Fossil taxa described in 1897

Trigonostylops is an extinct genus of South American meridiungulatan ungulate, from the Late Paleocene to Late Eocene (Itaboraian to Tinguirirican in the SALMA classification) of South America (Argentina and Peru) and Antarctica (Seymour Island). It is the only member of the family Trigonostylopidae.

Notostylops ("south pillar face") is a genus of extinct South American notoungulates from Eocene Argentina. Fossils of the genus have been found in the Sarmiento, Casamayor, Andesitas Huancache and Koluel Kaike Formations. Image:Notostylopss.png|Size comparison of Notostylops murinus with a human. Image:Notostylops murinus Wikipedia Juandertal.jpg|Life reconstruction.

Didolodus is an extinct genus of mammals from Middle Eocene Argentina. It is an ungulate mammal of uncertain affinities, possibly related to Litopterna, though this is uncertain due to the lack of reliable post-cranial remains, and for now remains Meridiungulata incertae sedis. Its remains were found in the Sarmiento Formation of Patagonia.

Proborhyaena is an extinct genus of proborhyaenid sparassodont that lived during the Oligocene of South America. It is considered to be the largest of the sparassodonts.

Rhynchippus ("beaked horse") is an extinct genus of notoungulate mammals from the Late Oligocene (Deseadan in the SALMA classification) of South America. The genus was first described by Florentino Ameghino in 1897 and the type species is R. equinus, with lectotype MACN A 52–31. Fossils of Rhynchippus have been found in the Agua de la Piedra and Sarmiento Formations of Argentina, the Salla and Petaca Formations of Bolivia, the Tremembé Formation of Brazil, and the Moquegua Formation of Peru.

Eastmanosteus ("Eastman's bone") is a fossil genus of dunkleosteid placoderms. It was closely related to the giant Dunkleosteus, but differed from that genus in size, in possessing a distinctive tuberculated bone ornament, a differently shaped nuchal plate and a more zig-zagging course of the sutures of the skull roof.

Pharsophorus is an extinct genus of borhyaenoid sparassodont that inhabited South America during the Middle to Late Oligocene epoch.

species of bird (fossil)

Pleurostylodon is an extinct genus of notoungulate belonging to the family Isotemnidae. It lived during the Middle Eocene, in what is now Argentina.

Isotemnus is an extinct genus of notoungulate belonging to the family Isotemnidae. It lived from the Late Paleocene to the Middle Eocene of what is now Argentina.

Arnioceras is an extinct genus of large, evolute, discoidal ammonite from the Lower Jurassic. The shell is normally coiled so that all whorls are exposed. Sides bear strong sharp ribs that are straight until reaching the ventrolateral edge where they swing forward and fade. The rim (venter) is keeled and free of grooves.

species of bird

Propachyrucos is an extinct genus of late Oligocene hegetotheriid notoungulate. It is known from a few mandibular fragments from the Sarmiento Formation, Chubut Province, Argentina.

Archaeopithecus is an extinct genus of notoungulate, belonging to the suborder Typotheria. It lived during the Middle Eocene, in what is today Argentina.