[2] Remains belonging to at least ten individuals have been recovered from the Hunedoara region (Sânpetru Formation) in the area which was, at the time of their discovery, Hungary, but is now western Romania.

[6] Paleontology investigations have been carried out at Râpa Roșie near Sebeş, on the southwestern side of the Transylvanian Basin.

Paleontologists involved with the studies at Râpa Roșie have also opined that this is the only sauropod genus reported at any time in the latest Cretaceous Maastrichtian formations in Romania, which could be stated as Magyarosaurus.

[1] Magyarosaurus was a relatively small sauropod, reaching 6 m (20 ft) in length and 750–1,000 kg (1,650–2,200 lb) in body mass.

It is assigned to Magyarosaurus on the basis that no other sauropods are known from the region it was found in, and the fact that it is located between the two vertebrae compared with it because of its intermediate morphology.

[1] The islands it inhabited led to Magyarosaurus becoming a product of insular dwarfism as a result of selective pressures presented by limited food supplies and a lack of predators, all favoring a smaller body size.

Nopcsa was the first to suggest island dwarfism as an explanation for the small size of Magyarosaurus compared to other sauropods.

However, a detailed study of bone growth patterns published in 2010 supported Nopcsa's original hypothesis, showing that the small Magyarosaurus individuals were adults.

[10] The osteoderms was peculiar in shape and size,[10] and led to eggs being assigned to its family, Nemegtosauridae, and possibly to Magyarosaurus.

However, during the later age of the formation, a large-scale paleoenvironmental change occurred, the region transformed into an extensive wetland.

[12] Magyarosaurus dacus is known from the early Maastrichtian of the Sânpetru Formation, part of the Hațeg Basin in Romania.

Alongside Magyarosaurus existed Kallokibotion, an ancient turtle;[1] Balaur, a two-clawed avialan;[14] and Eurazhdarcho, an azhdarchid.