Paleontologists have unearthed the skeletal remains of a completely new and unnamed Masopodan Sauropodmorph dinosaur in the Cretgau Formation of Canton Aargau, Switzerland.
Clear skull of a new Masopodian sauropod dinosaur in view on the right. Scale bar – 5 cm. Image credits: Lanier et al., doi: 10.1186/s13358-025-00373-6.
The newly found fossil is estimated to be from the late Triassic Epoch Norian period, around 206 million years ago.
This dinosaur was previously associated with an unidentified member of Masopoda, a vast group of Sauropodmorph dinosaurs that existed during the late Triassic to late Cretaceous epochs.
“Among Mesozoic terrestrial vertebrates, Sauropodomorpha stands out as one of the most successful dinosaur clades, becoming a dominant herbivore component in both Late Triassic and Jurassic paleoecosystems, with a wide global distribution from Antarctica to Greenland,” stated Dr. Alessandro Lania from the Rheinische Friedrich-Wilhelms-Universität Bonn and his Swiss colleagues.
“The origin of Sauropodmorph can be traced back to the early late Triassic on the Gondwanan continent, with the oldest examples found in Brazil, Argentina, South Africa, and North America.”
“Based on the South American fossil record, we offer a detailed understanding of the early evolution of sauropods, moving away from a limited number of strains characterized by small size, bipedal locomotion, and a carnivorous diet. This heralds a shift to medium and large body plans, quadrupedal dynamics, and a transition to herbivorous habits in the Norian-Flyzia period.”
Moreover, this notable increase in the diversity of Sauropodmorph in South Pangea during the Norian period is evident through the emergence of new major lineages like Masopoda and Sauropodiformo, marking a significant morphological divergence.
The partially complete skeleton of the new Masopodan Sauropodmorph was discovered in 2013 at the top of the fossil horizon within the Gruharde members of the Kretgau Formation in Flick, Canton Aargau, Switzerland.
“The Kretgau Formation represents one of the most extensive stratigraphic sequences of the Late Triassic in Europe, consisting of a diverse, petrologically heterogeneous series of deposits spanning approximately 26 to 30 million years, from early Karnians to late Lechan,” explained the paleontologist.
“The Kretgau Formation can be seen in various locations across Switzerland, documenting discontinuous sequences of varied Playa deposits influenced by river and oceanic processes, reflecting several lateral paleoenvironmental shifts throughout the stratigraphy.”
This new specimen signifies the first den Plate Saurus of the Canton Aargau sauropods and Swiss sauropods from the 4th Triassic, distinguishing them from non-Sauropodian Sauropodmorph.
“Osteologic investigations combined with morphological comparisons have clarified the anatomy of mosaic cranial cephalogenesis, integrating typical features of non-masopodian plasal aurians and Masopodian sauropods, like Coloradisaurus Brevis from Argentina,” the researcher commented.
According to the authors, this dinosaur represents the first non-Sauropod-type masopodian from Laurasia.
“Interestingly, this scenario raises the hypothesis of the European origins of early Jurassic Masopodans from late Triassic Asia, though more evidence is needed to substantiate this,” they stated.
“Additionally, these fossils enhance our understanding of cranial variability and body diversity in Norian sauropodomorphs in Laurasia, paralleling those in Gondwana, particularly in South America and Africa.”
The team’s paper was published this month in the Swiss Journal of Palaeontology.
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A. Rania et al. 2025. Cranial osteology of the new Masopodan Sauropodmorph (dinosaurs: saury) from the late Triassic period (latest Norian) of Switzerland. Swiss J Palaeontol 144, 39; doi:10.1186/s13358-025-00373-6
Source: www.sci.news
