The etymology of the name Plateosaurus is not entirely clear.
Moser pointed out that the original description contains no information, and various authors have offered differing interpretations.
German geologist Hanns Bruno Geinitz in 1846 gave "(πλατυς, breit)" [English: broad] In the same year, Agassiz offered Ancient Greek πλατη (platê – "paddle", "rudder"; Agassiz translates this as Latin pala = "spade") and σαυρος (sauros – "lizard").
Agassiz consequently renamed the genus Platysaurus, probably from Greek πλατυς (platys – "broad, flat, broad-shouldered"), creating an invalid junior synonym.
Later authors often referred to this derivation, and the secondary meaning "flat" of πλατυς, so that Plateosaurus is often translated as "flat lizard".
Often, claims were made that πλατυς is supposed to have been intended as a reference to flat bones, for example the laterally flattened teeth of Plateosaurus, but the teeth and other flat bones such as the pubic bones and some skull elements were unknown at the time of description.

In 1855, von Meyer published a detailed description of Plateosaurus with illustrations, but again gave no details on the etymology.
He repeatedly referred to its gigantic size ("Riesensaurus" = giant lizard) and massive limbs ("schwerfüssig"), comparing Plateosaurus to large modern land mammals, but did not describe any important features that fit the terms "flat" or "shaped like an oar."

In addition to his formal scientific descriptions, von Meyer also gave a public lecture about fossil reptiles in 1851 that included a short mention of Plateosaurus.
That talk and a later one on fossil mammals were turned into a general audience book published in 1852, entitled Über die Reptilien und Säugethiere der verschiedenen Zeiten der Erde [On the Reptiles and Mammals from the Different Time Periods of the Earth].
In the German text (page 44), von Meyer briefly described Plateosaurus and mentioned that it had "breite, starke Gliedmaassenknochen," which translates as "broad, strong limb bones."
Because his original description of Plateosaurus in 1837 stressed the similarity of its large limb bones to those of Megalosaurus and Iguanodon, a meaning "broad lizard" for the name Plateosaurus to refer in particular to its robust limb bones would seem plausible.
The etymology of the name Plateosaurus is not entirely clear. Moser pointed out that the original description contains no information, and various authors have offered differing interpretations. German geologist Hanns Bruno Geinitz in 1846 gave "(πλατυς, breit)" [English: broad] In the same year, Agassiz offered Ancient Greek πλατη (platê – "paddle", "rudder"; Agassiz translates this as Latin pala = "spade") and σαυρος (sauros – "lizard"). Agassiz consequently renamed the genus Platysaurus, probably from Greek πλατυς (platys – "broad, flat, broad-shouldered"), creating an invalid junior synonym. Later authors often referred to this derivation, and the secondary meaning "flat" of πλατυς, so that Plateosaurus is often translated as "flat lizard". Often, claims were made that πλατυς is supposed to have been intended as a reference to flat bones, for example the laterally flattened teeth of Plateosaurus, but the teeth and other flat bones such as the pubic bones and some skull elements were unknown at the time of description.
In 1855, von Meyer published a detailed description of Plateosaurus with illustrations, but again gave no details on the etymology. He repeatedly referred to its gigantic size ("Riesensaurus" = giant lizard) and massive limbs ("schwerfüssig"), comparing Plateosaurus to large modern land mammals, but did not describe any important features that fit the terms "flat" or "shaped like an oar."
In addition to his formal scientific descriptions, von Meyer also gave a public lecture about fossil reptiles in 1851 that included a short mention of Plateosaurus. That talk and a later one on fossil mammals were turned into a general audience book published in 1852, entitled Über die Reptilien und Säugethiere der verschiedenen Zeiten der Erde [On the Reptiles and Mammals from the Different Time Periods of the Earth]. In the German text (page 44), von Meyer briefly described Plateosaurus and mentioned that it had "breite, starke Gliedmaassenknochen," which translates as "broad, strong limb bones." Because his original description of Plateosaurus in 1837 stressed the similarity of its large limb bones to those of Megalosaurus and Iguanodon, a meaning "broad lizard" for the name Plateosaurus to refer in particular to its robust limb bones would seem plausible.
Plateosaurus