The Santa Rosa local fauna consists of the animals found in the

Paleogene The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...

fossil site of Santa Rosa in eastern Peru. The age of the Santa Rosa fauna is difficult to determine, but may be

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

( Mustersan) or

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

(

Deseadan The Deseadan () age is a period of geologic time (29.0–21.0 Ma) within the Oligocene epoch of the Paleogene to the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification of South America. It follows the Tingu ...

History and context

Few fossils have been found in the vast rainforests of the Amazon Basin, and Santa Rosa was the first

fauna to be discovered in the region. The Santa Rosa local fauna was discovered in July 1995, and the discovery was briefly reported in 1996. In 1998, further fossil samples were taken at the site. Though not all of the material had been sorted, a report on the fauna was published in 2004 in a volume edited by Kenneth Campbell of the

Natural History Museum of Los Angeles County Nature is an inherent character or constitution, particularly of the ecosphere or the universe as a whole. In this general sense nature refers to the laws, elements and phenomena of the physical world, including life. Although humans are par ...

. The publication was reviewed favorably by Bruce MacFadden in the '' Journal of Mammalian Evolution''.

Location and geology

The Santa Rosa fossil site is located in eastern Peru's Atalaya Province. It is about north of the town of Breu, south of the Brazilian border, and north of a small village named Santa Rosa. It is on the left (west) bank of the Río Yurúa at an altitude of . The fossils were found in coarse

fluvial A river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it ru ...

deposits that form thin

lenses A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements''), ...

along the bank of the river. There is a number of similar rock units—so-called "red beds"—in the Tertiary deposits of western Amazonia, including eastern Peru, and it is difficult to assign the isolated Santa Rosa outcrop to any of them. However, Campbell and colleagues suggested on the basis of the stage of evolution of the rodents and marsupials found that Santa Rosa dates to the Mustersan South American Land Mammal Age, which is part of the

. This would make it likely that it is part of the Yahuarango Formation, which may be

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

to Eocene in age. On the other hand, they suggested that Santa Rosa could be younger, perhaps

, and could fall either into a continuation of the Yahuarango Formation or into the younger Chambira Formation. Indeed, María Vucetich noted in 2010 that some of the Santa Rosa rodents are similar to

(Oligocene) forms, and the notoungulates also suggest a younger age.

Fauna

The Santa Rosa local fauna contains mammals, other vertebrates, and some crabs and charophyte algae. Not all of the fossils found at Santa Rosa have been described in detail yet, and not all the material retrieved has been sorted. Full descriptions have been published of the Santa Rosa marsupials, rodents, and notoungulates. Two single teeth that may represent a bat and a gondwanathere have also been described. Other fossils found at Santa Rosa have not been described in detail. There are some

xenarthra Xenarthra (; from Ancient Greek ξένος, xénos, "foreign, alien" + ἄρθρον, árthron, "joint") is a superorder and major clade of placental mammals native to the Americas. There are 31 living species: the anteaters, tree sloths, and ...

ns, numerous fish representing at least five

families Family (from ) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictability, structure, and safety as ...

, many

crocodilia Crocodilia () is an order of semiaquatic, predatory reptiles that are known as crocodilians. They first appeared during the Late Cretaceous and are the closest living relatives of birds. Crocodilians are a type of crocodylomorph pseudosuchia ...

ns, some turtles, possibly some lizards, and a few fossils of amphibians and birds. Crab claws found at the site probably represent the family Pseudothelphusiidae. The marsupial fauna of Santa Rosa is known from 79 isolated teeth, which represent eleven species. The fauna is taxonomically diverse, comprising members of the orders Microbiotheria (represented among living marsupials only by the monito del monte), Paucituberculata (shrew opossums),

Didelphimorphia Opossums () are members of the marsupial order Didelphimorphia () endemic to the Americas. The largest order of marsupials in the Western Hemisphere, it comprises 126 species in 18 genera. Opossums originated in South America and entered North A ...

(opossums), and the extinct

Sparassodonta Sparassodonta (from Ancient Greek, Greek to tear, rend; and , gen.

