Gresslyosaurus is an extinct genus of plateosaurian sauropodomorph that lived in Germany during the Late Triassic.
History[]
It is named after Amanz Gressly, the discoverer and excavator of the holotype from Niederschöntal, which is now called Füllinsdorf. Originally, they were identified as Belodon but were later confirmed as the first Swiss dinosaur. The erection of Gresslyosaurus followed by three additional species, of which only one remains. Heer (1865) briefly synonymized it with Teratosaurus, which was rejected. Galton (1986) reexamined the remains and sunk them within Plateosaurus, which had been accepted until only recently. Gressly worked closely with Louis Agassiz until he was admitted to extended psychiatric care several times. Most notably, his admission to an insane asylum following a mental breakdown where Gressly had thought that he was slowly transforming into his Gresslyosaurus. This detail was provided by Heer (1865) and unsourced, though his personal relation to Gressly suggests that some truth may be in such a claim. The discovery of Gresslyosaurus was minor in Gressly's life, so the reason for this is unclear and Gressly's attachment to the genus remained mysterious until his death by a stroke in April 1865. Galton (1986)'s analysis was heavily criticized. One of such in 2003 noted great differences in the vertebrae. Rauhut and Furrer (2020) erected Schleitheimia, which may be the same taxon as Gresslyosaurus. They found that although data from Gresslyosaurus is sparse, they exhibit taxonomic differentiation and may either be a new taxon, or the same as their own (in which case, Gresslyosaurus takes priority). Further analysis is in preparation.
Classification[]
Rütimeyer (1856) coined the name Dinosaurus gresslyi in an abstract, but was remixed as G. ingens due to Dinosaurus being preoccupied. Lydekker (1888) sunk the taxon into Zanclodon, but von Huene (1908) suggested the removal of all sauropodomorph material from Zanclodon, of which he thought was a theropod, and placed the remains into Plateosaurus. In the twentieth century, numerous authors declared it valid and invalid, culminating with modern work demonstrating plausible validity.