The Pisco Formation is a geologic formation located in Peru, on the southern coastal desert of Ica and Arequipa. The approximately 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,Brand et al., 2004Brand et al., 2011 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.De Muizon et al., 2003
Other famous fossils from this site include the giant raptorial sperm whale Livyatan,Lambert et al., 2010 the sperm whale relative Acrophyseter, and the walrus-like dolphin Odobenocetops.De Muizon & Domning, 2002
Description The Pisco Formation of the Pisco Basin consists of tuffaceous sandstones, diatomaceous yellow to gray siltstones and a basal conglomerate.Báez Gómez, 2006, p.65 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.Stucchi, 2007, p.368 The total thickness of the formation is estimated at .Altamirano Sierra, 2013, p.3 The formation unconformably overlies the Chilcatay and Caballas Formations.
Paleobiota 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.Báez Gómez, 2006, p.66 It is also one of the richest sites in the world for fossil cetaceans, with close to 500 examples being found in the formation.Poma Porras et al., 2009, p.86
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.De Muizon et al., 2004, p.287 Thalassocnus was preyed upon by the probable apex predators of the environment, Livyatan and megalodon.Parham & Pyenson, 2010, p.231Bianucci et al., 2015, p.543 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.Stucchi, 2007, p.370
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 NotesCarcharias C. taurus Archaic sand tiger shark Carcharhinus indet. sp. A requiem shark Carcharodon C. carchariasArchaic great white shark and close relative, respectivelyC. hubbelliJaw, multiple teeth, and 45 vertebral centra C. hastalis Fossilized jaws. The broad-toothed "mako"C. plicatilisHexanchus 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. laberintoensisLaberinto 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 NotesCiconiidae indet.Gen. et sp. indet. A stork Fulmarus Indet. sp. A petrel MorusM. peruvianus Sud-Sacaco A set of limb elements A relative of living gannets (Sulidae) Perugyps P. diazi Sud-SacacoA 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 beakR. ramirezi Sud-Sacaco West A skull Spheniscus S. humbodti Sud Sacaco Archaic Humboldt penguin Stucchi, 2007, p.370 S. megarhampus Sud Sacaco A partial skeletonLarge-beaked banded penguin S. muizoni Cerro la Bruja A partial skeleton. The oldest banded penguin Göhlich, 2007, p.287Stucchi, 2007, p.369 S. urbinai Sud-Sacaco West A partial skeleton (partial skeleton with skull) A larger banded penguin than S. muizoni SulaS. 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 NotesAcrophyseter A. deinodon Sud-Sacaco A skull A small raptorial physeteroid (sperm whale relative) A. robustus Cerro la Bruja A skullAtocetusA. 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 skullAn 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 skeletonKogiaK. 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 basicraniumBasal 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 teeth Lomacetus L. ginsburgi Aguada de Lomas A porpoise relative (Phocoenidae) MamaziphiusM. 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)MessapicetusM. gregariusCerro ColoradoA partial skeleton consists of a skull, mandibles, humeri, vertebrae, and scapula An early beaked whale (Ziphiidae)MesokentriodonM. protohumboldti Santa rosa A sub-complete cranium, which lacks part of the right orbit, part of the basicranium, the ear bones, and teethA 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) PlatyscaphokogiaP. 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. HadrokirusH. 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) IcaphocaI. 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)Dewaele, L.; de Muizon, C. (2025). "Icaphoca choristodon n. gen., n. sp., a new monachine seal (Carnivora, Mammalia) from the Neogene of Peru". Geodiversitas. 47 (11): 465–499. doi:10.5252/geodiversitas2025v47a11. 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 NotesThalassocnus 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 McDonald, H. & de Muizon, Christian. (2002). The cranial anatomy of Thalassocnus (Xenarthra, Mammalia), a derived nothrothere from the Neogene of the Pisco Formation (Peru). Journal of Vertebrate Paleontology. 22. 349-365. 10.1671/0272-4634(2002)022%5B0349:TCAOTX%5D2.0.CO;2. 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.
Correlations Laventan + Laventan correlations in South America 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 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 Volcanic Yes
See also Bahía Inglesa Formation, contemporaneous fossiliferous formation of Chile Castilletes Formation, contemporaneous fossiliferous formation of the Cocinetas Basin, Colombia Cerro Ballena, contemporaneous fossil site of the Bahía Inglesa Formation of Chile Coquimbo Formation, contemporaneous fossiliferous formation of Chile Collón Curá Formation, contemporaneous fossiliferous formation of Patagonia, Argentina Honda Group, contemporaneous fossiliferous formation of Colombia