# Salamanca Formation

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.
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. The formation yields abundant plant remains as well as fossils of invertebrates, marine macrofaunas, reptiles, and mammals. The formation consists primarily of estuarine to shallow marine deposits.
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. 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. The co-occurrence of palms, dicot woods with indistinct growth rings, and alligatorids, 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.

## Paleoflora

| Name | Species | Locality | Material | Notes |
| Agathis | A. immortalis | | Leaves, twigs, pollen cones, ovuliferous complexes, pollen, seeds | A conifer belonging to Araucariaceae. Oldest known species of Agathis |
| Akania | A. sp. | Palacio de los Loros | | A flowering plant of the family Akaniaceae |
| Azolla | A. keuja | Palacio de los Loros | | A fern belonging to the family Salviniaceae |
| Banaraphyllum | B. ovatum | Palacio de los Loros | | A flowering plant |
| Cissites | C. patagonicum | Palacio de los Loros | | A flowering plant belonging to Vitaceae, related to the modern genus Cissus |
| Classopollis | C. sp. | Palacio de los Loros | | Pollen belonging to the extinct conifer family Cheirolepidiaceae |
| Cunoniantha | C. bicarpellata | | | A flowering plant belonging to the family Cunoniaceae |
| Dryophyllum | D. australis | Palacio de los Loros | | A flowering plant |
| Fagophyllum | F. duseni | Palacio de los Loros | | Leaves, related to Fagaceae |
| Kirketapel | K. salamanquensis | | | A scale-leaved conifer belonging to the family Podocarpaceae. |
| Lacinipetalum | L. spectabilum | Palacio de los Loros | | A flowering plant belonging to the family Cunoniaceae |
| Laurophyllum | L. chubutensis L. piatnitzkyi | Palacio de los Loros | | A flowering plant belonging to the family Lauraceae |
| Lygodium | Sp. | | | A fern belonging to the Schizaeales, another indeterminate distinct fern is also present |
| Myrica | M. premira | Palacio de los Loros | | A flowering plant belonging to the family Myricaceae |
| Nothofagus | sp. | | Leaves | |
| Notiantha | N. grandensis | Rancho Grande | Flowers | A flowering plant belonging to the family Rhamnaceae |
| Palaeophytocrene | P. ga | Estancia Las Violetas | A fruit | A floweing plant belonging to the family Icacinaceae |
| Paracacioxylon | P frenguellii | Palacio de los Loros | Wood | A flowering plant belonging to the family Mimosoideae |
| Paranymphaea | P aristolochiaformis | Palacio de los Loros | | A flowering plant belonging to the family Nymphaeaceae |
| Sterculia | S. acuminataloba | Palacio de los Loros | | A flowering plant belonging to the family Malvaceae |
| Stephania | S. psittaca | Palacio de los Loros | | A flowering plant belonging to the family Menispermaceae |
| Suessenia | S. grandensis | Rancho Grande | Leaves | A flowering plant belonging to the family Rhamnaceae |
| Wilkinsoniphyllum | W. menispermoides | Palacio de los Loros | Leaves | A flowering plant belonging to the family Menispermaceae |
| Tripylocarpa | T. aestuaria | | Seed | A flowering plant belonging to the palm tribe Cocoseae |
| Volkheimerites | V. labyrinthus | | | Flowering plant pollen of uncertain placement |
| Fabaceae | | | | |
| Sapindaceae | | | | |
| Urticaceae | | | | |
| Rosaceae | | | | |
| Podocarpaceae | | | Leaves and cones | |

## Paleofauna
### Fish

| Name | Species | Locality | Material | Notes | Image |
| Xiphactinus | X. sp. | | | A member of the Ichthyodectiformes. | |

### Amphibians

| Name | Species | Locality | Material | Notes | Image |
| Gigantobatrachus | G. casamiquelai | Punta Peligro | | A frog | |
| Xerocephalella | X. sabrosa | Punta Peligro | | A frog belonging to the family Calyptocephalellidae. | |

### Reptiles
#### Testudines

| Name | Species | Locality | Notes |
| Hydromedusa | H. casamayorensis | Punta Peligro | A member of the family Chelidae. |
| Najadochelys | N. patagonica | Punta Peligro | |
| Peligrochelys | P. walshae | Punta Peligro | A member of Meiolaniformes |
| Salamanchelys | S. palaeocenica | Punta Peligro | A member of the family Chelidae. |
| Trionyx | T. argentina | Punta Peligro | A member of the family Trionychidae |
| Yaminuechelys | Y. maior | Punta Peligro | A member of the family Chelidae. |

#### Crocodylomorphs

| Name | Species | Locality | Notes |
| Eocaiman | E. palaeocenicus | Punta Peligro | A caimanine alligatorid. |
| Necrosuchus | N. ionensis | Estancia Las Violetas | A caimanine alligatorid. |
| Protocaiman | P. peligrensis | Punta Peligro | A caimanine alligatorid. |

#### Lepidosaurs

| Name | Species | Locality | Material | Notes | Image |
| Kawasphenodon | K. peligrensis | Punta Peligro | | A sphenodontian | |

### Mammals
#### Monotremes

| Name | Species | Locality | Material | Notes | Image |
| Monotrematum | M. sudamericanum | Punta Peligro | Teeth from the upper and lower jaws | A monotreme | |

