A | B | C | D | E | F | G | H | CH | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
| Salamanca Formation | |
|---|---|
| Stratigraphic range: latest Maastrichtian-Danian (Tiupampan-Peligran) ~ | |
| Unit of | Río Chico Group |
| Underlies | Peñas Coloradas Formation (Río Chico Group) |
| Overlies | Lago Colhué Huapí Formation (Chubut Group) |
| Lithology | |
| Primary | Sandstone, mudstone |
| Other | Limestone |
| Location | |
| Country |  Argentina |
| Extent | Golfo San Jorge Basin |
| Type section | |
| Region | Chubut and Santa Cruz Provinces |
| Country | Argentina |
 Location of the Salamanca Formation within Argentina | |
The Salamanca Formation is a geologic formation in the Golfo San Jorge Basin of central Patagonia that yields well-preserved, well-dated fossils from the early Paleocene. Studies of these fossils are providing new data on plant and animal diversity following the end-Cretaceous extinction event.[1][2]
The Salamanca Formation crops out in the San Jorge Basin in southern Chubut and northern Santa Cruz provinces, Argentina, overlying the Cretaceous Chubut Group and is part of the Paleocene and Eocene Río Chico Group.[3][4][5][6] The formation yields abundant plant remains[7][8][9][10][11][12] as well as fossils of invertebrates, marine macrofaunas,[13] reptiles,[14][15][16][17][18] and mammals.[2][19][20][21][22][23][24][4][3] The formation consists primarily of estuarine to shallow marine deposits.[25][26]
Palynological analysis of the Salamanca Formation shows low floral diversity after the end-Cretaceous mass extinction, followed by a rapid recovery. 50% of all pollen types are angiosperms, whereas gymnosperms accounted for only ~13% of total richness; however, Classopollis pollen, representing the extinct conifer family Cheirolepidiaceae, is the most abundant palynomorph.[3] Wood assemblages from the Salamanca Formation. are dominated by conifers, but the presence of fossil angiosperm woods indicate that they were also part of the canopy.[8][9] The co-occurrence of palms, dicot woods with indistinct growth rings, and alligatorids,[15][16][17][18] indicates temperature remained above freezing year-round. The results of leaf physiognomic analyses indicate that the climate in the San Jorge Basin during the early Paleocene was warm subtropical.[27][28][29][30]
Paleoflora
| Name | Species | Locality | Material | Notes | Image |
|---|---|---|---|---|---|
| Agathis[31] | A. immortalis | Leaves, twigs, pollen cones, ovuliferous complexes, pollen, seeds | A conifer belonging to Araucariaceae. Oldest known species of Agathis[31] | ||
| Akania[10] | A. sp. | Palacio de los Loros | A flowering plant of the family Akaniaceae | ||
| Azolla[32] | A. keuja | Palacio de los Loros | A fern belonging to the family Salviniaceae | ||
| Banaraphyllum[10] | B. ovatum | Palacio de los Loros | A flowering plant | ||
| Cissites[10] | C. patagonicum | Palacio de los Loros | A flowering plant belonging to Vitaceae, related to the modern genus Cissus | ||
| Classopollis[3] | C. sp. | Palacio de los Loros | Pollen belonging to the extinct conifer family Cheirolepidiaceae | ||
| Cunoniantha[33] | C. bicarpellata | A flowering plant belonging to the family Cunoniaceae | |||
| Dryophyllum[10] | D. australis | Palacio de los Loros | A flowering plant | ||
| Fagophyllum[10] | F. duseni | Palacio de los Loros | Leaves, related to Fagaceae | ||
| Kirketapel[34] | K. salamanquensis | A scale-leaved conifer belonging to the family Podocarpaceae. | |||
