Pisco Formation
Geologic formation in Peru
The Pisco Formation is a geologic formation located in Peru, on the southern coastal desert of Ica and Arequipa. The approximately 640 metres (2,100 ft) thick formation was deposited in the Pisco Basin, spanning an age from the Late Miocene up to the Early Pliocene, roughly from 9.6 to 4.5 Ma. The tuffaceous sandstones, diatomaceous siltstones, conglomerates and dolomites were deposited in a lagoonal to near-shore environment, in bays similar to other Pacific South American formations as the Bahía Inglesa and Coquimbo Formations of Chile.
The Pisco Formation is considered one of the most important Lagerstätten sites, based on the large amount of exceptionally preserved marine fossils, including sharks (most notably megalodon), birds including penguins, whales and dolphins, marine crocodiles, and Thalassocnus, a marine giant sloths.
Other famous fossils from this site include the giant raptorial sperm whale Livyatan, the sperm whale relative Acrophyseter, and the walrus-like dolphin Odobenocetops.
01Description
The Pisco Formation of the Pisco Basin consists of tuffaceous sandstones, diatomaceous yellow to gray siltstones and a basal conglomerate. The formation is deposited from Pisco in the north to Yauca in the south. The northern portion is known as the Ocucaje Area and the southern part as the Sacaco Area. The total thickness of the formation is estimated at 640 metres (2,100 ft). The formation unconformably overlies the Chilcatay and Caballas Formations.
02Paleobiota of the Pisco Formation
The Pisco Formation has provided a rich resource of marine fauna, including marine mammals like cetaceans and seals, large fishes, reptiles, and penguins. It is also one of the richest sites in the world for fossil cetaceans, with close to 500 examples being found in the formation.
The oldest fossils of the aquatic sloth Thalassocnus (T. antiquus) come from the Aguada de Lomas horizon of the Pisco Formation and were dated at roughly 7 Ma. The youngest specimen (T. carolomartini) was found in the Sacaco horizon and dated to approximately 3 Ma. Thalassocnus was preyed upon by the probable apex predators of the environment, Livyatan and megalodon. The youngest strata belonging to the formation have been dated at 2 Ma, corresponding to the Early Pleistocene (Uquian). Fossils of the modern Humboldt penguin were found in these deposits at the Yauca locality.
| Color key | |||||||
|---|---|---|---|---|---|---|---|
| Taxon | Reclassified taxon | Taxon falsely reported as present | Dubious taxon or junior synonym | Ichnotaxon | Ootaxon | Morphotaxon | |
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Mollusks
Bivalves
| Taxa | Species | Description | Images | Notes |
|---|---|---|---|---|
| Dosinia | indet. sp. |
Polychaetes
| Taxa | Species | Description | Images | Notes |
|---|---|---|---|---|
| Diplochaetetes | D. mexicanus | A cirratulid bristle worm |
Gastropods
| Taxa | Species | Description | Images | Notes |
|---|---|---|---|---|
| Acanthina | A. obesa | |||
| A. triangularis | ||||
| Concholepas | C. kieneri | |||
| Herminespina | indet. sp. |
Fish
Bony fish
| Taxa | Species | Description | Images | Notes |
|---|---|---|---|---|
| Alosinae | indet. sp. | A type of herring | ||
| Centropomidae | C. aff. Psamoperca | A snook | ||
| Triglidae | indet. sp. | A type of sea robin | ||
| Xiphiidae | indet. sp. | A swordfish | ||
| Sardinops | S. humboldti | A sardine |
Rays
| Taxa | Species | Description | Images | Notes |
|---|---|---|---|---|
