''Spheniscus muizoni'' is an extinct

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

of banded penguins that lived during the early Late Miocene in what is now

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the souther ...

. 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 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 Middle Miocene up to the Early Pleis ...

of the

Pisco Basin Pisco Basin ( es, Cuenca de Pisco) is a sedimentary basin extending over in southwestern Peru.Solís Mundaca, 2018, p.1 The basin has a thick sedimentary fill, which is about half the thickness of more northern foreland basins in Peru. The old ...

, southwestern Peru.

Discovery and naming

Fossils of ''Spheniscus muizoni'' were found by French paleontologist Christian de Muizon in sediments belonging to the Pisco Formation at the locality Cerro la Bruja in the middle of the Pisco Basin. The material is owned by the

Muséum National d'Histoire Naturelle The French National Museum of Natural History, known in French as the ' (abbreviation MNHN), is the national natural history museum of France and a ' of higher education part of Sorbonne Universities. The main museum, with four galleries, is loca ...

in Paris.Göhlich, 2007, p.286 The species epithet was chosen in honour of De Muizon, who has greatly contributed to the faunal descriptions of the Pisco Formation and other areas in Peru.

Description

The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of seve ...

material consists of a partial postcranial skeleton, subcomplete left and right

coracoid A coracoid (from Greek κόραξ, ''koraks'', raven) is a paired bone which is part of the shoulder assembly in all vertebrates except therian mammals (marsupials and placentals). In therian mammals (including humans), a coracoid process is pre ...

, subcomplete right

scapula The scapula (plural scapulae or scapulas), also known as the shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones, the scapulae are paired, with each scapula on eithe ...

, a subcomplete left and right

humerus The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

, the left complete

ulna The ulna (''pl''. ulnae or ulnas) is a long bone found in the forearm that stretches from the elbow to the smallest finger, and when in anatomical position, is found on the medial side of the forearm. That is, the ulna is on the same side of t ...

, proximal and distal end of the right

femur The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates wit ...

, the complete right and proximal end of the left

tibiotarsus The tibiotarsus is the large bone between the femur and the tarsometatarsus in the leg of a bird. It is the fusion of the proximal part of the tarsus with the tibia. A similar structure also occurred in the Mesozoic Heterodontosauridae. These sm ...

, the proximal end of the left

fibula The fibula or calf bone is a human leg, leg bone on the Lateral (anatomy), lateral side of the tibia, to which it is connected above and below. It is the smaller of the two bones and, in proportion to its length, the most slender of all the long ...

, the right complete

tarsometatarsus The tarsometatarsus is a bone that is only found in the lower leg of birds and some non-avian dinosaurs. It is formed from the fusion of several bones found in other types of animals, and homologous to the mammalian tarsus (ankle bones) and meta ...

, the cranial portion of the

sternum The sternum or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major blood vessels from injury. ...

with articular sulcus for coracoid and fragment of the craniolateral process, two fragmentary

thoracic vertebra In vertebrates, thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In humans, there are twelve thoracic vertebrae and they are intermediate in size between the cervica ...

e from the caudal region, seven caudal vertebrae and a fragmentary

synsacrum The synsacrum is a skeletal structure of birds and other dinosaurs, in which the sacrum is extended by incorporation of additional fused or partially fused caudal or lumbar vertebrae and it can only be seen in birds. Some posterior thoracic vert ...

