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

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

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, Campanian to Campanian (83.6 - 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 Philip Mannion, Roger Benson, Jonathan Tennant and Evangelos Vlachos

Creative Commons license: CC BY (attribution)

Taxonomic list

unclassified
  -
cf. Hesperornithes indet.1
MACN PV RN 1114 (distal end of left tibia)
Chondrichthyes
 Euselachiformes -
Batoidei indet.11 elasmobranch
Actinopteri
 Perciformes -
Percoidei indet.11 Bleeker 1859 perch-like fish
 Spariformes - Sparidae
Sparidae indet.11 Cuvier 1817
"Lepidotes or Sparidae"
 Teleostei -
 Siluriformes - Diplomystidae
cf. Diplomystidae indet.11 Eigenman 1890 catfish
 Siluriformes - Ariidae
cf. Ariidae indet.11 Berg 1958 Ariid catfish
 Lepisosteiformes -
Lepidotes sp.11 Agassiz 1843 gar
"Lepisosteidae or Lepidotes"
 Lepisosteiformes - Lepisosteidae
Lepisosteidae indet.11 Cuvier 1825 gar
cf. Atractosteus sp.11 Rafinesque 1820 gar
Osteichthyes
 Dipnoi - Ceratodontidae
Ceratodus iheringi11 Ameghino 1906 lungfish
 Salientia - Pipidae
cf. Xenopus sp.4 Wagler 1827 clawed frog
 Salientia - Leptodactylidae
Leptodactylidae indet.4 Stirton 1953 frog
Reptilia
 Testudinata -
Meiolaniformes indet.18 Sterli and de la Fuente 2013 turtle
 Testudines - Panchelidae
Palaeophrynops patagonicus n. gen. n. sp.16 Lapparent de Broin and de la Fuente 2001 sideneck turtle
Chelidae "indet. B"12 sideneck turtle
Chelidae "indet. C"12 sideneck turtle
Chelidae "indet. D"12 sideneck turtle
 Saurischia - Titanosauridae
Titanosauridae indet.17 Lydekker 1885 titanosaurid
teeth, eggshells
Titanosauridae indet.14 Lydekker 1885 titanosaurid
MACN-RN 147
Aves
 Aves -
Aves indet.1 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)
 Ornithothoraces -
Ornithothoraces indet.10 Chiappe and Calvo 1994 bird
MACN-RN 976 (partial cervical vertebra)
 Ornithurae -
Ornithurae indet.1 bird
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. Neornithes indet.1 bird
MACN PV RN 1115 (distal end of right tarsometatarsus without metatarsal IV and distal trochlea of metatarsal II)
 Ornithothoraces -
Alamitornis minutus n. gen. n. sp.1
Alamitornis minutus n. gen. n. sp.1 Agnolin and Martinelli 2009 bird
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)
Reptilia
 Neornithischia - Hadrosauridae
"Kritosaurus australis n. sp." = Secernosaurus koerneri9
"Kritosaurus australis n. sp." = Secernosaurus koerneri9 Brett-Surman 1979 hadrosaurine
 Squamata - Madtsoiidae
Alamitophis rionegrinus n. gen. n. sp.2, Patagoniophis parvus n. gen. n. sp.2, Rionegrophis madtsoioides n. gen. n. sp.2
Alamitophis rionegrinus n. gen. n. sp.2 snake
MACN-RN 27–31
Patagoniophis parvus n. gen. n. sp.2 Albino 1986 snake
MACN-RN 33, 34
Rionegrophis madtsoioides n. gen. n. sp.2 Albino 1986 snake
MACN-RN 32
 Rhynchocephalia - Sphenodontidae
Sphenodontidae indet.3 Cope 1869 rhynchocephalian
MACN Pv RN1099c, 1100
 Rhynchocephalia -
Kawasphenodon expectatus n. gen. n. sp.3
Kawasphenodon expectatus n. gen. n. sp.3 Apesteguía 2005 rhynchocephalian
MACN Pv RN1098, 1099a-b