, ' The comma is a punctuation mark that appears in several variants in different languages. Some typefaces render it as a small line, slightly curved or straight, but inclined from the vertical; others give it the appearance of a miniature fille ...

tooth) is an extinct order (biology), order of carnivore, carnivorous metatherian mammals native to South America, related to modern marsupials. They were once cons ...

and Polydolopimorphia. Two genera, '' Wirunodon'' and '' Kiruwamaq'', cannot be assigned to any existing marsupial order. The largest species found, the sparassodont '' Patene campbelli'', was cat-sized, but most species were the size of a mouse. Most Santa Rosa marsupials are thought to have been

frugivore A frugivore ( ) is an animal that thrives mostly on raw fruits or succulent fruit-like produce of plants such as roots, shoots, nuts and seeds. Approximately 20% of mammalian herbivores eat fruit. Frugivores are highly dependent on the abundance ...

s and/or

insectivore file:Common brown robberfly with prey.jpg, A Asilidae, robber fly eating a hoverfly An insectivore is a carnivore, carnivorous animal or plant which eats insects. An alternative term is entomophage, which can also refer to the Entomophagy ...

s; on the other hand, ''Patene'' was a carnivore. The most common species found, the polydolopimorphian '' Wamradolops tsulludon'', shows features that suggest it was adapted for breaking down hard food items such as seeds or bark. Hundreds of rodent fossils have been found at Santa Rosa, many of which cannot be identified precisely. These rodents are referable to the

caviomorph Caviomorpha is the rodent parvorder that unites all New World hystricognaths. It is supported by both fossil and molecular evidence. The Caviomorpha was for a time considered to be a separate order outside the Rodentia, but is now accepted as ...

group of rodents, which is unique to the Americas, and includes at least eleven species classified in the families Erethizontidae (New World porcupines),

Echimyidae Echimyidae is the family of neotropical spiny rats and their fossil relatives. This is the most species-rich family of hystricognath rodents. It is probably also the most ecologically diverse, with members ranging from fully arboreal to terr ...

(spiny rats), and Agoutidae (agoutis). All Santa Rosa rodents share a common morphological pattern of the teeth, suggestive of a basal place in the caviomorph radiation. The extinct "ungulate" order

Notoungulata Notoungulata is an extinct order of ungulates that inhabited South America from the early Paleocene to the end of the Pleistocene, living from approximately 61 million to 11,000 years ago. Notoungulates were morphologically diverse, with forms re ...

is represented by a few fossils only. Four isolated teeth may represent the same species, a sheep-sized member of the suborder Toxodontia. A single, very small tooth may belong to a member of the toxodont family Notohippidae. A jaw fragment is referable to the family Interatheriidae (suborder Typotheria). A single damaged lower molar documents the possible presence of a bat at Santa Rosa. The specimen is fragmentary enough that it cannot be identified positively as a bat. It shows some features that suggest a relationship with the living bat family Noctilionidae (bulldog bats). When published, this specimen represented the oldest known South American bat, but an older bat was described from Argentina in 2005. Another isolated tooth, LACM 149371, cannot be aligned securely with any mammalian group. Francisco Goin and colleagues, who described this specimen, tentatively suggested that it represents an upper molar of a member of the family Ferugliotheriidae, part of the ancient and enigmatic group Gondwanatheria. If this identification is correct, it would be among the youngest known gondwanatheres.

Faunal list

The following species of mammals have been recorded at Santa Rosa: * Order

Primate Primates is an order (biology), order of mammals, which is further divided into the Strepsirrhini, strepsirrhines, which include lemurs, galagos, and Lorisidae, lorisids; and the Haplorhini, haplorhines, which include Tarsiiformes, tarsiers a ...

s ** Suborder

Anthropoidea The simians, anthropoids, or higher primates are an infraorder (Simiiformes ) of primates containing all animals traditionally called monkeys and apes. More precisely, they consist of the parvorders Platyrrhini (New World monkeys) and Catar ...

*** Family indeterminate **** Genus '' Perupithecus'' ***** '' Perupithecus ucayaliensis'' * Order indeterminate ** Possibly family Ferugliotheriidae ( LACM 149371) * Order

(opossums) **

cf. The abbreviation cf. (short for either Latin or , both meaning 'compare') is generally used in writing to refer the reader to other material to make a comparison with the topic being discussed. However some sources offer differing or even contr ...