| Myliobatis | indet. sp. | A species of eagle ray |
Sharks
| Taxa | Species | Locality | Materials | Description | Images | Notes |
|---|---|---|---|---|---|---|
| Carcharias | C. taurus | Archaic sand tiger shark | ||||
| Carcharhinus | indet. sp. | A requiem shark | ||||
| Carcharodon | C. carcharias | Archaic great white shark and close relative, respectively | ||||
| C. hubbelli | Jaw, multiple teeth, and 45 vertebral centra | |||||
| C. hastalis | Fossilized jaws. | The broad-toothed "mako" | ||||
| C. plicatilis | ||||||
| Hexanchus | H. gigas | A cow shark | ||||
| Isurus | I. oxyrhinchus | Archaic shortfin mako | ||||
| Otodus | O. megalodon | Sub-Sacaco, Cerro Colorado, Aguada de Lomas, and El Jahuay | Multiple teeth, vertebrae, and dentition | The largest of the megatoothed sharks (Otodontidae) and of all fishes |
Reptiles
Crocodilians
| Taxa | Species | Locality | Materials | Description | Images | Notes |
|---|---|---|---|---|---|---|
| Eusuchia | indet. sp. | |||||
| Piscogavialis | P. jugaliperforatus | Sacaco | A partial skeleton and a skull. | A gryposuchine (gharial relative) | ||
| P. laberintoensis | Laberinto area, Ladera de Lisson Hill | A complete skull and mandible, along with postcranial elements | ||||
| Sacacosuchus | S. cordovai | Sacaco | A nearly complete skull | A gharial relative (Gavialidae) |
Turtles
| Taxa | Species | Locality | Materials | Description | Images | Notes |
|---|---|---|---|---|---|---|
| Pacifichelys | P. urbinai | A sea turtle (Cheloniidae) | ||||
| Chelonia | indet. sp. | Green sea turtle relative |
Birds
| Taxa | Species | Locality | Materials | Description | Images | Notes |
|---|---|---|---|---|---|---|
| Ciconiidae indet. | Gen. et sp. indet. | A stork | ||||
| Fulmarus | Indet. sp. | A petrel | ||||
| Morus | M. peruvianus | Sud-Sacaco | A set of limb elements | A relative of living gannets (Sulidae) | ||
| Perugyps | P. diazi | Sud-Sacaco | A limb element (right carpometacarpus). | A New World vulture (Cathartidae) | ||
| Pelagornis | P. sp. | Aguada de Lomas | Proximal carpometacarpus and right humerus ends | A pseudotoothed bird (Pelagornithidae) | ||
| Pelecanus | Indet. sp. | A pelican | ||||
| Phalacrocorax | P. aff. bougainvillii | A relative of the Guanay cormorant | ||||
| cf. Phalacrocorax sp. | Probable cormorant remains | |||||
| Rhamphastosula | R. aguierrei | Sud-Sacaco West | A cranium skull | A sulid bird with an enlarged beak | ||
| R. ramirezi | Sud-Sacaco West | A skull | ||||
| Spheniscus | S. humbodti | Sud Sacaco | Archaic Humboldt penguin | |||
| S. megarhampus | Sud Sacaco | A partial skeleton | Large-beaked banded penguin | |||
| S. muizoni | Cerro la Bruja | A partial skeleton. | The oldest banded penguin | |||
| S. urbinai | Sud-Sacaco West | A partial skeleton (partial skeleton with skull) | A larger banded penguin than S. muizoni | |||
| Sula | S. brandi | Cerro Colorado | A neurocranium lacking interorbital septum, lacrimals, palatines, pterygoids, jugals, quadrates, and right quadratojugal.Proximal portion of the beak, including most of the right dentary and angular. | Relatives of living boobies (Sulidae) | ||
| S. figueroae | Cerro Colorado | A skull and partial skeleton. | ||||
| S. magna | Sud Sacaco | A set of limb elements. | ||||
| S. sulita | Sud Sacaco | A limb element (coracoid) |
Mammals
Cetaceans
| Taxa | Species | Locality | Material | Description | Images | Notes |
|---|---|---|---|---|---|---|
| Acrophyseter | A. deinodon | Sud-Sacaco | A skull | A small raptorial physeteroid (sperm whale relative) | ||
