from the Cañadon Asfalto Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Notobatrachus[20][21]	N. degiustoi[22] N. reigi Cf.N. spp.[19]	Cañadon Bagual Zitarrosa Cerro Cóndor Canela Queso Rallado	Las Chacritas Member	Many articulated, mostly complete skeletons Most of a partially articulated skeleton and skull	An early frog of the family Notobatrachidae. Notobatrachus degiustoi can be distinguished from N. reigsi by features of the skull. The presence of this anuran in several locations suggests local proliferation linked with lacustrine bodies

Turtles

Turtles reported from the Cañadon Asfalto Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Condorchelys[20][23][24]	C. antiqua C. cf.antiqua C. spp.	Queso Rallado Cañadon Bagual Chucrut Canela facies	Las Chacritas Member	Holotype: Most of a skull, carapace, and plastron. MPEF-PV 3163, left humerus MPEF-PV 3164, costal plate	A stem turtle (Mesochelydian) outside both extant groups, closely related with Kayentachelys aprix of North America and Indochelys spatulata of India. Likely occupied aquatic or semiaquatic niches.[23]
Testudinata[24]	Indeterminate	Canela facies	Las Chacritas Member	plastrons	Indeterminate Turtle remains

Lepidosaurs

Lepidosaurs reported from the Cañadon Asfalto Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Sphenocondor[25]	S. gracilis	Queso Rallado	Las Chacritas Member	Dentary	A Sphenodontian Rhynchocephalian, closely related with Godavarisaurus from the almost coeval Jurassic Kota Formation of India, maybe part of an endemic Gondwanan clade.[25]

Crocodylomorpha

Crocodyliformes reported from the Cañadón Asfalto Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Crocodylomorpha[26][27]	Indeterminate	Queso Rallado	Las Chacritas Member	Teeth & several isolated remains	Indeterminate crocodylomorph remains that represent small carnivorous vertebrates linked with lacustrine facies.

Pterosaurs

Pterosaurs reported from the Cañadón Asfalto Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Allkaruen[28]	A. koi	Canadón Carrizal	Las Chacritas Member	A braincase, as well as a mandible and cervical vertebrae.	A pterosaur either related with Breviquartossa or maybe even a sister group of monofenestratan (Wukongopteridae + Pterodactyloidea) pterosaurs
Ctenochasmatidae?[29]	Indeterminate	Queso Rallado	Not Determined	Isolated tooth	Resembles the teeth of Pterodaustro. The exact provenance of the specimen is unknown
Melkamter[29]	M. pateko	Queso Rallado	Las Chacritas Member	Partial skull and associated postcranial elements	A monofenestratan pterosaur, representing the oldest known record of this clade
Scaphognathinae?[30][31]	Indeterminate	Las Chacritas	Las Chacritas Member	Uncatalogued specimens, several mandibles, braincase, shoulder girdle, two humeri, several wing-finger phalanges	Indeterminate remains of a pterosaur, possibly a rhamphorhynchoid with a wingspan of about 1.5–2 metres (4.9–6.6 ft). The mandible morphology is similar to scaphognathines.[31]

Theropods

During a campaign conducted in early 2021, remains of a large theropod dinosaur were found near the town of Las Chacritas. In 2020 a new fossil locality was found, named Cañadón de las Huellas due to the large number of sauropod, and probably theropod, footprints on one of the canyon walls. In the same locality in 2021, articulated remains where recovered and represent at least one sauropod and one large theropod.^[32] At least four theropod morphotypes, including one with ceratosaur and another with Piatnitzkysauridae affinities, are known from the Cañadón Bagual.^[33]

