Open Paleo

Magyarosaurus

Huene, 1932 MOD-yar-o-SAWR-us

From Hungarian 'Magyar' meaning 'Hungarian' and Greek 'sauros' meaning 'lizard'; named for Hungary, the country that controlled the Transylvanian region where it was found at the time of discovery.

72.2–66.0 million years ago Maastrichtian, Late Cretaceous
Late Cretaceous stages

Magyarosaurus is a genus of dwarf sauropod dinosaur from late Cretaceous Period (early to late Maastrichtian) in today's Transylvania. It is one of the smallest-known adult sauropods, measuring less than 3 m (9.8 ft) long and weighing less than 1,000 kg (2,200 lb). The type and only species is Magyarosaurus dacus. It has been found to be a close relative of Rapetosaurus in the family Saltasauridae in the sauropod clade Titanosauria in a 2005 study.

Diagnosis

  1. Anterior caudal centra with ventrolateral ridges but without a midline furrow
  2. Well-developed bulge on the posterior surface of the humerus, presumably the site for M. latissimus dorsi, positioned approximately equidistant from the medial and lateral margins
  3. Interosseous ridge of the ulna strongly distolaterally oriented, its proximal end intersecting the anteromedial margin of the shaft
  4. Low eccentricity of the femoral midshaft, 1.1-1.4
  5. Subtle ridge on the anterior margin of the lateral surface of the fibula, its proximal tip at approximately the level of the distal end of the lateral trochanter

Species

Magyarosaurus dacus (Nopcsa, 1915)

Type species

First named as Titanosaurus dacus

Named for the Dacians, the ancient people who inhabited the Transylvanian region of present-day Romania approximately two thousand years ago.

Lectotype
SZTFH Ob.3091 , Hungarian Geological Survey
Material
Anterior caudal vertebra; sides approximately parallel in cross-section, slightly concave, centrum no narrower below than above
Horizon
middle Densuș-Ciula Formation, Maastrichtian, Late Cretaceous , 72.2–66.0 million years ago
Locality
Kadić Locality I, Pârâul Vârtopilor, near Valioara, Hunedoara, Romania

Synonyms

  • Magyarosaurus transsylvanicus junior subjective

    Erected by Huene (1932); shown to be a chimaera drawing on the type assemblage of M. dacus, a further individual, and indeterminate titanosaurs, and so invalid and in part a junior synonym of M. dacus.

References

  1. Nopcsa, B. F. (1915). Die Dinosaurier der siebenbürgischen Landesteile Ungarns [The Dinosaurs of the Transylvanian Territories of Hungary]. Mitteilungen aus dem Jahrbuche der Königlich Ungarischen Geologischen Reichsanstalt 23: 1-26.

    In German. Original description, as Titanosaurus dacus.

    nopcsa1915a
  2. Huene, F. V. (1932). Die fossile Reptil-Ordnung Saurischia, ihre Entwicklung und Geschichte [The fossil reptile order Saurischia, their development and history]. Monographien zur Geologie und Palaeontologie, serie 1 4(1-2): 1-361.

    Reassigns Titanosaurus dacus to Magyarosaurus.

    huene1932a
  3. Díez Díaz, V.; Mannion, P. D.; Csiki-Sava, Z.; Upchurch, P. (2025). Revision of Romanian sauropod dinosaurs reveals high titanosaur diversity and body-size disparity on the latest Cretaceous Haţeg Island, with implications for titanosaurian biogeography. Journal of Systematic Palaeontology 23(1). Informa UK Limited. doi:10.1080/14772019.2024.2441516

    Revision of the Romanian sauropods. Confirms the lectotype, gives a revised autapomorphy-based diagnosis, and places the type locality at Valioara rather than Sânpetru.

    díezdíaz2025a
  4. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

    Source of the hip height estimate, and the appearance features.

    jones2026b