Paraptenodytes robustus is the type species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of the penguin

Penguin

Penguins are a group of aquatic, flightless birds living almost exclusively in the southern hemisphere, especially in Antarctica. Highly adapted for life in the water, penguins have countershaded dark and white plumage, and their wings have become flippers...

 genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Palaeospheniscus, which is known from fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

s. It was medium-sized, an estimated 70–80 cm long in life (similar to a Magellanic Penguin

Magellanic Penguin

The Magellanic Penguin, Spheniscus magellanicus, is a South American penguin, breeding in coastal Argentina, Chile and the Falkland Islands, with some migrating to Brazil where they are occasionally seen as far north as Rio de Janeiro. It is the most numerous of the Spheniscus penguins. Its nearest...

).

The fossils of this species are known from several dozen bones, found in Early Miocene

Miocene

The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...

 rocks of the Patagonian Molasse Formation. Documented locations are near La Cueva

La Cueva

La Cueva is a town in the Sánchez Ramírez province of the Dominican Republic.- Sources :* – World-Gazetteer.com...

, Trelew

Trelew

-References:La Pasión según Trelew, Espejo de la Argentina, 1997, Editorial Planeta Argentina S.A.I.C.; Third Edition: April 2000, Buenos Aires, ISBN 950-742-859-3-External links:* * * *...

 in Chubut Province

Chubut Province

Chubut a province in the southern part of Argentina situated between the 42nd parallel south and the 46th parallel south , the Andes range separating Argentina from Chile, and the Atlantic ocean...

, and Puerto San Julián

Puerto San Julián

Puerto San Julián, also known historically as Port St Julian, is a natural harbour in Patagonia in the Santa Cruz Province of Argentina located at . In the days of sailing ships it formed a stopping point, south of Puerto Deseado...

 in Santa Cruz Province

Santa Cruz Province (Argentina)

Santa Cruz is a province of Argentina, located in the southern part of the country, in Patagonia. It borders Chubut province to the north, and Chile to the west and south. To the east is the Atlantic Ocean...

, Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

. Most remains are only tentatively assigned to this species, however, and the tarsometatarsus

Tarsometatarsus

The tarsometatarsus is a bone that is found in the lower leg of certain tetrapods, namely birds.It is formed from the fusion of several bones found in other types of animals, and homologous to the mammalian tarsal and metatarsal bones...

 formerly referred to as Treleudytes crassus may belong to a completely different species. On the other hand, Paraptenodytes brodkorbi

Paraptenodytes brodkorbi

Paraptenodytes brodkorbi is a proposed, but possibly invalid, species of extinct penguin. The bird was probably about the size of an King Penguin....

is probably synonymous with P. robustus.