Pisco Formation

Pisco Formation Stratigraphic range: Mid Miocene-Pliocene ~15–3 Ma PreЄ Є O S D C P T J K Pg N
Type	Geological formation
Unit of	Pisco Basin
Overlies	Chilcatay & Caballas Formations
Thickness	640 m (2,100 ft)
Lithology
Primary	Tuffaceous sandstone, diatomaceous siltstone
Other	Conglomerate, dolomite
Location
Coordinates	15°42′S 74°30′W / 15.7°S 74.5°W / -15.7; -74.5Coordinates: 15°42′S 74°30′W / 15.7°S 74.5°W / -15.7; -74.5
Approximate paleocoordinates	15°48′S 73°48′W / 15.8°S 73.8°W / -15.8; -73.8
Region	Arequipa & Ica Regions
Country	Peru
Extent	From Pisco to Yauca
Type section
Named for	Pisco
Outcrops of the 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 Middle Miocene up to the Late Pliocene, roughly from 15 to 3 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.

Several specialists consider the Pisco Formation one of the most important Lagerstätten,^[1][2] based on the large amount of exceptionally preserved marine fossils, including sharks (most notably Megalodon), penguins, whales, dolphins, birds, marine crocodiles and aquatic giant sloths.

Famous fossils found in these layers include the giant raptorial sperm whale Livyatan,^[3] the aquatic sloth Thalassocnus,^[4] the sperm whale Acrophyseter, and the walrus-like dolphin Odobenocetops.^[5]

Description

The Pisco Formation of the Pisco Basin consists of tuffaceous sandstones, diatomaceous yellow to gray siltstones and a basal conglomerate.^[6] 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.^[7] The total thickness of the formation is estimated at 640 metres (2,100 ft).^[8] The formation unconformably overlies the Chilcatay and Caballas Formations.

Fauna

The Pisco Formation has provided a rich resource of marine fauna, including marine mammals like cetaceans and seals, large fishes, reptiles, and penguins.^[9] It is also one of the richest sites in the world for fossil cetaceans, with close to 500 examples being found in the formation.^[10]

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.^[11] Thalassocnus was preyed upon by the probable apex predators of the environment, Livyatan and megalodon.^[12][13]

Vertebrates

Mammals
Taxa	Description	Images	Notes
Genus: Acrophoca A. longirostirus	A large pinniped thought to be the ancestor of the leopard seal		[14]
Genus: Acrophyseter A. deinodon A. robustus	A small raptorial physeteroid		[15]
Genus: Australophoca A. changorum	TBA		[16]
Genus: Balaeonoptera B. siberi	A baleen cetacean		[16]
Genus Brujadelphis B. ankylorostris	A river delphinid		[17]
Genus: Brachydelphis B. jahuayensis	An early delphinid		[16]
Genus: Hadrokirus H. martini	A species of true seal		[14]
Genus: Hemisyntrachelus H. oligodon	An early form of orca		[14]
Genus: Hydrarctos H. lomasiensis	TBA		[14]
Genus: Incakujira I. anillodefuego	A small baleen cetacean		[16]
Genus: Koristocetus K. pescei	A small sperm whale		[18]
Genus: Livyatan L. melvillei	An 18-meter long raptorial physeteroid with 36 centimetres (1.18 ft) teeth		[3]
Genus: Lomacetus L. ginsburgi	A cetacean		[16]
Genus: Miocaperea M. pulchra	A cetothere whale		[19]
Genus: Ninoziphius N. Platyrostris	TBA		[14]
Genus: Odobenocetops O. leptodon O. peruvianus	A cetacean with dual tusks		[5]
Genus: Piscobalaena P. nana	A small baleen whale		[14][20]
Genus: Piscocetus P. sacaco	An extinct cetacean		[21]
Genus: Piscolithax P. aenigmaticus	A porpoise		[14][16]
Genus: Piscophoca P. sp.	A seal		[20]
Genus: Pliopontos P. littoralis	An early delphinid		[14]
Genus: Scaphokogia S. cochlearis	An extinct pygmy sperm whale		[16]
Genus: Thalassocnus T. antiquus T. carolomartini T. littoralis T. natans	a semi-aquatic marine sloth		[4][14] [15][21]

