The new specimen represents the oldest dinosaur of ornithischian Cerapodan in the world, according to a team of paleontologists from Sidi Mohamed Ben Abdellah University, the University of Birmingham and the Natural History Museum, London.
The proximal femur of a Cerapodan dinosaur of the El Mers III formation of the Middle Atlas mountains, Morocco. Image credit: Maidure and al., TWO: 10.1098 / RSOS.241624.
“Cerapoda is a diversified clade of ornithischian dinosaurs with global distribution,” said Dr. Susannah Maidment, paleontologist of the Natural History Museum, London, and the University of Birmingham, and colleagues.
“A major component of terrestrial ecosystems in the Cretaceous, the first divergent ceravodes were bipedal, with previous members modified for the seizure, but by the upper Cretaceous, the Hadrosaurides and the Ceratopside had evolved quadruped and the sophisticated chewing mechanisms.
“Cerapoda is made up of two major clades: ornithopoda, which includes non -hadrosaurid iguanodontians and duck beak, marginocephalies, which includes ceratopsians in Corned and pachyceceaurs with a dome head.”
“Cerapodans are well known to the Cretaceous period, but their Jurassic file is much poorer,” they noted.
“Several trail sites of the middle Jurassic suggest that large -body ornithopods – probably the Iguanodontians – had already evolved at that time, but their body fossils remain elusive.”
“To elucidate the first stages of Cerapoda’s evolution and to help resolve the many phylogenetic inconsistencies between different analyzes, new specimens are necessary, in particular from historically underchant localities.”
The new specimen of Cerapodan – part of a left femur – was collected on the surface in 2020 in the formation of El Mers III in Boulahfa, near Boulemane, Mountains du Middle Atlas, Morocco.
The fossil is Bathonian (average Jurassic) and date between 165 and 160 million years.
“The mudstones green and red variegated in the training are extremely fossiliferous and have so far gave the remains of the oldest and oldest ankylosaurs in the world, SPICOMELLUS AFERand one of the oldest Stegosaurs, Adratiklit Boulahfa“Said paleontologists.
The new specimen is the oldest cerapodan in the world and only the second recorded of the world’s Jurassic in the world.
“The specimen, although fragmentary, supports the characteristics, including a offbeat femoral head on a separate neck and a constriction between the head and the greatest trochanter, which unites it with Cerapoda to the exclusion of other neornithischians,” said the researchers.
“The other sampling of the El Mers III training in Morocco is crucial to understand the average jurassic influence of ornithischian dinosaurs.”
The team’s article was published on March 12, 2025 in the newspaper Royal Society of Open Sciences.
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Susannah Maidment and al. 2025. The oldest ornithischian dinosaur in the world of the world of the average Jurassic in Morocco. R. Soc. Dynamism 12 (3): 241624; Two: 10.1098 / RSOS.241624