.Göhlich, 2007, p.287

Paratype In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype nor a syntype). O ...

fossils of the species consist of isolated bones; a distal fragmentary half of left coracoid, the right subcomplete coracoid, a left complete ulna, left complete radius, right complete carpometacarpus, the distal end of a right femur, the cranial end of

pygostyle Pygostyle describes a skeletal condition in which the final few caudal vertebrae are fused into a single ossification, supporting the tail feathers and musculature. In modern birds, the rectrices attach to these. The pygostyle is the main compo ...

and a rib fragment without ends. The body mass of the penguin species has been estimated to , making it smaller than the

Magellanic penguin The Magellanic penguin (''Spheniscus magellanicus'') is a South American penguin, breeding in coastal Patagonia, including Argentina, Chile, and the Falkland Islands, with some migrating to Brazil and Uruguay, where they are occasionally see ...

at and distinctly smaller than the

Humboldt penguin The Humboldt penguin (''Spheniscus humboldti'') is a medium-sized penguin. It resides in South America, its range mainly contains most of coastal Peru. Its nearest relatives are the African penguin, the Magellanic penguin and the Galápagos p ...

, but larger than the

Galapagos penguin The Galápagos penguin (''Spheniscus mendiculus'') is a penguin Endemism, endemic to the Galápagos Islands, Ecuador. It is the only penguin found north of the equator. Most inhabit Fernandina Island and the west coast of Isabela Island (Galáp ...

, which has a body mass of . Detailed comparisons with extant and fossil species of ''Spheniscus'' suggest that the available postcranial bones of ''S. muizoni'' morphologically correspond best with those of ''

Spheniscus urbinai The banded penguins are penguins that belong to the genus ''Spheniscus''. There are four living species, all with similar banded plumage patterns. They are sometimes also known as "jack-ass penguins" due to their loud locator calls sounding simil ...

'' from the same formation, aside from that the latter is distinctly larger. Based on the morphological similarity of ''Spheniscus muizoni'' ''S. urbinai'' and their stratigraphical succession within the Pisco Formation, it can be supposed that the first gave directly rise at least to the latter.''S. muizoni'' is the only known penguin species from the Cerro la Bruja locality and is unknown from any older or younger deposit in or outside the Pisco Formation. ''Spheniscus muizoni'' is not only the oldest penguin species in the Pisco Formation, but also representing the stratigraphically oldest record for the extant genus ''Spheniscus'' in general.Göhlich, 2007, p.296

Paleoecology

Spheniscus muizoni - fossils 2 - Pisco Formation, Peru

The Pisco Formation has a long age range, from about 15 Ma ( Middle Miocene;

Colloncuran The Colloncuran ( es, Colloncurense) age is a period of geologic time (15.5–13.8 Ma) within the Middle Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Friasian and precedes ...

) to approximately 2 Ma ( Early Pleistocene;

Uquian The Uquian age is a period of geologic time (3.0–1.5 Ma) within the Pliocene and Pleistocene epochs of the Neogene used more specifically with South American Land Mammal Ages. It follows the Montehermosan and precedes the Ensenadan The Ensen ...

in the SALMA classification). The formation at the Cerro la Bruja paleontological site is characterized by

tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock ...

aceous

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates ...

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, ...

s and diatomaceous siltstones with a basal conglomerate.

Hardground Carbonate hardgrounds are surfaces of synsedimentarily cemented carbonate layers that have been exposed on the seafloor (Wilson and Palmer, 1992). A hardground is essentially, then, a lithified seafloor. Ancient hardgrounds are found in limestone ...

s are present at the location. The

depositional environment In geology, depositional environment or sedimentary environment describes the combination of physical, chemical, and biological processes associated with the deposition of a particular type of sediment and, therefore, the rock types that will b ...

of the Pisco Formation at this locality is interpreted as a shallow to deeper shelf setting.Cerro la Bruja
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cre ...

.org The fossil record indicates a faunal change of ''Spheniscus'' species within the stratigraphically older sequence of the Pisco Formation. While '' Spheniscus megaramphus'' is found at the Late Miocene Montemar Norte location, and ''

Spheniscus humboldti The Humboldt penguin (''Spheniscus humboldti'') is a medium-sized penguin. It resides in South America, its range mainly contains most of coastal Peru. Its nearest relatives are the African penguin, the Magellanic penguin and the Galápagos peng ...

