A research team from Sidi Mohamed Ben Abdela University, the University of Birmingham, and the Museum of Natural History in London has identified a new specimen as the oldest known Serapodan Ornithischian dinosaur.
Proximal femurs of the Serapodan dinosaur from the Elmers III Formation in the Central Atlas Mountains of Morocco. Image credit: Maid et al., doi: 10.1098/rsos.241624.
“Serapod has received significant attention lately,” said Dr. Susanna Maid, a paleontologist at the Museum of Natural History, University of Birmingham.
The early Serapodan, a key player in the Cretaceous terrestrial ecosystem, was bipedal and featured hadrosaur-like skeletal structures. In contrast, late Cretaceous forms, including hadrosaurs and ceratopsids, evolved more specialized adaptations.
“Serapodans can be divided into two major clades: Ornithopoda, which encompasses non-hadrosaur Iguanodons and duck-billed Hadrosaurs, and Margin Osephalia, which includes horned and dome-headed species like Pachycephalosaurs.”
“While Serapodans are well-documented from the Cretaceous, their presence in the Jurassic is less established,” the researchers noted.
“Various Jurassic tracksites indicate that sizable ornithopods (likely related to Iguanodon) had emerged by this time, yet body fossils remain scarce.”
“There’s a pressing need for additional specimens from historically underrepresented regions to help clarify the early evolution of Serapodans and resolve ongoing phylogenetic discrepancies.”
A new specimen, representing part of a left femur, was collected from the Elmers III Formation in Boulafa, near Bruman in Morocco’s Middle Atlas Mountains in 2020.
These fossils date to the Basonian stage (Central Jurassic), approximately 165 to 160 million years ago.
The diverse green and red mudstones of this formation have yielded significant fossils, including Africa’s oldest known antirosaurus, Spicomellus afer, and one of the oldest Stegosaurus species, Adratiklit boulahfa.
The newly identified specimen is now recognized as the oldest Serapodan, adding valuable data to our understanding of Central Jurassic taxa.
“Despite its fragmentary nature, the specimen exhibits key features, including a distinct neck of the femoral head and a noticeable relationship between the head and the greater trochanter.”
“Further exploration and sampling of Elmers III Formation in Morocco are crucial for deepening our understanding of Oritesian dinosaur evolution during the Central Jurassic.”
The research team’s study was published in the journal Royal Society Open Science on March 12, 2025.
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Susanna Maid et al. 2025. The world’s oldest Serapodan Ornithischian dinosaur from the Jurassic of central Morocco. R. Soc. Open Sci 12(3): 241624; doi: 10.1098/rsos.241624
Source: www.sci.news