Theropoda reported from the Cañadón Asfalto Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Asfaltovenator[34]	A. vialidadi	Cerro Condor	Las Chacritas Member	Nearly compete skull and largely complete front half of the skeleton forward of the hips, distal pubis and fermur and proximal fibula and tibia, partial foot	A probable early member of Allosauroidea
Averostra[35]	Indeterminate	Cerro Cóndor Puesto el Quemado Cerro Bayo	Las Chacritas Member	Isolated teeth: MPEF BA 182/08, BA 40/08, BA 09/80, BA 88/08, BA 252G+165/08 A, BA 252G+165/08 B, BA 252G+165/08 C	Theropod dinosaur teeth that resemble those assigned to the families Ceratosauridae, Megalosauridae and Abelisauridae
Ceratosauridae[36]	Indeterminate	Cañadon Bagual	Las Chacritas Member	A dentary with teeth in situ, MPEF-PV 6775	It resembles the dentary of Ceratosaurus
Condorraptor[30][37]	C. currumili	Las Chacritas	Las Chacritas Member	Partial articulated skeleton	A relative of Piatnitzkysaurus from the same formation, and a possible junior synonym of it as well.
Dromaeosauridae[35]	Indeterminate	Cerro Cóndor Puesto el Quemado Cerro Bayo	Las Chacritas Member	Isolated Teeth: MEPF BA 61/08, BA 103/08, BA 32/08 A, BA 32/08 B, BA 104/08, BA 226B/08, PV 3498, BA 29/08, BA51/08, BA 270/08 a, BA 270/08 b, BA 270/08 c	Theropod dinosaur teeth that resemble those assigned to the family Dromaeosauridae. Alternatively, they could belong to basal members of Coelurosauria
Eoabelisaurus[38]	E. mefi	Jugo Luco	Las Chacritas Member	A nearly complete articulated skeleton	A Neoceratosaur, that was suggested to be a basal member of Abelisauria, but also a member of Ceratosauridae
Megalosauridae[35]	Indeterminate	Cerro Cóndor Puesto el Quemado Cerro Bayo	Las Chacritas Member	Isolated Teeth: MPEF PV 1175, BA 66/08, PV 1356, PV 1357	Theropod dinosaur teeth that resemble those assigned to the family Megalosauridae.
Neotheropoda[35]	Indeterminate	Cerro Cóndor Puesto el Quemado Cerro Bayo	Las Chacritas Member	Isolated Teeth: MPEF BA 68/08, BA 92/08, PV 3499, BA 68/08, BA 183/08	Theropod dinosaur teeth that resemble those assigned to basal neotheropods, such as members of Coelophysoidea.
Piatnitzkysauridae[39][35]	Indeterminate	Cerro Cóndor Puesto el Quemado Cerro Bayo	Las Chacritas Member	Isolated Teeth & Cranial remains: MPEF 1717 CC 205, PV 3440A A, PV 3440A B, PV 3440A C, PV 3440A D, PV 3440A E, PV 3440A F, PV 3440A G	Theropod dinosaur teeth that resemble those assigned to members of Piatnitzkysauridae.
Piatnitzkysaurus[37][40]	P. floresi	Cerro Cóndor South	Las Chacritas Member	Two "fragmentary skulls with associated postcranium."[41]	Possible senior synonym of Condorraptor from the same formation.
Spinosauridae[35]	Indeterminate	Cerro Cóndor	Las Chacritas Member	Isolated Teeth : MEPF PV 1350	Theropod dinosaur teeth resembling those assigned to members of Spinosauridae. Alternatively, they could belong to members of Ceratosauria
Tetanurae[35]	Indeterminate	Cerro Cóndor Puesto el Quemado Cerro Bayo	Las Chacritas Member	Isolated Teeth : MEPF BA 84/08, BA 49/08 A, BA 49/08 B, BA 64/08, BA 65/08, BA 266/07	Theropod dinosaur teeth that resemble with those assigned to members of Megalosauridae and Dromaeosauridae
Theropoda[35]	Indeterminate	Cerro Cóndor	Las Chacritas Member	Isolated Teeth : MPEF PV 1640	"Outlier" tooth that doesn't fit in any previously known morphotype, maybe due to preservation
Theropodipedia[42]	Indeterminate	Cerro Cóndor	Las Chacritas Member	Footprints	Possible theropod footprints, unassigned to any concrete ichnogenus

Sauropodomorphs

A sediment tubular shaped mass enriched in organic matter, closely associated within the ventral area of articulated remains of a sauropod, was recovered at Cerro Condor, composed of a high concentration of pollen grains & cuticular fragments, mainly leaves of two morphotypes (Araucariaceae and Cheirolepidaceae), probably representing the gut contents of the sauropod, inferring a conifer-based diet.^[43]