Cartilaginous fishes
Taxa	Description	Images	Notes
Genus: Carcharocles Megalodon C. chubutensis	The largest of the megatoothed sharks (and of all fishes)		[9]
Genus: Carcharias C. taurus	The sand tiger shark.		[14]
Genus: Carcharhinus C. sp. indent	A requiem shark.		[9]
Genus: Carcharodon C. carcharias C. hubbelli	The great white shark		[21][14]
Genus: Cosmopolitodus C. hastalis	The broad-toothed mako		[9]
Genus: Hexanchus H. gigas	A cow shark.		[21]
Genus: Isurus I. oxyrhincus	The shortfin mako		[16]
Genus: Myliobatis M. sp	A species of eagle ray		[9]

Bony fishes
Taxa	Description	Images	Notes
Genus: Alosinae A. indent	A type of herring.		[9]
Genus: Centropomidae C. aff. Psamoperca	A snook fish.		[9]
Genus: Triglidae T. indent	A type of sea robin		[9]
Genus: Xiphiidae X. ident	A sword fish		[9]
Genus: Xiphiorhynchus X. sp	A ray-finned fish		[9]
Genus: Sardinops S. sp.	A sardine		[20]

Birds
Taxa	Description	Images	Notes
Genus: Spheniscus S. humboldti S. megarhampus S. urbinai	The banded penguin		[22]
Genus: Ramphastosula R. aguierrei R. ramirezi			[14][23]
Genus: Sula S. brandi S. magna S. sulita			[15][24]
Morus peruvianus			[15]
Perugyps diazi			[15]
Fulmarus sp.			[14]
Pelagornis sp.			[16]
Pelecanus sp.			[25]
Genus: Phalacrocorax P. aff. bougainvillii cf. Phalacrocorax sp.			[14][26]

Reptiles
Taxa	Description	Images	Notes
Genus: Piscogavialis P. jugaliperforatus	A gryposuchine gavialid crocodylian		[15][20]
Genus: Pacifichelys P. urbinai	A sea turtle		[12][27]
Chelonia sp., Cheloniidae indet.			[9]
Eusuchia sp.			[14]

See also

• Abanico Formation
• Castilletes Formation
• Honda Group
• Navidad Formation
• Pebas Formation
• Urumaco

References

Further reading

Wikimedia Commons has media related to Pisco Formation.

