Fossil taxa described in 1834

Basilosaurus (meaning "king lizard") is a genus of large, predatory, prehistoric archaeocete whale from the late Eocene, approximately 41.3 to 33.9 million years ago (mya). First described in 1834, it was the first archaeocete and prehistoric whale known to science. Fossils attributed to the type species B. cetoides were discovered in the southeastern United States. The generic name, meaning "king lizard", was given due to the initial misconception about the fossil material as that of a giant reptile. The animal was later found to be an early marine mammal, prompting attempts at renaming the c

Nothosaurus ('false lizard', from the Ancient Greek and ) is an extinct genus of sauropterygian reptile from the Triassic period, approximately 245–228 million years ago, with fossils being distributed throughout the former Tethys Ocean, from North Africa and Europe to China. It is the best known member of the nothosaur order.

thumb|left|Holotype skull Mystriosaurus is an extinct genus of teleosaurid crocodyliform from the Early Jurassic (Toarcian). Fossil specimens have been found in the Whitby Mudstone of England and Posidonia Shale of Germany. The only known species, M. laurillardi, exceeded in length.

thumb|left|Saurichthys curionii fossil from the Middle Triassic of [[Monte San Giorgio, Switzerland]] thumb|left|Early Triassic and [[Middle Triassic marine predators: 3. Saurichthys]]

genus of fishes

Macrodontophion (meaning "long-toothed snake") is the name given to a dubious genus of lophotrochozoan from the Early Devonian Dniester Series of Podolia, Ukraine. It was described by Adalbert Zborzewsky in 1834, but was never given a species epithet, and is considered a nomen dubium, because it is based only on fragments, such as the holotype, a shell of .

Hyotherium (meaning "pig beast", due to its resemblance to modern day pigs.) was an extinct genus of even-toed ungulates under the Hyotheriinae group (a group that also consists of Chicochoerus, Xenohyus and more) of the Suidae family. It existed during the Miocene in Europe and Perim Island, India. It was named by Von Mayer in 1834.

Belonostomus (from , 'dart' and 'mouth') is a genus of prehistoric ray-finned fish that was described by Louis Agassiz in 1844. It is a member of the order Aspidorhynchiformes, a group of fish known for their distinctive elongated rostrums.