Sauropodiformes reported from the Cañadón Asfalto Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Bagualia[44]	B. alba	Cañadon Bagual	Las Chacritas Member	The partial skeletons of three individuals	An early member of Eusauropoda, related with the African genus Spinophorosaurus
Diplodocidae[45][46]	Indeterminate	Cerro Condor Sur	Las Chacritas Member	MACN-CH 934: axial neural arches and spines, an ilium, a pubis, ?two or ?three ischia, and two maxillae	This specimen shows strong Diplodocidae affinities, yet it has been considered either a derived non-neosauropodan eusauropod (having resemblance with Lapparentosaurus in some characters) or even a basal neosauropod (also resembling Haplocanthosaurus)
Eusauropoda[46]	Indeterminate	Cerro Condor Sur	Las Chacritas Member	MACN-CH 230: three dorsal vertebrae	Likely a eusauropod, possibly a cetiosaurid. Smaller than other sauropod taxa found in the formation.
Patagosaurus[47][48]	P. fariasi	Cerro Condor	Las Chacritas Member	Many specimens, including a partial skull.	A non-neosauropodan eusauropodan member of Cetiosauridae. This genus represents the most abundant sauropod in the formation
Sauropodiformes[49]	Indeterminate	Queso Rallado, near Cerro Cóndor	Las Chacritas Member	Isolated Teeth: MPEF-PV 10860	An indeterminate Sauropodiform or a very basal sauropod or even dental material of Volkheimeria.[50]
Sauropoda[46]	Indeterminate	Cerro Condor Sur	Las Chacritas Member	MACN-CH 219, 223(+221), 231	Too fragmentary to be ascribed to any taxon, currently classified as Sauropoda indet.
Titanosauriformes[51]	Indeterminate	Queso Rallado, near Cerro Cóndor	Las Chacritas Member	Isolated Teeth: MPEF-PV 10606	An indeterminate Titanosauriform. It can be alternatively a basal Eusauropod. Possible relationships with Atlasaurus
Volkheimeria[46]	V. chubutensis	Cerro Cóndor South	Las Chacritas Member	"Partial skeleton consisting of presacral and sacral vertebrae, pelvis, [and] hindlimb."	Either a gravisaur or a sister taxon of the Indian genus Barapasaurus

Ornithischians

Ornithischians reported from the Cañadón Asfalto Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Cerapoda[52]	Indeterminate	Queso Rallado	Las Chacritas Member	Isolated ungual phalanx and Isolated Teeth: MPEF-PV 3818, MPEF-PV 3824, MEPF-PV 3820, MEPF-PV 3825, MEPF-PV 10861, MPEF-PV 10823, MPEF-PV 3821 & MPEF-PV 10864	An indeterminate Cerapodan with resemblances with Hypsilophodon. Some of the referred remains have been reclassified as Manidens material
Heterodontosauridae[52]	Indeterminate	Queso Rallado	Las Chacritas Member	Metapodials, caudal vertebrae, and isolated phalanges: MPEF-PV 3826	heterodontosaurid that cannot be compared with Manidens due to the lack of overlapping fossils.
Manidens[53][52]	M. condorensis	Queso Rallado Sitio Frenguelli Sitio Canela	Las Chacritas Member	Partial articulated specimen, skull & associated elements as well referred isolated teeth: MPEF-PV 3809, MPEF-PV 3211, MPEF-PV 3808, MPEF-PV 10867, MPEF-PV 1719, MPEF-PV 1786, MPEF-PV 1718, MPEF-PV 3810, MPEF-PV 3811, MPEF-PV 3812, MPEF-PV 3813, MPEF-PV 3814, MPEF-PV 3815, MPEF-PV 3816, MPEF-PV 10866	A primitive and small heterodontosaurid. Fossils attributed to this genus may have been at least partially arboreal. Principal component analysis found that the feet of Manidens were most similar to those of tree-perching birds.[54]
Ornithischia[52]	Indeterminate	Queso Rallado	Las Chacritas Member	Isolated teeth: MPEF-PV 3817, MPEFPV 3819, MPEF-PV 3822.	Not referable to any taxa beyond Ornithischia Indet.

Mammals

Mammals reported from the Cañadón Asfalto Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Allotheria[55]	Indeterminate	Queso Rallado	Las Chacritas Member	Isolated Teeth	An Allotherian whose affinities hasn't been tested
Argentoconodon[56]	A. fariasorum	Queso Rallado	Las Chacritas Member	MPEF-PV2362, fragmentary left maxilla, MPEF-PV2363 partial skeleton, MPEFPV2364 isolated complete right upper last molariform	A volaticotherian (Alticonodontinae), closely related to the Asian genus Volaticotherium, having similar postcraneal appearance, indicating possible gliding capabilities, yet better material is needed to prove it.[56]
Asfaltomylos[20][57]	A. patagonicus	Queso Rallado	Las Chacritas Member	MPEF PV 1671, complete lower maxilla	An Australosphenidan, related to Henosferus in Henosferidae.
Condorodon[55]	C. spanios	Queso Rallado	Las Chacritas Member	MPEF-PV 2365, isolated complete lower left molariform	An "amphilestid" triconodont, related with the late jurassic African Tendagurodon.[55]
Henosferus[20][58]	H. molus H. sp.	Queso Rallado Canela[19]	Las Chacritas Member	MPEF 2353 right lower jaw, MPEF 2354 Left lower jaw, MPEF 2357 Left lower jaw, referred MPEF 2355 isolated upper premolar	An Australosphenidan, related to Asfaltomylos in Henosferidae, being twice as large as this last one.[58]

