Los Alamitos vertebrates, middle section (Cretaceous to of Argentina)

Also known as Los Alamitos vertebrates, middle section - green-coloured bed (mammals), Cerro Cuadrado, Arroyo Verde

Where: Río Negro, Argentina (42.1° S, 66.3° W: paleocoordinates 45.0° S, 52.3° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Los Alamitos Formation, Late/Upper Campanian to Late/Upper Campanian (83.5 - 66.0 Ma)

• middle section of formation includes vertebrate fossils distributed over about 30 meters of section

•Mammals: Middle section of Los Alamitos Formation - green-coloured bed just below the concretionary top of the Cerrito del Mamifero, Alamitian provincial age (Campanian sensu lato)

• group of beds-level stratigraphic resolution

Environment/lithology: lacustrine - large; bioturbated, concretionary, yellow siltstone and bioturbated, intraclastic sandstone

• dominant environment lacustrine, more brackish than fresh (clay flocculation in pelites). waters were oxygenated; lake permanent and shallow.

•The paleoenvironment according to Andreis (1987; and personnal communication) is that of a lacustrine environment mixed with shallow marine sediments, as indicated by the presnce of glauconite in some levels of the sequence.

• "Pelitic facies: includes dominant massive, laminated or rippled (rare) siltstones and claystones, with yellowish (lower part of the sequences) to reddish, orange, brown and purple hues (upper part), and massive sandstones. This rocks show typical paquidermis solution pattern which allow its recognition in outcrops. The non-calcareous pelites contains (lower half) almost all the vertebrate remains"

Size classes: macrofossils, mesofossils

Preservation: trace

Collected by J. F. Bonaparte, J. E. Powell in 1982-1983

Collection methods: quarrying, surface (float), surface (in situ), mechanical,

Primary reference: J. F. Bonaparte. 1984. Nuevas pruebas de la conexion fisica entre Sudamerica y Norteamerica en el Cretácico Tardio (Campaniano) [New evidences for the physical connection between South and North America in the Late Cretaceous (Campanian)]. Actas del III Congreso Argentino de Paleontologia y Bioestratigrafia 1:141-149 [M. Carrano/M. Carrano/M. Carrano]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 45087: authorized by Matthew Carrano, entered by Matthew Carrano on 04.10.2004, edited by Franco Aspromonte, Philip Mannion, Roger Benson, Jonathan Tennant and Evangelos Vlachos

Creative Commons license: CC BY (attribution)

