Adynomosaurus
A weakly-shouldered hadrosaur from Late Cretaceous Spain.
Adynomosaurus is a genus of lambeosaurine hadrosaurid dinosaur from the Late Cretaceous of what is now Catalonia, Spain. First discovered in 2012 and named in 2019, it is known only from scant material, including a distinctive, weakly developed shoulder blade that suggests underdeveloped musculature. Its exact relationships with other hadrosaurs remain unresolved, with some studies placing it within Lambeosaurinae and others outside Hadrosauridae.
- field
- Paleontology
- known_for
- Weakly developed scapula indicating reduced forelimb musculature
- type_species
- Adynomosaurus arcanus
- discovery_year
- 2012
- naming_year
- 2019
- location
- Catalonia, Spain
Lore & Background
Adynomosaurus was discovered at the Costa de les Solanes locality of the Conques Formation in 2012, in a wheat field near the village of Basturs in Catalonia. Researchers from the Institut Català de Paleontologia Miquel Crusafont and the Universitat Autònoma de Barcelona excavated the site during 2012 and 2013, recovering associated but disarticulated remains from at least two individuals. The holotype specimen, MCD 7125, is a left scapula, chosen for being the most diagnostic element. The genus name combines Greek words for 'weak', 'shoulder', and 'lizard', referencing the underdeveloped scapula, while the species name arcanus means 'secret' or 'occult', alluding to the sparse hadrosaur fossil record in the region.
Reader's Guide
Adynomosaurus adds to the very incomplete fossil record of hadrosaurid dinosaurs in the Late Cretaceous of Europe, fitting into a picture of major ecological turnover during the Maastrichtian stage. Its weakly developed scapula, with a blade only 75% the width of the proximal end and a very thin constriction, is unique among hadrosaurs and suggests reduced strength in arm movements such as abduction and adduction. However, the correlation between bone size and musculature is uncertain. The taxon's phylogenetic position remains debated: some analyses place it in a polytomy at the base of Lambeosaurinae, others within the clade Arenysaurini or Tsintaosaurini, and still others outside Hadrosauridae entirely. This uncertainty highlights the fragmentary nature of the European Late Cretaceous hadrosaur record and the ongoing need for more complete specimens.
Did You Know?
- Adynomosaurus is known from only scant material, including a partial left dentary, vertebrae, a left scapula, a left sternum, a partial rib, and pelvic and hindlimb bones.
- Its scapula is proportionally the shortest of all hadrosaurs, though this cannot be definitively confirmed due to incompleteness.
- The species name arcanus means 'secret' or 'occult', referring to the poor fossil record of hadrosaurs in the South-Central Pyrenean Basin.
- Adynomosaurus lived in a coastal estuary ecosystem with meandering rivers and mud flats on the Ibero-Armorican island.
More in Dinosaur genera 1-24
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