Fungi

Genus	Species	Location	Stratigraphic position	Member	Material	Ecogroup	Palaeoclimate requirements	Notes
Annella[59]	A. capitata	Central Patagonia	Cañadon Lahuincó	Las Chacritas Member	Hypae and Miospores	Unknown: either Aquatic (Freshwater) or Parasitic	Unknown, suggested highly seasonality	A Fungus of uncertain relationships. This species is recovered in both coal seams and proximal prodelta sediments, making the assignation of a biome complex.[59]

Plants

According to a palynological study the dominant pollen was produced by the conifer families Cheirolepidiaceae (Classopollis) and Araucariaceae (mainly Araucariacites and Callialasporites), suggesting that warm-temperate and relatively humid conditions under highly seasonal climate prevailed during the depositional times of the unit. The abundance of Botryococcus supports the presence of a shallow lake with probably saline conditions.^[60] Locally, the Cañadón Asfalto represents a more poor record of the floras seen in the undeliying Lonco Tapial Formation, with its closest floras found on the Antarctic Peninsula Ellsworth Land Volcanic Group at Potter Peak, sharing Brachyphyllum spp. and Elatocladus confertus.^[61]

Phytoplankton

Possible freshwater "calcareous algae", associated with conifer shoots and aquatic invertebrates, have been reported from Cerro Caracoles.^[62]

Genus	Species	Location	Member	Material	Ecogroup	Palaeoclimate requirements	Notes	Images
Botryococcus[60][63][9]	B. sp. cf. B. braunii B. spp	Cañadon Lahuincó Cañadón Caracoles Cerro Bandera	Las Chacritas Member Puesto Almada Member	Algae	Aquatic (freshwater); Alkaline indicator	Highly seasonal climate	A freshwater algae of the family Botryococcaceae. This genus is the main indicator, due to its abundance, of the presence of a shallow lake with probably saline conditions, reaching in some samples about 96 to 70%.[60]	Extant specimen
Leiosphaeridia[60][63]	L. sp.	Cañadon Lahuincó Cañadón Caracoles	Las Chacritas Member	Zygospores	Aquatic (freshwater)	Temperate to warm; seasonal climate	Algae or Algae Acritarch of the family Prasinophyceae.
Ovoidites[60][63]	O. spp.	Cañadon Lahuincó Cañadón Caracoles	Las Chacritas Member	Zygospores	Aquatic (freshwater)	Temperate to warm; seasonal climate	Algae of the family Zygnemataceae	Extant Spirogyra; Ovoidites may be derived from a similar genus

Bryophyta

Genus	Species	Location	Member	Material	Ecogroup	Palaeoclimate requirements	Notes	Images
Antulsporites[60]	A. saevus	Cañadon Lahuincó Cañadón Caracoles	Las Chacritas Member	Spores	Upland and Riverside	Can withstand long periods of drought; seasonal climate	Affinities with the family Sphagnaceae in the Sphagnopsida. "Peat moss" spores, related to genera such as Sphagnum that can store large amounts of water.	Extant Sphagnum specimens; Stereisporites, Sculptisporis and Rogalskaisporites probably come from similar genera
Neoraistrickia[60]	N. cf. suratensis	Cañadon Lahuincó Cañadón Caracoles	Las Chacritas Member	Spores	Upland and Lowland	Warm to temperate, relatively wet	Affinities with the family Selaginellaceae and Lycopodiaceae in the Lycopsida.
Nevesisporites[60][63]	N. vallatus N. cf. undatus N. cf. radiatus	Cañadon Lahuincó Cañadón Caracoles	Las Chacritas Member	Spores	Upland and Riverside	Can withstand long periods of drought; seasonal climate	Affinities with Bryophyta.
Retitriletes[60]	R. austroclavatidites R. semimuris R. sp. 1	Cañadon Lahuincó Cañadón Caracoles	Las Chacritas Member	Spores	Upland and Lowland	Warm to temperate, relatively wet	Affinities with Bryophyta.
Stereisporites[60]	S. sp. cf. S. psilatus	Cañadon Lahuincó Cañadón Caracoles	Las Chacritas Member	Spores	Upland and Riverside	Can withstand long periods of drought; seasonal climate	Affinities with the family Sphagnaceae in the Sphagnopsida.