Taxonomic list

Chondrichthyes
 Euselachiformes -
Batoidei indet.12 elasmobranch
MACN-RN 148, twelve vertebrae
Mammalia
 Allotheria -
Ferugliotherium sp.17 Bonaparte 1986 mammal
MACN-RN 249 (anterior upper premolar), and framgnetary left dentary
Ferugliotherium windhauseni n. gen. n. sp.7 Bonaparte 1986 mammal
MACN-RN 20 (holotype worn right m2) and specimen referred by Krause et al 1992: MACN-RN 701A, B (partial left i1s), 701C (partial i1), 253 (partial left m1), 702A–D (partial I2s), 248-251, MACN-RN 975; incisors and premolars only tentatively referred
 Allotheria - Sudamericidae
Gondwanatherium patagonicum n. gen. n. sp.6 Bonaparte 1986 mammal
MACN-RN 22 (holotype) 22-26, 228, 703-705, 970, 1024-1031
 Dryolestoidea -
Meridiolestida indet.15 Rougier et al. 2011 mammal
MACNPV-RN241, complete right upper premolariform
 Meridiolestida - Mesungulatidae
Mesungulatidae indet.15 Bonaparte 1986 mammal
MACN-RN 239, complete left P1; MACN-RN 240, complete left p1, MACN-RN 1135-1137
Mesungulatum houssayi n. gen. n. sp.8 Bonaparte and Soria 1985 mammal
MACN-RN 1, 3-12, 141, 181-184, 244
 Meridiolestida -
Austrotriconodon mckennai n. gen. n. sp.7
Austrotriconodon mckennai n. gen. n. sp.7 Bonaparte 1986 mammal
MACN-RN 21 (holotype) 234-238
 Dryolestida - Casamiquelidae
Rougietherium tricuspes n. gen. n. sp.9, Alamitherium bishopi n. gen. n. sp.9
Rougietherium tricuspes n. gen. n. sp.9 Bonaparte 2002 mammal
MACN-RN 162
Alamitherium bishopi n. gen. n. sp.9 Bonaparte 2002 mammal
MACN-RN 1034-1036
 Dryolestida -
Paraungulatum rectangularis n. gen. n. sp.9 Bonaparte 2002 mammal
MACN-RN 180 (left upper molar), 1141
 Dryolestoidea - Dryolestidae
Groebertherium indet.20 Bonaparte 1986 mammal
MACN-RN 185-200
Groebertherium stipanicici n. gen. n. sp.7 Bonaparte 1986 mammal
MACN-RN 13-17
Groebertherium novasi n. gen. n. sp.7 Bonaparte 1986 mammal
MACN-RN 18-19
 Marsupialia - Herpetotheriidae
Paratheria indet.8 Thomas 1887 marsupial
Reptilia
 Squamata - Madtsoiidae
"Madtsoiinae indet." = Madtsoiidae20, Alamitophis argentinus n. gen. n. sp.3, Patagoniophis parvus n. gen. n. sp.3, Rionegrophis madtsoioides n. gen. n. sp.3
"Madtsoiinae indet." = Madtsoiidae20 Hoffstetter 1961 snake
MACN-RN 201-202, 204-227
Alamitophis argentinus n. gen. n. sp.3 Albino 1986 snake
MACN-RN 27 (holotype) 27–31, 203
Patagoniophis parvus n. gen. n. sp.3 Albino 1986 snake
MACN-RN 33-35
Rionegrophis madtsoioides n. gen. n. sp.3 Albino 1986 snake
MACN-RN 32
 Testudinata -
Meiolaniformes indet.22 Sterli and de la Fuente 2013 turtle
MACN-RN 36-42, 65-76, 101
 Testudines - Panchelidae
Palaeophrynops patagonicus n. gen. n. sp.18
Palaeophrynops patagonicus n. gen. n. sp.18 Lapparent de Broin and de la Fuente 2001 sideneck turtle
 Testudines - Chelidae
Chelidae "indet. D"14 Gray 1825 sideneck turtle
The abundance is estimated, should be checked. MACN-RN 43-64, 77-100, 102-140
cf. Yaminuechelys sp.19 de la Fuente et al. 2001 sideneck turtle
The abundance is estimated, should be checked. MACN-RN 43-64, 77-100, 102-140
aff. Emydura sp.19 Bonaparte 1836 sideneck turtle
The abundance is estimated, should be checked. MACN-RN 43-64, 77-100, 102-140
 Eosuchia - Sphenodontidae
Sphenodontidae indet.4 Cope 1871 lepidosaur
MACN Pv RN1099c, 1100
Kawasphenodon expectatus n. gen. n. sp.4 Apesteguía 2005 lepidosaur
MACN Pv RN1098, 1099a-b
 Theropoda -
Ornithothoraces indet.11 Chiappe and Calvo 1994 avialan
MACN-RN 976 (partial cervical vertebra)
Ornithurae indet.2 avialan
MACN PV RN 1111 (distal end of left tibiotarsus, without distal condyles), MACN PV RN 1112 (distal end of left tibiotarsus with damaged medial condyle) and MACN PV RN 1113 (distal end of left tibiotarsus with complete distal condyles)
cf. Hesperornithiformes indet.2 Fürbringer 1888 avialan
MACN PV RN 1114 (distal end of left tibia)
Alamitornis minutus n. gen. n. sp.2 Agnolin and Martinelli 2009 avialan
MACN PV RN 1108 - holotype (proximal third of a left humerus) and referred material: MACN PV RN 1109 (five proximal extremes of right humeri of different individuals) and MACN PV RN 1110 (distal half of a left femur of a juvenile specimen)
Aves
 Aves -
Aves indet.2 bird
MACN PV RN 1103 (distal end of indeterminate pedal phalanx), MACN PV RN 1104 (distal end of pedal phalanx, probably II-2), MACN PV RN 1105 (pedal ungual of digit I) and MACN PV RN 1106 (manual ungual of digit I); MACN PV RN 1107 (pedal phalanx 1 of right digit II without its proximal end)
 Neornithes -
cf. Neornithes indet.2 bird
MACN PV RN 1115 (distal end of right tarsometatarsus without metatarsal IV and distal trochlea of metatarsal II)
Reptilia
 Saurischia - Titanosauridae
Titanosauridae indet.21 Lydekker 1885 titanosaurid
MACN-RN 1102, 1128
Titanosauridae indet.16 Lydekker 1885 titanosaurid
MACN-RN 147
 Ornithischia - Hadrosauridae
"Kritosaurus australis n. sp." = Huallasaurus australis10
"Kritosaurus australis n. sp." = Huallasaurus australis10 Bonaparte et al. 1984 hadrosaurine
MACN-RN 142-146, 826, 977-995, 997-998
Amphibia
 Salientia - Calyptocephalellidae
 Salientia - Pipidae
Kuruleufenia xenopoides23 Gómez 2016 clawed frog
Osteichthyes
 Dipnoi - Ceratodontidae
Atlantoceratodus patagonicus1 Agnolín 2010 lungfish
MACN PV RN157C, right lower tooth plate
"Ceratodus iheringi" = Atlantoceratodus iheringi12 Ameghino 1906 lungfish
MACN-RN 157-158, dental plates
Metaceratodus wichmanni n. sp.13 Apesteguía and Agnolin 2007 lungfish
MACN PV RN157A, left upper tooth plate
 Dipnoi - Ptychoceratodontidae
Ptychoceratodus cionei n. sp.5 Apesteguia et al. 2007 lungfish
MACN PV RN157A and 157B, two lower tooth plates
Actinopteri
 Spariformes - Sparidae
Sparidae indet.12 Cuvier 1817
"Lepidotes or Sparidae"
 Perciformes -
Percoidei indet.12 Bleeker 1859 perch-like fish
MACN-RN 155, tooth
 Teleostei -
Siluriformes indet.12 catfish
MACN-RN 154, 1139-1140, spines
 Siluriformes - Ariidae
cf. Ariidae indet.12 Berg 1958 Ariid catfish
MACN-RN 153, three pectoral spines fragments
 Siluriformes - Diplomystidae
cf. Diplomystidae indet.12 Eigenman 1890 catfish
MACN-RN 152, eight proximal fragments, eight central fragments and one pectoral spine
 Lepisosteiformes - Lepisosteidae
Lepisosteidae indet.12 Cuvier 1825 gar
MACN-RN 150, 156, six vertebrae, skulls fragments and 200 dermal scales
cf. Atractosteus sp.12 Rafinesque 1820 gar
MACN-RN 149, three teeth