Blubber is a thick layer of vascularized adipose tissue under the skin of all cetaceans, pinnipeds, penguins, and sirenians.
Didelphodon is a genus of stagodont metatherians from the Late Cretaceous of North America.
Megatheriidae is a family of extinct ground sloths that lived from approximately 23 mya—11,000 years ago.
Placodus was a genus of marine reptiles belonging to the order Placodontia, which swam in the shallow seas of the middle Triassic period. Fossils of Placodus have been found in Central Europe and China.
Odobenocetops is an extinct genus of small toothed whale known from Peru and Chile. Its fossils are found in Neogene-aged marine strata dating from the Tortonian to the Zanclean. It had two tusks, and, in some fossils, one tusk was longer than the other.
Thalassocnus is an extinct genus of semiaquatic ground sloths from the Miocene and Pliocene of the Pacific South American coast. It is monotypic within the subfamily Thalassocninae. The five species—T. antiquus, T. natans, T. littoralis, T. carolomartini, and T. yuacensis—represent a chronospecies, a population gradually adapting to marine life in one direct lineage. They are the only known aquatic sloths, but they may have also been adapted to a terrestrial lifestyle. They have been found in the Pisco Formation of Peru, the Tafna Formation of Argentina, and the Bahía Inglesa, Coquimbo, and Horcón formations of Chile. Thalassocninae has been placed in both the families Megatheriidae and Nothrotheriidae.
Pachyostosis is a non-pathological condition in vertebrate animals in which the bones experience a thickening, generally caused by extra layers of lamellar bone. It often occurs together with bone densification (osteosclerosis), reducing inner cavities. This joint occurrence is called pachyosteosclerosis. However, especially in the older literature, "pachyostosis" is often used loosely, referring to all osseous specializations characterized by an increase in bone compactness and/or volume. It occurs in both terrestrial and, especially, aquatic or semi-aquatic vertebrates.
The Friasian age is a period of geologic time within the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification of South America. It follows the Santacrucian and precedes the Colloncuran age.
Piscobalaena is an extinct genus of cetaceans, which lived from the Middle to Late Miocene epochs in Peru and Florida. Its fossils have been found in the Pisco Formation of Peru and the Bone Valley Formation of Florida. At least some individuals of this diminutive whale were preyed on by the shark C. megalodon.
Nothrotheriidae is a family of extinct ground sloths that lived from approximately 17.5 mya—10,000 years ago, existing for approximately 17.49 million years. Previously placed within the tribe Nothrotheriini or subfamily Nothrotheriinae within Megatheriidae, they are now usually placed in their own family, Nothrotheriidae. Nothrotheriids appeared in the Burdigalian, some 19.8 million years ago, in South America. The group includes the comparatively slightly built Nothrotheriops, which reached a length of about 2.75 metres (9.0 ft). While nothrotheriids were small compared to some of their megatheriid relatives, their claws provided an effective defense against predators, like those of larger anteaters today.
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 Early Pleistocene, roughly from 15 to 2 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.
Pachyosteosclerosis is a combination of thickening (pachyostosis) and densification (osteosclerosis) of bones. It makes bones more heavy, but also more fragile. The condition often occurs in aquatic vertebrates, especially those living in shallow waters, creating ballast as an adaptation for maintaining neutral buoyancy and horizontal trim. It is in no way pathological. To resist bend, it frequently is found especially in ventral bones, whereas concentration near the lungs helps in maintaining trim. Examples of animals showing pachyosteosclerosis are seacows, the extinct Plesiosauria and Mesosauria and extinct aquatic sloths.
Homiphoca is an extinct genus of earless seals from the Pliocene of South Africa.
Tiucetus is an extinct genus of cetotheriid baleen whale known from the Late Miocene Pisco Formation of Peru.
Brachydelphis is a genus of pontoporiid known from the Late Miocene Pisco Formation of Peru and the Bahía Inglesa Formation of Chile.
Balaenoptera siberi is an extinct species of baleen whale from the Late Miocene, described by Pilleri and Pilleri in 1989, based on fossils found in the Pisco Formation of the Pisco Basin in southwestern Peru.
Macrosqualodelphis is an extinct genus of river dolphins from the Early Miocene (Burdigalian) Chilcatay Formation of the Pisco Basin, Peru. The type species is M. ukupachai.
Spheniscus muizoni is an extinct species of banded penguins that lived during the early Late Miocene in what is now Peru, South America. The species, the earliest member of the extant genus, was described in 2007 by Ursula B. Göhlich based on fossils found in the fossiliferous Pisco Formation of the Pisco Basin, southwestern Peru.
Peregocetus is a genus of early whale that lived in what is now Peru during the Middle Eocene epoch. Its fossil was uncovered in 2011 in the Yumaque Formation of the Pisco Basin at Playa Media Luna by a team consisting of members from Belgium, Peru, France, Italy, and the Netherlands. Parts recovered include the jaw, front and hind legs, bits of spine, and tail. Olivier Lambert, a scientist at the Royal Belgian Institute of Natural Sciences and lead author of the study, noted that Peregocetus "fills in a crucial [knowledge] gap" about the evolution of whales and their spread.