| A. robustus | Cerro la Bruja | A skull | ||||
| Atocetus | A. iquensis | Cero la Bruja | A skull | A small kentriodontid whale | ||
| Australithax | A. intermedia | El Jahuay | A long-snouted porpoise (Phocoenidae) | |||
| Balaenoptera | B. siberi | Aguada de Lomas | A partial skeleton | Archaic rorqual (Balaenopteridae) | ||
| Belonodelphis | B. peruanus | Cerro la Bruja | A skull | An elongated oceanic dolphin (Delphinidae) | ||
| Brachydelphis | B. jahuayensis | El Jahuay | A partial skull | An early oceanic dolphin (Delphinidae) | ||
| B. mazeasi | El Jahuay | A partial skull | ||||
| Brujadelphis | B. ankylorostris | Cerro la Bruja | A skull with complete jaw | A toothed whale of uncertain relation (incertae sedis) | ||
| Hemisyntrachelus | H. oligodon | Sud-Sacaco | A skull | An orca relative | ||
| Incakujira | I. anillodefuego | Aguada de Lomas | A preserved skeleton | A small rorqual (Balaenopteridae) | ||
| I. fordycei | Aguada de Lomas | A preserved skeleton | ||||
| Kogia | K. danomurai | Sacaco | A partial skull consisting of partial cranium, preserving the facial and dorsolateral regions of the cranial vault, but lacking most of the rostrum and basicranium | Basal member of Kogia, the genus of pygmy and dwarf sperm whale | ||
| Koristocetus | K. pescei | Aguada de Lomas | A partial skull | A small kogiid | ||
| Livyatan | L. melvillei | Cerro Colorado | A partially preserved skull with teeth and lower jaw | A very large raptorial physeteroid with 36 centimetres (1.18 ft) teeth | ||
| Lomacetus | L. ginsburgi | Aguada de Lomas | A porpoise relative (Phocoenidae) | |||
| Mamaziphius | M. reyesi | Cerros la Mama y la Hija | A partial skull consisting of partial cranium lacking most of the rostrum, the zygomatic processes of the squamosal, the occipital condyles and the ear bones | An early beaked whale (Ziphiidae) | ||
| Messapicetus | M. gregarius | Cerro Colorado | A partial skeleton consists of a skull, mandibles, humeri, vertebrae, and scapula | An early beaked whale (Ziphiidae) | ||
| Mesokentriodon | M. protohumboldti | Santa rosa | A sub-complete cranium, which lacks part of the right orbit, part of the basicranium, the ear bones, and teeth | A kentriodontid dolphin. | ||
| Miminiacetus | M. barrancai | Aguada de Lomas | A completed jaw and teeth | A delphinidan | ||
| Miocaperea | M. pulchra | Aguada de Lomas | A partial skull | A cetothere whale | ||
| Ninoziphius | N. platyrostris | Sacaco | A partial skeleton | A giant beaked whale-relative | ||
| Odobenocetops | O. leptodon | Sacaco | A preserved skull | A tusked odontocete belonging to its unique family | ||
| O. peruvianus | Sacaco | A partial skull | ||||
| Piscobalaena | P. nana | Sud-Sacaco | A skull | A small cetothere | ||
| Piscocetus | P. sacaco | Sacaco | A partial skeleton | An extinct cetacean | ||
| Piscolithax | P. aenigmaticus | Aguada de Lomas | A partial skeleton | A porpoise relative (Phocoenidae) | ||
| Platyscaphokogia | P. landinii | Cerro Hueco la Zorra, | An incomplete skull lacking the tip of the rostrum and the basicranium. | An early beaked whale (Ziphiidae) | ||
| Pliopontos | P. littoralis | Sud-Sacaco | A partial skull | An early oceanic dolphin (Delphinidae) | ||
| Scaphokogia | S. cochlearis | Aguada de Lomas | An extinct kogiid |
Pinnipeds
| Taxa | Species | Locality | Material | Description | Images | Notes |
|---|---|---|---|---|---|---|
| Acrophoca | A. longirostirus | Sub-Sacaco | A partial skull. | Archaic southern seal (Monachinae) | ||