Equisetales

Genus	Species	Location	Member	Material	Ecogroup	Palaeoclimate requirements	Notes	Images
Equisetites[63][13][64][65]	E. approximatus E. spp.	Cañadon Asfalto Cañadon Lahuincó Paso de Indios Pomelo locality	Las Chacritas Member	Stems	Lowland and Riverside	Warm to temperate, relatively wet	Plants of the group Equisetales. Usually linked with riversides	Equisetites specimen

Pteridophyta

Genus	Species	Location	Member	Material	Ecogroup	Palaeoclimate requirements	Notes	Images
Baculatisporites[63]	B. comaumensis	Cañadon Lahuincó	Las Chacritas Member	Spores	Lowland and Riverside	Warm to temperate, relatively wet	Affinities with the family Osmundaceae in the Polypodiopsida. Near fluvial current ferns, related to the modern Osmunda regalis.	Extant Osmunda specimens; Baculatisporites probably come from similar genera or maybe a species from the genus
Biretisporites[60]	B. sp. A	Cañadon Lahuincó Cañadón Caracoles	Las Chacritas Member	Spores	Lowland and Riverside	Warm to temperate, relatively wet	Affinities with the Marattiaceae in the Polypodiopsida. Fern spores from low herbaceous flora.	Extant Marattia specimens; Marattisporites probably comes from similar genera
Cadargasporites[60]	C. sp. cf. C. reticulatus	Cañadon Lahuincó Cañadón Caracoles	Las Chacritas Member	Spores	Lowland and Riverside	Warm to temperate, relatively wet	Uncertain affinity Fern Spores Filicopsida incertae sedis
Cladophlebis[63][64][65]	C. grahami C. oblonga	Cañadon Asfalto Cañadon Lahuincó Paso de Indios Pomelo locality	Las Chacritas Member	Isolated Pinnae	Lowland and Riverside	Warm to temperate, relatively wet	Plants of the family Osmundaceae.
Clavatisporites[60]	C. spp.	Cañadon Lahuincó Cañadón Caracoles	Las Chacritas Member	Spores	Lowland and Riverside	Warm to temperate, relatively wet	Filicopsida incertae sedis
Deltoidospora[60]	D. australis D. minor	Cañadon Lahuincó	Las Chacritas Member	Spores	Upland, Lowland and Riverside	Warm to temperate, relatively wet	Affinities with the families Cyatheaceae/Dicksoniaceae Dipteridaceae/Matoniaceae in the Polypodiopsida.
Dictyophyllidites[60][63]	D. harrisii	Cañadon Lahuincó Cañadón Caracoles	Las Chacritas Member	Spores	Lowland and Riverside	Warm to temperate, relatively wet
Gleichenites[65]	G. cf.taquetrensis	Paso de Indios	Las Chacritas Member	Isolated Pinnae	Lowland and Riverside	Warm to temperate, relatively wet	Plants of the family Gleicheniales.
Ischyosporites[60]	I. marburgensis	Cañadon Lahuincó Cañadón Caracoles	Las Chacritas Member	Spores	Upland, Lowland Riverside	Warm to temperate, relatively wet	Affinities with the family Lygodiaceae and Schizaeaceae in the Polypodiopsida. Climbing or herbaceous fern spores.	Extant Lygodium; Lygodioisporites probably comes from similar genera or maybe a species from the genus
Klukisporites[60]	K. lacunus K. variegatus K. sp. cf. K. scaberis	Cañadon Lahuincó Cañadón Caracoles	Las Chacritas Member	Spores	Upland, Lowland Riverside	Warm to temperate, relatively wet
Obtusisporis[60]	O. modestus	Cañadon Lahuincó Cañadón Caracoles	Las Chacritas Member	Spores	Lowland and Riverside	Warm to temperate, relatively wet	Filicopsida incertae sedis
Rugulatisporites[63]	R. sp.	Cañadon Lahuincó	Las Chacritas Member	Spores	Lowland and Riverside	Warm to temperate, relatively wet	Affinities with the family Osmundaceae in the Polypodiopsida.
Sphenopteris[63][64]	S. patagonica S. hallei	Cañadon Asfalto Cañadon Lahuincó	Las Chacritas Member	Isolated Pinnae	Upland, Lowland and Riverside	Warm to temperate, relatively wet	Plants of the group Sphenopteridae, whose affinity for mesozoic specimens is uncertain, yet has been suggested to be fronds of Dicksoniaceae affinity
Todisporites[63]	T. minor	Cañadon Lahuincó	Las Chacritas Member	Spores	Upland	Warm to temperate, relatively wet. Can withstand long periods of drought; seasonal climate	Affinities with the family Osmundaceae in the Polypodiopsida.
Trilobosporites[60]	T. sp.	Cañadon Lahuincó	Las Chacritas Member	Spores	Upland, Lowland and Riverside	Warm to temperate, relatively wet	Affinities with the families Cyatheaceae/Dicksoniaceae Dipteridaceae/Matoniaceae in the Polypodiopsida.
Verrucosisporites[63]	V. varians	Cañadon Lahuincó	Las Chacritas Member	Spores	Upland	Can withstand long periods of drought; seasonal climate	Affinities with the family Osmundaceae in the Polypodiopsida.