Mammalia
  - Bondesiidae
Bondesius ferox n. gen. n. sp.8
Bondesius ferox n. gen. n. sp.8 Bonaparte 1990 mammal
MACN-RN 161 (holotype, right lower molar crown); 162 (right upper molar crown)
 Dryolestida - Brandoniidae
Casamiquelia rionegrina n. gen. n. sp.8
Casamiquelia rionegrina n. gen. n. sp.8 Bonaparte 1990 mammal
MACN-RN 163 (holotype right upper molar), 229 (upper molar)
 Theriiformes - Dryolestidae
Groebertherium novasi n. gen. n. sp.5, Groebertherium stipanicici n. gen. n. sp.5
Groebertherium novasi n. gen. n. sp.5 Bonaparte 1986 mammal
MACN-RN 18-19
Groebertherium stipanicici n. gen. n. sp.5 Bonaparte 1986 mammal
MACN-RN 13-17
 Theriiformes -
Brandonia intermedia n. gen. n. sp.8, Barberenia araujoae n. gen. n. sp.8
Brandonia intermedia n. gen. n. sp.8 Bonaparte 1990 mammal
MACN-RN 164 (holotype right upper molar), 165 (right upper molar), 230 (left upper molar)
Barberenia araujoae n. gen. n. sp.8 Bonaparte 1990 mammal
MACN-RN 167 (holotype left upper molar), 167-170 (molars/jaw fragments))
 Dryolestoidea -
Meridiolestida indet.13 Rougier et al. 2011 mammal
MACNPV-RN241, complete right upper premolariform
 Meridiolestida -
Leonardus cuspidatus n. gen. n. sp.8 Bonaparte 1990 mammal
MACN-RN 231 (holotype partial maxilla), 231 (left upper molar)
Austrotriconodon mckennai n. gen. n. sp.5 Bonaparte 1986 mammal
MACNPV-RN21, complete lower right premolariform; Hypodigm. MACNPV-RN234, complete lower left premolariform
Austrotriconodon sepulvedai n. sp.8 Bonaparte 1992 mammal
MACN-RN 239 (holotype left lower molar), 240 (left ultimate lower premolar)
 Meridiolestida - Reigitheriidae
"Reigitherium bunodonta n. gen. n. sp." = Reigitherium bunodontum8
"Reigitherium bunodonta n. gen. n. sp." = Reigitherium bunodontum8 Bonaparte 1990 mammal
MACN-RN 173 (holotype left upper molar)
 Meridiolestida - Mesungulatidae
Mesungulatidae indet.13 Bonaparte 1986 mammal
MACNPV-RN239, complete left P1; MACNPV-RN240, complete left p1
Quirogatherium major n. gen. n. sp.8 Bonaparte 1990 mammal
MACN-RN 171 (holotype right upper molar)
Mesungulatum houssayi n. gen. n. sp.7 Bonaparte and Soria 1985 mammal
MACN-RN 1, 3-12, 141
 Theriiformes -
Paratheria indet.7 Thomas 1887 mammal
  - Ferugliotheriidae
"Ferugliotherium windhauseni n. gen. n. sp." = Ferugliotherium windhauseni5, "Vucetichia gracilis n. gen. n. sp." = Ferugliotherium windhauseni8
"Ferugliotherium windhauseni n. gen. n. sp." = Ferugliotherium windhauseni5 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), 251 (deciduous? anterior lower premolar), 253 (partial left m1), 702A–D (partial I2s), 250 (partial anterior upper premolar), 248 (right M1); incisors and premolars only tentatively referred
"Vucetichia gracilis n. gen. n. sp." = Ferugliotherium windhauseni8 Bonaparte 1986 mammal
MACN-RN 174 (holotype upper molar), 175 (upper molar)
 Allotheria - Sudamericidae
Gondwanatherium patagonicum n. gen. n. sp.6 Bonaparte 1986 mammal
 Multituberculata -
Multituberculata indet.15 multituberculate
MACN-RN 249 (anterior upper premolar), and framgnetary left dentary first reported as Ferugliotherium by Kielan-Jaworowska & Bonaparte (1996)