'' is recovered from the Early Pleistocene Yauca locality,Stucchi, 2007, p.370 ''S. muizoni'' occurs exclusively in the oldest deposits (latest middle/earliest late Miocene, 13–11 Ma;

Serravallian The Serravallian is, in the geologic timescale, an age or a stage in the middle Miocene Epoch/ Series, which spans the time between 13.82 Ma and 11.63 Ma (million years ago). The Serravallian follows the Langhian and is followed by the Tort ...

, or

Laventan The Laventan ( es, Laventense) age is a period of geologic time (13.8 to 11.8 Ma) within the Middle Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Colloncuran and precedes the ...

SALMA) and was probably replaced by the persistent ''S. urbinai'', which is found in strata dating from the Late Miocene to the Early Pliocene (9 to 3.5 Ma).Göhlich, 2007, p.297Stucchi, 2007, p.369 The formation in other, mostly younger, locations has provided an exceptionally rich faunal assemblage of toothed whales, baleen whales, dolphins, seals, swimming sloths (''

Thalassocnus ''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. lit ...

''),De Muizon et al., 2004 and other birds (among which other ''Spheniscus'' penguins). At Cerro la Bruja, fossils of rays ('' Myliobatis sp.''), sharks (among which

megalodon Megalodon (''Otodus megalodon''), meaning "big tooth", is an extinct species of mackerel shark that lived approximately 23 to 3.6 million years ago (Mya), from the Early Miocene to the Pliocene epochs. It was formerly thought to be a me ...

), other birds (''

Pelagornis ''Pelagornis'' is a widespread genus of prehistoric pseudotooth birds. These were probably rather close relatives of either pelicans and storks, or of waterfowl, and are here placed in the order Odontopterygiformes to account for this uncertai ...

''), bony fish (

Triglidae Triglidae, commonly known as gurnards or sea robins, are a family of bottom-feeding scorpaeniform ray-finned fish. The gurnards are distributed in temperate and tropical seas worldwide. Taxonomy Triglidae was first described as a family in 18 ...

Xiphiidae Swordfish (''Xiphias gladius''), also known as broadbills in some countries, are large, highly migratory predatory fish characterized by a long, flat, pointed bill. They are a popular sport fish of the billfish category, though elusive. Swordfi ...

and

Alosinae The Alosinae, or the shads,Alosinae

),Báez Gómez, 2006, p.66 and the

cetacean Cetacea (; , ) is an infraorder of aquatic mammals that includes whales, dolphins, and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively carnivorous diet. They propel them ...

s '' Acrophyseter robustus'',Lambert et al., 2008 ''

Atocetus iquensis ''Atocetus'' is an extinct genus of Pontoporiidae, pontoporiid dolphin found in Miocene-age marine deposits in Peru and California. Description The type species, ''Atocetus iquensis'', is known from Serravallian-age strata of the Pisco Format ...

'',De Muizon, 1988, p.131 '' Brachydelphis mazeasi'',De Muizon, 1988, p.82 and '' Belonodelphis peruanus'' were found.De Muizon, 1988, p.192 In all extant ''Spheniscus'' species

pelagic The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or w ...

school fish (mostly

anchovies An anchovy is a small, common forage fish of the family Engraulidae. Most species are found in marine waters, but several will enter brackish water, and some in South America are restricted to fresh water. More than 140 species are placed in 1 ...

) is the dominant prey;

cephalopod A cephalopod is any member of the molluscan class Cephalopoda ( Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, ...

s and

crustacea Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean gro ...

ns are subordinate. Because the skull of ''Spheniscus muizoni'' is lacking, no information is available on the shape of the bill, which varies at least in some extant penguin genera and their preferred diet.

References

Bibliography

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* ;Other fauna * * * * * {{Taxonbar, from=Q6133144 †muizoni Extinct penguins Miocene birds of South America Serravallian life Laventan Neogene Peru Fossils of Peru Pisco Formation Fossil taxa described in 2007