Peltaspermales

Genus	Species	Location	Member	Material	Ecogroup	Palaeoclimate requirements	Notes	Images
Alisporites[60][63][9]	A. similis A. lowoodensis A. spp.	Cañadon Lahuincó Cañadón Caracoles Cerro Bandera	Las Chacritas Member Puesto Almada Member	Pollen	Riverside	Warm, can withstand long periods of drought; seasonal climate	Affinities with the families Peltaspermaceae, Corystospermaceae or Umkomasiaceae in the Peltaspermales. Pollen of uncertain provenance that can be derived from any of the members of the Peltaspermales.
Antevsia[66]	A. sp.	Pomelo locality	Las Chacritas Member	Pollen-bearing organs	Lowland and Riverside	Warm, can withstand long periods of drought; seasonal climate	Plants of the group Peltaspermaceae.
Archangelskya[63][64][65]	A. furcata	Cañadon Asfalto Cañadon Lahuincó	Las Chacritas Member	Isolated Pinnae	Lowland and Riverside	Warm, can withstand long periods of drought; seasonal climate	Plants of the group Pteridospermata
Lepidopteris[67][68]	L. scassoi	Pomelo locality A12 locality	Las Chacritas Member	Isolated Pinnae	Lowland and Riverside	Warm, can withstand long periods of drought; seasonal climate	Plants of the group Peltaspermaceae. This species represents the youngest record of the genus, by more than 20 Myr.
Peltaspermum[65][67]	P. sp.	Pomelo locality A12 locality	Las Chacritas Member	Ovuliferous Cones	Lowland and Riverside	Warm, can withstand long periods of drought; seasonal climate	Plants of the group Peltaspermaceae.
Vitreisporites[60]	V. pallidus	Cañadon Lahuincó	Las Chacritas Member	Pollen	Riverside	Warm, relatively wet	From the family Caytoniaceae in the Caytoniales. Caytoniaceae are a complex group of Mesozoic fossil floras that may be related to both Peltaspermales and Ginkgoaceae.

Cycadeoidopsida

Genus	Species	Location	Member	Material	Ecogroup	Palaeoclimate requirements	Notes	Images
Zamites[65][67]	Z. sp.	Pomelo locality A12 locality	Las Chacritas Member	Leaflets	Lowland and Riverside	Warm to temperate, can withstand long periods of drought; seasonal climate	Affinities with Bennettitales inside Cycadeoidopsida.

Czekanowskiales

Genus	Species	Location	Member	Material	Ecogroup	Palaeoclimate requirements	Notes	Images
Phoenicopsis[13][65]	P. sp.	Cañadon Asfalto Pomelo locality	Las Chacritas Member	Pollen Organs	Lowland and Riverside	Warm to temperate, can withstand long periods of drought; seasonal climate	Plants of the group Leptostrobales (Czekanowskiales). Gingko-like taxa

Gnetopsida

Genus	Species	Location	Member	Material	Ecogroup	Palaeoclimate requirements	Notes	Images
Ephedripites[63][9]	E. spp.	Cañadon Lahuincó Cerro Bandera	Las Chacritas Member Puesto Almada Member	Pollen	Lowland and Riverside	Warm to temperate, can withstand long periods of drought; seasonal climate	A Pollen Grain, affinities with Ephedraceae inside Gnetopsida.	Extant Ephedra, typical example of Ephedraceae. Equisetosporites probably come from a similar or a related Plant