Family

Herpetotheriidae Herpetotheriidae is an extinct family of metatherians, closely related to marsupials. Species of this family are generally reconstructed as terrestrial, and are considered morphologically similar to modern opossums. They are suggested to have b ...

*** Genus '' Rumiodon'' **** '' Rumiodon inti'' **** ''Rumiodon'' sp. * Order

Sparassodonta Sparassodonta (from Ancient Greek, Greek to tear, rend; and , gen.

tooth) is an extinct order (biology), order of carnivore, carnivorous metatherian mammals native to South America, related to modern marsupials. They were once cons ...

** Family Hathliacynidae *** Genus '' Patene'' **** '' Patene campbelli'' * Order Polydolopimorphia ** Family Prepidolopidae *** Genus '' Incadolops'' **** '' Incadolops ucayali'' ** Family indeterminate *** Genus '' Hondonadia'' **** '' Hondonadia pittmanae'' *** Genus '' Wamradolops'' **** '' Wamradolops tsullodon'' * Order Paucituberculata (shrew opossums) ** Family Caenolestidae *** Genus '' Perulestes'' **** '' Perulestes cardichi'' **** '' Perulestes fraileyi'' ** cf. Family Palaeothentidae *** Genus '' Sasawatsu'' **** '' Sasawatsu mahaynaq'' * Order Microbiotheria (monito del monte) ** Family Microbiotheriidae *** Genus '' Kirutherium'' **** '' Kirutherium paititiensis'' * Marsupialia, order and family indeterminate ** Genus '' Kiruwamaq'' *** '' Kiruwamaq chisu'' ** Genus '' Wirunodon'' *** '' Wirunodon chanku'' * Order

** Suborder Toxodontia *** Family, genus and species indeterminate (perhaps more than one species) *** cf. Family Notohippidae **** Genus and species indeterminate ** Suborder Typotheria *** Family Interatheriidae **** Genus and species indeterminate * Order

Rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

ia (rodents) ** Family Erethizontidae (New World porcupines) *** Genus '' Eopululo'' **** '' Eopululo wigmorei'' ** Family Agoutidae (agoutis) *** Genus '' Eobrasinamys'' **** '' Eobrasinamys riverai'' **** '' Eobranisamys romeropittmanae'' *** Genus '' Eoincamys'' **** '' Eoincamys ameghinoi'' **** '' Eoincamys pascuali'' *** Genus '' Eopicure'' **** '' Eopicure kraglievichi'' *** Genus and species indeterminate A *** Genus and species indeterminate B *** Genus and species indeterminate C ** Family

(spiny rats) *** Genus '' Eodelphomys'' **** '' Eodelphomys almeidacomposi'' *** Genus '' Eoespina'' **** '' Eoespina woodi'' *** Genus '' Eosachacui'' **** '' Eosachacui lavocati'' *** Genus '' Eosallamys'' **** '' Eosallamys paulacoutoi'' **** '' Eosallamys simpsoni'' *** Genus and species indeterminate A *** Genus and species indeterminate B *** Genus and species indeterminate C * Order

Chiroptera Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

(bats) ** Family, genus, and species indeterminate

References

Bibliography

* * * * * * * * * * * * * *{{cite book , last1 = Woods , first1 = C.A. , last2 = Kilpatrick , first2 = C.W. , year = 2005 , chapter-url = http://www.bucknell.edu/msw3 , publisher = Johns Hopkins University Press , location = Baltimore, Maryland , isbn = 978-0-8018-8221-0 , pages = 1538–1600 , chapter = Infraorder Hystricognathi , title = Mammal Species of the World: A Taxonomic and Geographic Reference , edition = 3rd , editor1-last = Wilson , editor1-first = D.E. , editor2-last = Reeder , editor2-first = D.M Cenozoic paleontological sites of South America Eocene paleontological sites Oligocene paleontological sites Paleogene Peru Geology of Peru Paleontology in Peru Amazonas Region Prehistoric fauna by locality Cenozoic paleobiotas