| Australophoca | A. changorum | Aguada de Lomas | A partial skeleton consists of incomplete right ulna, right radius, right and left humeri, and other unidentified remains. | A phocidae seal. | ||
| Hadrokirus | H. martini | Sub-Sacaco | A partial skull | Archaic southern seal (Monachinae) | ||
| Hydrarctos | H. lomasiensis | Sub-Sacaco | A skull. | A sea lion and fur seal relative (Otariidae) | ||
| Icaphoca | I. choristodon | Cerro La Bruja | A subcomplete skull with associated left and right mandibles, atlas, axis, third, fourth, and fifth cervical vertebrae. | Archaic southern seal (Monachinae) | ||
| Magophoca | M. brevirostris | Cerro la Bruja | A partial skeleton of a male. | Archaic southern seal (Monachinae) | ||
| Piscophoca | P. pacifica | Sub-Sacaco | A partial skull | Archaic southern seal (Monachinae) |
Xenarthrans
- Sloths
| Taxa | Species | Locality | Materials | Description | Images | Notes |
|---|---|---|---|---|---|---|
| Thalassocnus | T. antiquus | Aguada de Lomas | A partial skeleton including the skull, mandible, and most of the postcranial skeleton. | a semi-aquatic giant sloth inhabiting marine environments | ||
| T. carolomartini | Sacaco | An associated skull and mandible and two articulated hands, probably belonging to the same individual. | ||||
| T. littoralis | Sud-Sacaco | A skull with missing jugals. | ||||
| T. natans | Sud-Sacaco | A skull, mandible, and partial skeleton. |
03Correlations
Laventan
| Formation | Honda | Honda | Aisol | Cura-Mallín | Pisco | Ipururo | Pebas | Capadare | Urumaco | Inés | Paraná | Map |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Basin | VSM | Honda | San Rafael | Caldera | Pisco | Ucayali | Amazon | Falcón | Venezuela | Paraná | ||
| Country | Colombia | Bolivia | Argentina | Chile | Peru | Venezuela | Argentina | |||||
| Boreostemma | ||||||||||||
| Hapalops | ||||||||||||
| Miocochilius | ||||||||||||
| Theosodon | ||||||||||||
| Xenastrapotherium | ||||||||||||
| Mylodontidae | ||||||||||||
| Sparassodonta | ||||||||||||
| Primates | ||||||||||||
| Rodents | ||||||||||||
| Birds | ||||||||||||
| Terror birds | ||||||||||||
| Reptiles | ||||||||||||
| megalodon | ||||||||||||
| Flora | ||||||||||||
| Insects | ||||||||||||
| Environments | Fluvial | Fluvio-deltaic | Fluvio-lacustrine | Fluvio-deltaic | Fluvial | Laventan volcanoclastics Laventan fauna Laventan flora | ||||||
| Volcanic | Yes | |||||||||||
Sources and credits
This article is adapted from the Wikipedia article “Pisco Formation”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
Images, from Wikimedia Commons:
- Allomembers sedimentation of Pisco Formation.jpg by Claudio Di Celma, Elisa Malinverno, Giulia Bosio, Karen Gariboldi, Alberto Collareta, Anna Gioncada, Walter Landini, Pietro Paolo Pierantoni & Giovanni Bianucci, CC BY 4.0
- Diplochaetetes mexicanus.jpg by Tomáš Kočí, Giulia Bosio, Alberto Collareta, Rossana Sanfilippo, Boris Ekrt, Mario Urbina, Elisa Malinverno, CC BY 4.0
- Southern eagle ray.jpg by Unknown author, Public domain
- Sandtiger shark (Duane Raver).png by Raver Duane, U.S. Fish and Wildlife Service, Public domain
- White shark illustration.png by Píndaro Díaz-Jaimes, Manuel Uribe-Alcocer, Douglas H. Adams, Jose Miguel Rangel-Morales and Natalia J. Bayona-Vásquez, CC BY 4.0
- Isurus oxyrinchus.jpg by NMFS, E. Hoffmayer, S. Iglésias and R. McAuley, Public domain
- Otodus megalodon restoration.png by Oliver E. Demuth, CC BY 4.0
- Gannet (PSF).png by Pearson Scott Foresman, Public domain
- Pelagornis chilensis EF.jpg by El fosilmaníaco, CC BY-SA 3.0
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