• A. Alván, J. Apolín, and C. Chacaltana. 2004. Los dientes de Seláceos (Condrichthyies) y su aplicación estratigráfica en Las Lomas de Ullujaya (Ica, Perú). XIII Congreso Peruano de Geología. Resúmenes Extendidos 595-598
• A. Collareta, O. Lambert, W. Landini, C. Di Celma, E. Malinverno, R. Varas-Malca, M. Urbina and G. Bianucci. 2017. Did the giant extinct shark Carcharocles megalodon target small prey? Bite marks on marine mammal remains from the late Miocene of Peru. Palaeogeography, Palaeoclimatology, Palaeoecology 469:84-91
• R. Esperante, L. Brand, K. E. Nick, O. Poma, and M. Urbina. 2008. Exceptional occurrence of fossil baleen in shallow marine sediments of the Neogene Pisco Formation, Southern Peru. Palaeogeography, Palaeoclimatology, Palaeoecology 257:344-360
• A. Gioncada, A. Collareta, K. Gariboldi, O. Lambert, C. Di Clema, E. Bonaccorsi, M. Urbina and G. Bianucci. 2016. Inside baleen: Exceptional microstructure preservation in a late Miocene whale skeleton from Peru. Geology
• C. S. Gutstein, M. A. Cozzuol, A. O. Vargas, M. E. Suarez, C. L. Schultz and D. Rubilar-Rogers. 2009. Patterns of skull variation of Brachydelphis (Cetacea, Odontoceti) from the Neogene of the Southeastern Pacific. Journal of Mammalogy 90(2):504-519
• O. Lambert, G. Bianucci, M. Urbina and J. H. Geisler. 2017. A new inioid (Cetacea, Odontoceti, Delphinida) from the Miocene of Peru and the origin of modern dolphin and porpoise families. Zoological Journal of the Linnean Society 179:919-946
• O. Lambert, A. Collareta, W. Landini, K. Post, B. Ramanssamy, C. Di Celma, M. Urbina and G. Bianucci. 2015. No deep diving: evidence of predation on epipelagic fish for a stem beaked whale from the Late Miocene of Peru. Proceedings of the Royal Society B 282:20151530
• O. Lambert, G. Bianucci, K. Post, C. de Muizon, R. Salas-Gismondi, M. Urbina, and J. Reumer. 2010. The giant bite of a new raptorial sperm whale from the Miocene epoch of Peru. Nature 466:105-108
• J. Machare, T. DeVries, and E. Fourtanier. 1988. Oligo-Miocene transgression along the Pacific margin of South America: new paleontological and geological evidence from the Pisco basin (Peru). Géodyynamique 3(1-2):25-37
• R. Marocco and C. de Muizon. 1988. Los vertebrados del Neogeno de La Costa Sur del Perú: Ambiente sedimentario y condiciones de fosilización. Bulletin de l'Institut Frances d'Etudes Andines 17(2):105-117
• C. de Muizon. 1988. Les vertebres fossiles de la Formation Pisco (Perou). Troisieme partie: Les Odontocetes (Cetacea, Mammalia) du Miocene. . Editions Recherche sur les Civilisations (78)1-244
• C. de Muizon and D. P. Domning. 1985. The first records of fossil sirenians in the southeastern Pacific Ocean. Bulletin du Museum National d'Histoire Naturelle. Section C: Sciences de la Terre: Paleontologie, Geologie, Mineralogie, Paris : Museum National d'Histoire Naturelle 7(3):189-213
• C. de Muizon. 1983. Pliopontos littoralis un nouveau Platanistidae Cetacea du Pliocene de la cote peruvienne. Comptes Rendus de l'Academie des Sciences Paris Serie II (296)1101-1104
• C. de Muizon. 1978. Arctocephalus (Hydrarctos) lomasiensis, subgen. nov. et nov sp., un nouvel Otariidae du Mio-Pliocene de Sacaco. Bulletin de l'Institute Francais d'Etudes Andines 7(3-4):169-189
• M. Urbina and M. Stucchi. 2005. Los cormoranes (Aves: Phalacrocoracidae) del Mio-Plioceno de la Formacion Pisco, Peru. Boletin de la Sociedad Geologica del Peru 99:41-49
• R. M. Varas Malca and A. Valenzuela Toro. 2011. A basal monachine seal from the middle Miocene of the Pisco Formation, Peru. Ameghiniana 48(4):R216-R217
• T. J. DeVries. 2008. Pliocene and Pleistocene Fissurella Bruguiére, 1789 (Gastropoda: Fissurellidae) from Southern Peru. The Veliger 50(2):129-148
• T. J. DeVries. 2007. Cenozoic Turritellidae (Gastropoda) from southern Peru. Journal of Paleontology 81(2):331-351
• T. J. DeVries, L. T. Groves, and M. Urbina. 2006. A new early Miocene Muracypraea Woodring, 1957 (Gastropoda: Cypraeidae) from the Pisco Basin of southern Peru. The Nautilus 120(3):101-105
• T. J. DeVries. 2003. Acanthina Fischer von Waldheim, 1807 (Gastropoda: Muricidae), an ocenebrine genus endemic to South America. The Veliger 46(4):332-350
• T. J. DeVries. 1997. Neogene Ficus (Mesogastropoda: Ficidae) from the Pisco Basin (Peru). Boletín de la Sociedad Geológica de Perú 86:11-18