Geologic formation in southern Patagonia, Argentina
Non-avian dinosaurs named from the Chorrillo Formation The Chorrillo Formation , also named as Chorillo Formation ,[ 1] is a Maastrichtian (Late Cretaceous Epoch, 72.1 - 66 million years ago) geologic formation in southern Patagonia , Argentina . The formation is more than 50 metres (160 ft) thick and underlies the Calafate Formation and rests on top of the La Irene Formation .[ 2]
Dinosaur remains are among the fossils that have been recovered from the formation.
Fossils recovered from the formation are:
Taxon Species Locality Stratigraphic position Material Notes Images Ankylosauria Indeterminate Five fragmentary caudal vertebrae, incomplete ribs, two incomplete humeri, and nine osteoderms Euiguanodontia Indeterminate Proximal end of a femur Hadrosauridae Indeterminate Two incomplete caudal centra Isasicursor I. santacrucensis Multiple specimens including teeth, several vertebrae, humerus, thigh bones, shoulder blades, and limbs An elasmarian ornithopod
Sauropods Taxon Species Locality Stratigraphic position Material Notes Images Nullotitan N. glaciaris Estancia Alta Vista A partial skeleton consisting of a third cervical vertebra, tail vertebrae, a neck rib, ribs, a left shoulder blade, the ends of a right thigh bone, a right shin, a right calf bone, and a right ankle bone A lithostrotian titanosaur Titanosauria Indeterminate Seven isolated teeth
Theropods Taxon Species Locality Stratigraphic position Material Notes Images Kookne K. yeutensis An incomplete right coracoid lacking sternal end and proximal end damaged An avialan theropod , possibly member of Neornithes Maip M. macrothorax La Anita Farm Axis, several dorsal and caudal vertebrae, cervical and dorsal ribs, gastralia, a left coracoid, fragmentary scapula, partial right pubis, and partial metatarsal The largest megaraptorid theropod of South America and possibly the largest member of this group
Megaraptoridae Indeterminate La Anita Farm Isolated teeth Noasauridae Indeterminate Isolated right pedal phalanx IV-2? Unenlagiidae Indeterminate An isolated dorsal vertebrae, pedal ungual of digit II and phalanx III-2 Yatenavis Y. ieujensis Estancia La Anita. Distal right humerus An enantiornithine bird
Taxon Species Locality Stratigraphic position Material Notes Images Anura Indeterminate Isolated tibiofibula Calyptocephalella C. sp. Incomplete left maxilla, incomplete right maxilla, incomplete right ilium, proximal right radioulna, left proximal end of tibiofibula and proximal half of urostyle Calyptocephalellidae Indeterminate A distal end of right humerus Pipoidea Indeterminate Distal end of right humerus
Taxon Species Locality Stratigraphic position Material Notes Images Lamniformes Indeterminate Isolated upper lateral tooth Teleostei Indeterminate Three crushing tooth crowns cf. Vidalamiinae Indeterminate Isolated tooth
Taxon Species Locality Stratigraphic position Material Notes Images Magallanodon M. baikashkenke Río de Las Chinas Valley and La Anita Farm Tentative first upper molariform, anterior end of a left dentary bearing part of its gliriform incisor, and upper mesial incisor from the right side A gondwanathere Mammalia Indeterminate Two isolated caudal vertebrae Patagorhynchus P. pascuali La Anita Farm Lower right molar attached to a fragment of the dentary A monotreme
Patagomaia P. chainko La Anita Farm Partial left acetabulum and ischium A large therian