| Lacinipetalum[35] | L. spectabilum | Palacio de los Loros | A flowering plant belonging to the family Cunoniaceae | ||
| Laurophyllum[10] | L. chubutensis
L. piatnitzkyi |
Palacio de los Loros | A flowering plant belonging to the family Lauraceae | ||
| Lygodium[10] | Sp. | A fern belonging to the Schizaeales, another indeterminate distinct fern is also present | |||
| Myrica[10] | M. premira | Palacio de los Loros | A flowering plant belonging to the family Myricaceae | ||
| Nothofagus[10] | sp. | Leaves | |||
| Notiantha[1] | N. grandensis | Rancho Grande | Flowers | A flowering plant belonging to the family Rhamnaceae | |
| Palaeophytocrene[36] | P. ga | Estancia Las Violetas | A fruit | A floweing plant belonging to the family Icacinaceae | |
| Paracacioxylon[8] | P frenguellii | Palacio de los Loros | Wood | A flowering plant belonging to the family Mimosoideae | |
| Paranymphaea[10] | P aristolochiaformis | Palacio de los Loros | A flowering plant belonging to the family Nymphaeaceae | ||
| Sterculia[10][37] | S. acuminataloba | Palacio de los Loros | A flowering plant belonging to the family Malvaceae | ||
| Stephania[38] | S. psittaca | Palacio de los Loros | A flowering plant belonging to the family Menispermaceae | ||
| Suessenia[1] | S. grandensis | Rancho Grande | Leaves | A flowering plant belonging to the family Rhamnaceae | |
| Wilkinsoniphyllum[38] | W. menispermoides | Palacio de los Loros | Leaves | A flowering plant belonging to the family Menispermaceae | |
| Tripylocarpa[39] | T. aestuaria | Seed | A flowering plant belonging to the palm tribe Cocoseae | ||
| Volkheimerites[40] | V. labyrinthus | Flowering plant pollen of uncertain placement | |||
| Fabaceae[10] | |||||
| Sapindaceae[10] | |||||
| Urticaceae[10] | |||||
| Rosaceae[10] | |||||
| Podocarpaceae[10] | Leaves and cones | ||||
Paleofauna
Fish
| Name | Species | Locality | Material | Notes | Image |
|---|---|---|---|---|---|
| Xiphactinus[41] | X. sp. | A member of the Ichthyodectiformes. |  |
Amphibians
| Name | Species | Locality | Material | Notes | Image |
|---|---|---|---|---|---|
| Calyptocephalella[42] | C. sabrosa | Punta Peligro | A frog belonging to the family Calyptocephalellidae. | ||
| Gigantobatrachus[43] | G. casamiquelai | Punta Peligro | A frog |
Reptiles
Testudines
| Name | Species | Locality | Material | Notes | Image |
|---|---|---|---|---|---|
| Hydromedusa[44] | H. casamayorensis | Punta Peligro | A member of the family Chelidae. | ||
| Najadochelys[45] | N. patagonica | Punta Peligro | |||
| Peligrochelys[46][47] | P. walshae | Punta Peligro | A member of Meiolaniformes | ||
| Salamanchelys[48] | S. palaeocenica | Punta Peligro | A member of the family Chelidae. | ||
| Trionyx | T. argentina | Punta Peligro | A member of the family Trionychidae | ||
| Yaminuechelys[45] | Y. maior | Punta Peligro | A member of the family Chelidae. |
Crocodylomorphs
| Name | Species | Locality | Material | Notes | Image |
|---|---|---|---|---|---|
| Eocaiman[15][16] | E. palaeocenicus | Punta Peligro | A caimanine alligatorid. | ||
| Necrosuchus[18] | N. ionensis | Estancia Las Violetas |  | ||
| Protocaiman[17] | P. peligrensis | Punta Peligro |  |
Lepidosaurs
| Name | Species | Locality | Material | Notes | Image |
|---|---|---|---|---|---|
| Kawasphenodon[49] | K. peligrensis | Punta Peligro | A sphenodontian |
Mammals
Monotremes
| Name | Species | Locality | Material | Notes | Image |
|---|---|---|---|---|---|
| Monotrematum[50][51] | M. sudamericanum | Punta Peligro | Teeth from the upper and lower jaws[52] | A monotreme |