Coniferophyta

Genus	Species	Location	Member	Material	Ecogroup	Palaeoclimate requirements	Notes	Images
Agathoxylon[69]	A. spp.	Cañadon Bagual	Las Chacritas Member	Fossil Wood	Upland, Lowland and Riverside	?Warm to temperate, relatively wet	Affinities with the family Araucariaceae in the Pinales.
Araucariacites[60][63][9]	A. australis A. fissus A. pergranulatus A. cf. A. pergranulatus A. sp. A	Cañadon Lahuincó Cañadón Caracoles Cerro Bandera	Las Chacritas Member Puesto Almada Member	Pollen	Upland, Lowland and Riverside	?Warm to temperate, relatively wet	Affinities with the family Araucariaceae in the Pinales. Conifer pollen from medium to large arboreal plants.
Araucaritites[63][64][65]	A. chuchensis A. spp.	Cañadon Asfalto Pomelo locality A12 locality Cañadon Lahuincó Estancia La Vistosa Paso de Indios	Las Chacritas Member	Ovuliferous scales	Upland, Lowland and Riverside	?Warm to temperate, relatively wet	Plants of the family Araucariaceae.
Athrotaxites[63][64][65]	A. ungeri	Cañadon Asfalto Cañadon Lahuincó	Las Chacritas Member	Branched shoots	Upland	?Warm to temperate, relatively wet	Plants of the family Taxodiaceae
Austrohamia[65][70]	A. asfaltensis	Cañadon Lahuincó	Las Chacritas Member	Branched shoots & Ovuliferous cones	Upland, Lowland and Riverside	?Warm to temperate, relatively wet	Plants of the family Cunninghamioideae. Along with the also Argentinian species A. minuta, this specimens represent the oldest fossil taxa that can be confidently assigned to Cupressaceae sensu lato
Brachyoxylon[65][71]	B. currumilii	Pomelo locality	Las Chacritas Member	Fossil Wood	Upland, Lowland and Riverside	?Warm to temperate, relatively wet	Plants of the family Araucariaceae or Cheirolepidiaceae
Brachyphyllum[63][64][65][67]	B. cf. lotenaense B. spp.	Cañadon Asfalto Cerro Caracoles Las Chacritas Pomelo locality A12 locality Cañadon Lahuincó Paso de Indios Canela locality	Las Chacritas Member	Branched shoots & Ovuliferous cones	Upland, Lowland and Riverside	?Warm to temperate, relatively wet	Plants of the family Araucariaceae or Cheirolepidiaceae
Callialasporites[60][63][9]	C. dampieri C. microvelatus C. turbatus C. minus C. sp. 1	Cañadon Lahuincó Cañadón Caracoles Cerro Bandera	Las Chacritas Member Puesto Almada Member	Pollen	Upland, Lowland and Riverside	?Warm to temperate, relatively wet	Affinities with the family Araucariaceae in the Pinales. Conifer pollen from medium to large arboreal plants.
Cerebropollenites[60][63][9]	C. macroverrucosus C. carlylensis C. mesozoicus C. sp. 1	Cañadon Lahuincó Cañadón Caracoles Cerro Bandera	Las Chacritas Member Puesto Almada Member	Pollen	Upland, Lowland and Riverside	?Warm to temperate, relatively wet	Affinities with both Sciadopityaceae and Miroviaceae in the Pinopsida. This pollen's resemblance to extant Sciadopitys suggest that Miroviaceae may be an extinct lineage of Sciadopityaceae-like plants.[72]	Extant Sciadopitys. Cerebropollenites likely come from a related plant
Classopollis[60][63][9]	C. classoides C. intrareticulatus C. simplex C. itunensis C. torosus	Cañadon Lahuincó Cañadón Caracoles Cerro Bandera	Las Chacritas Member Puesto Almada Member	Pollen	Lowland and Coastal lake	Warm to temperate, can withstand long periods of drought; seasonal climate	Affinities with the Hirmeriellaceae in the Pinopsida. Classopollis is the most abundant component of the assemblage, with ranges from 73 to 81.6% to 89.6%-89.7% in some samples.[60]
Elatoclaudus[63][64][65]	E. confertus E. jabalpurensis	Cañadon Asfalto Cañadon Lahuincó Pomelo locality	Las Chacritas Member	Branched shoots	Upland and Lowland	Warm to temperate, can withstand long periods of drought; seasonal climate	Plants of the family Cupressaceae
Exesipollenites[63]	E. sp.	Cañadon Lahuincó	Las Chacritas Member	Pollen	Lowland and Coastal lake	Warm to temperate, can withstand long periods of drought; seasonal climate	Affinities with the Hirmeriellaceae in the Pinopsida. Classopollis is the most abundant component of the assemblage, with ranges from 73 to 81.6% to 89.6%-89.7% in some samples.[60]
Indusiisporites[60]	I. parvisaccatus I. sp. 1 I. sp. 2 I. sp. 3	Cañadón Lahuincó Cañadón Caracoles	Las Chacritas Member	Pollen	Upland	Temperate, relatively dry	Affinities with the family Podocarpaceae. Pollen from diverse types of Podocarpaceous conifers, that include morphotypes similar to the low arbustive Microcachrys and the medium arbustive Lepidothamnus, likely linked with Upland settings