Mosasaurs Taxon Species Locality Stratigraphic position Material Notes Images Mosasauridae Indeterminate
Rhynchocephalian Snakes Taxon Species Locality Stratigraphic position Material Notes Images Rionegrophis cf. R. madtsoioides A partial vertebra. Serpentes Indeterminate Partial mid-posterior vertebrae
Turtles Taxon Species Locality Stratigraphic position Material Notes Images Chelidae Indeterminate Hydromedusinae Indeterminate Left peripheral 3 or 4, bridge peripheral, fragment indet; bridge peripheral, right hypoplastron, buttress, plastral fragment and ?plastral fragment Meiolaniformes Indeterminate Distal end of a left humerus
Taxon Species Locality Stratigraphic position Material Notes Images Podocarpoxylon P. dusenii
Pollen Marenssi, Sergio A.; Casadío, Silvio; Santillana, Sergio N. (2003), "Estratigrafía y sedimentología de las unidades del Cretácico superior-Paleógeno aflorantes en la margen sureste del lago Viedma, provincia de Santa Cruz, Argentina" (PDF) , Revista de la Asociación Geológica Argentina , 58 : 403–416, retrieved 2018-08-30 Weishampel, David B. ; Dodson, Peter ; Osmólska, Halszka (2004), The Dinosauria, 2nd edition , Berkeley: University of California Press, pp. 1–880, ISBN 0-520-24209-2 , retrieved 2019-02-21 Novas, F.; Agnolin, F.; Rozadilla, S.; Aranciaga-Rolando, A.; Brissón-Eli, F.; Motta, M.; Cerroni, M.; Ezcurra, M.; Martinelli, A.; D'Angelo, J.; Álvarez-Herrera, J.; Gentil, A.; Bogan, S.; Chimento, N.; García-Marsà, J.; Lo Coco, G.; Miquel, S.; Brito, F.; Vera, E.; Loinaze, V.; Fernandez, M.; Salgado, L. (2019). "Paleontological discoveries in the Chorrillo Formation (upper Campanian-lower Maastrichtian, Upper Cretaceous), Santa Cruz Province, Patagonia, Argentina" . Revista del Museo Argentino de Ciencias Naturales . 21 (2): 217–293. doi :10.22179/REVMACN.21.655 . hdl :11336/122229 . Retrieved 2021-01-05 . Chimento, N.; Agnolin, F.; Tsuihiji, T.; Manabe, M.; Novas, F. (2020). "New record of a Mesozoic gondwanatherian mammaliaform from Southern Patagonia" . The Science of Nature . 107 (6): 49. Bibcode :2020SciNa.107...49C . doi :10.1007/s00114-020-01705-x . PMID 33211174 . S2CID 227066248 . Retrieved 2021-01-05 . Rozadilla, S.; Novas, F.; Agnolin, F.; Manabe, M.; Tsuihiji, T. (2021). "Ornithischian remains from the Chorrillo Formation (Upper Cretaceous), southern Patagonia, Argentina, and their implications on ornithischian paleobiogeography in the Southern Hemisphere" . Cretaceous Research . 125 : 104881. Bibcode :2021CrRes.12504881R . doi :10.1016/j.cretres.2021.104881 . Retrieved 2022-02-06 . Rolando, Alexis M. A.; Motta, Matias J.; Agnolín, Federico L; Manabe, Makoto; Tsuihiji, Takanobu; Novas, Fernando E. (2022). "A large Megaraptoridae (Theropoda: Coelurosauria) from Upper Cretaceous (Maastrichtian) of Patagonia, Argentina" . Scientific Reports . 12 (6318): 6318. Bibcode :2022NatSR..12.6318A . doi :10.1038/s41598-022-09272-z . PMC 9042913 . PMID 35474310 . Herrera, Gerardo Álvarez; Agnolín, Federico J.; Rozadilla, Sebastián; Lo Coco, Gastón E.; Manabe, Makoto; Tsuihiji, Takanobu; Novas, Fernando E. (2022). "New enantiornithine bird from the uppermost Cretaceous (Maastrichtian) of southern Patagonia, Argentina" . Cretaceous Research . 144 (105452): 105452. doi :10.1016/j.cretres.2022.105452 . S2CID 254804249 . Retrieved 2023-01-29 . J. E. Powell. 2003. Revision of South American titanosaurid dinosaurs: palaeobiological, palaeobiogeographical and phylogenetic aspects. Records of the Queen Victoria Museum Launceston 111:1-173