#### Allotheres

| Name | Species | Locality | Material | Notes | Image |
| Sudamerica | S. ameghinoi | Punta Peligro | | A gondwanathere | |

#### Meridiolestidans

| Name | Species | Locality | Material | Notes | Image |
| Peligrotherium | P. tropicalis | Punta Peligro | | A member of the clade Mesungulatoidea. | |

#### Meridiungulates

| Name | Species | Locality | Notes |
| Escribania | E. chubutensis E. talonicuspsis | Punta Peligro | A member of the family Didolodontidae. |
| Raulvaccia | R. peligrensis | Punta Peligro | A member of the family Didolodontidae. |
| Requisia | R. vidmari | Punta Peligro | A member of the family Notonychopidae. |

#### Metatherians

| Name | Species | Locality | Material | Notes |
| Derorhynchus | D. aff. minutus | Punta Peligro | | A metatherian of uncertain affinities |
| Didelphopsis | Indeterminate | Punta Peligro | | A metatherian of uncertain affinities |
| ?Sparassodonta | Indeterminate | Punta Peligro | Astragalus | |
| Polydolopimorphia | Indeterminate | Punta Peligro | | Two taxa, one of which is a member of Bonapartheriidae |
| Metatheria | Indeterminate | Punta Peligro | Right petrosal (MPEF-PV 2235) | |

### Invertebrates

After unless otherwise noted
| Name | Species | Notes |
| Acesta | | A bivalve belonging to Limidae |
| Arca | | A bivalve belonging to Arcidae |
| ?Astarte | | A bivalve belonging to Astartidae |
| Aporrhaidae | Indeterminate | Gastropod |
| Austrophaera | | A bivalve |
| Barbatia | | A bivalve belonging to Arcidae |
| Bathytormus | | A bivalve belonging to Crassatellidae |
| Buccinidae | Four distinct genera | Gastropod |
| Cancellariidae | Indeterminate | A gastropod |
| Calyptraeidae | Indeterminate | Gastropod |
| Cardites | | A bivalve belonging to Carditidae |
| Cavoscala | | A gastropod belonging to Epitoniidae |
| Claibornicardia | | A bivalve belonging to Carditidae |
| Costacopluma | C. salamanca | A crab belonging to the family Retroplumidae |
| Crenilabium | | A gastropod belonging to Acteonidae |
| Cubitostrea | | A bivalve belonging to Ostreidae |
| Cucullaea | | Bivalve |
| Darwinices | | A gastropod belonging to Naticidae |
| ?Dosinia | | A bivalve belonging to Veneridae |
| Fusinus | | A gastropod belonging to Fasciolariidae |
| Fyfea | | A gastropod |
| Globisininae | Indeterminate | Gastropods belonging to the family Naticidae |
| Glycymerita | | A bivalve belonging to Glycymerididae |
| Gryphaostrea | | A bivalve |
| Gyroscala | | A gastropod belonging to Epitoniidae |
| Harpidae | Nov. Gen. | A gastropod |
| Heteroterma | | A gastropod belonging to Tudiclidae |
| ?Larma | | A bivalve belonging to Veneridae |
| Ledina | | A bivalve belonging to Nuculanidae |
| Leionucula | | A bivalve belonging to Nuculidae |
| Lucinidae | Indeterminate | Bivalve |
| Marwickia | | A bivalve belonging to Veneridae |
| Microfulgur | | A gastropod belonging to Fasciolariidae |
| Neilo | | A bivalve belonging to Malletiidae |
| Nucula | | A bivalve belonging to Nuculidae |
| Panopea | | A bivalve belonging to Hiatellidae |
| Patellogastropoda | Indeterminate | Gastropod |
| Perissodonta | | A gastropod belonging to Struthiolariidae |
| Phacoides | | A bivalve belonging to Lucinidae |
| Pinna | | A bivalve belonging to Pinnidae |
| Priscaphander | | A gastropod belonging to Scaphandridae |
| Priscophicus | | A gastropod belonging to Ficidae |
| Pseudomaura | | A gastropod |
| Pteromyrtea | | A bivalve belonging to Lucinidae |
| Pseudotylostoma | | A gastropod |
| Pycnodonte | | A bivalve belonging to Gryphaeidae |
| Ringiculidae | Indeterminate | A gastropod |
| Rocalaria | | A gastropod belonging to Fasciolariidae |
| Rotundicardia | | A bivalve belonging to Carditidae |
| Sacella | | A bivalve belonging to Nuculanidae |
| Spineilo | | A bivalve belonging to Malletiidae |
| Struthioptera | | A gastropod belonging to Aporrhaidae |
| Sulcobuccinum | | A gastropod belonging to Pseudolividae |
| Taioma | | A gastropod belonging to Fasciolariidae |
| Talochlamys | | A bivalve belonging to Pectinidae |
| Tejonia | | A gastropod belonging to Naticidae |
| Titomaya | T. longobucca & T. chalcedonica | A bivalve belonging to Venerida |
| Tornatellaea | | A gastropod belonging to Acteonidae |
| Turritellidae | Nov. gen. | A gastropod |
| Venericardia | | A bivalve belonging to Carditidae |
| Volutidae | Indeterminate | Gastropod |
| Yoldia | | A bivalve belonging to Yoldiidae |
| ?Zemacies | | A gastropod belonging to Borsoniidae |