Inaperturopollenites[60]	I. indicus I. giganteus I. microgranulatus I. cf. reidi I. sp. 1 I. sp. 2	Cañadon Lahuincó	Las Chacritas Member	Pollen	Upland, Lowland and Riverside	?Warm to temperate, relatively wet	Affinities with the family Araucariaceae in the Pinales. Conifer pollen from medium to large arboreal plants.
Kaokoxylon[69]	K. spp.	Cañadon Bagual	Las Chacritas Member	Fossil Wood	Upland, Lowland and Riverside	?Warm to temperate, relatively wet	Affinities with the family Araucariaceae in the Pinales. Represents the youngest record of the genus, otherwise know from Permain or Triassic strata.[73]
Microcachryidites[63][9]	M. castellanosii M. antarcticus	Cañadón Lahuincó Cañadón Caracoles Cerro Bandera	Las Chacritas Member Puesto Almada Member	Pollen	Upland	Temperate, relatively dry	Affinities with the family Podocarpaceae. Pollen from Podocarpaceous conifers similar to the low arbustive Microcachrys	Extant Microcachrys Cone, example of the Podocarpaceae. Microcachryidites is similar to the pollen found on this genus
Pagiophyllum[63][64][65][67]	P. divaricatum P. fiestmantelli	Cañadon Asfalto Pomelo locality A12 locality Cañadon Lahuincó Paso de Indios Canela locality	Las Chacritas Member	Branched shoots	Lowland and Coastal lake	Warm to temperate, can withstand long periods of drought; seasonal climate	Plants of the family Araucariaceae or Cheirolepidiaceae
Pelourdea[13][65]	P. sp.	Cañadon Asfalto	Las Chacritas Member	Pollen Organs	Lowland and Coastal lake	Warm to temperate, can withstand long periods of drought; seasonal climate	Incertae sedis inside Coniferales, suggested as a member of its own family, the "Pelourdeaceae". A hygrophytic riparian conifer with herbaceous or shrubby habit. Some specimens are difficult to identify.
Perinopollenites[63]	P. elatoides	Cañadón Lahuincó	Las Chacritas Member	Pollen	Upland and Lowland	Warm to temperate; seasonal climate	Affinities with the family Cupressaceae in the Pinopsida. Pollen that resembles that of extant genera such as the genus Actinostrobus and Austrocedrus, probably derived from Upland environments.	Extant Austrocedrus. Exesipollenites and Perinopollenites maybe come from a related plant
Phrixipollenites[63]	P. sp.	Cañadón Lahuincó	Las Chacritas Member	Pollen	Upland	Temperate, relatively dry	Affinities with the family Podocarpaceae.
Pinuspollenites[60]	P. globosaccus	Cañadon Lahuincó Cañadón Caracoles	Las Chacritas Member	Pollen	Upland, Lowland and Riverside	?Warm to temperate, relatively wet	Affinities with the family Pinaceae in the Pinopsida. Conifer pollen from medium to large arboreal plants.
Podocarpidites[60][63]	P. verrucosus P. astrictus P. ellipticus P. multesimus P. variabilis P. sp. cf. P. radiatus P. sp. cf. P. verrucosus P. sp. 1	Cañadón Lahuincó Cañadón Caracoles	Las Chacritas Member	Pollen	Upland	Temperate, relatively dry	Affinities with the family Podocarpaceae in the Pinopsida.	Extant Podocarpus Cone, example of the Podocarpaceae. Podocarpidites is similar to the pollen found on this genus
Podocarpoxylon[69]	P. spp.	Cañadon Bagual	Las Chacritas Member	Fossil Wood	Upland, Lowland and Riverside	?Warm to temperate, relatively wet	Affinities with the family Podocarpaceae in the Pinopsida.
Podosporites[60]	P. variabilis P. sp. 1	Cañadón Lahuincó Cañadón Caracoles	Las Chacritas Member	Pollen	Upland	Temperate, relatively dry	Affinities with the family Podocarpaceae in the Pinopsida.
Protocupressinoxylon[69]	P. spp.	Cañadon Bagual	Las Chacritas Member	Fossil Wood	Upland, Lowland and Riverside	?Warm to temperate, relatively wet	Affinities with the family Hirmeriellaceae in the Pinopsida.
Prototaxoxylon[69]	P. spp.	Cañadon Bagual	Las Chacritas Member	Fossil Wood	Upland, Lowland and Riverside	?Warm to temperate, relatively wet	Affinities with the family Taxaceae in the Pinopsida. Alternatively, it can represent woods of the "Mesozoic Prototaxoxylon Group", an unnamed conifer family of possible Permian affinities.[74]

See also

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• Cañadón Asfalto Formation
• Cañadón Calcáreo Formation