A new genus and species of diminutive bipedal dinosaur has been identified from the fossils found in Burgos province of Spain.
Life reconstuction of Foskeia pelendonum. Image credit: Martina Charnell.
Foskeia pelendonum roamed our planet during the Early Cretaceous epoch, around 120 million years ago.
The new species was a member of Rhabdodontomorpha, a group of ornithischian dinosaurs that lived mainly during the Early to Late Cretaceous.
The ancient animal was diminutive, roughly comparable in size to a modern chicken, marking it distinct from many of its larger ornithischian relatives.
“From the beginning, we knew these bones were exceptional because of their minute size,” said Dr. Fidel Torcida Fernández-Baldor, a paleontologist at the Dinosaur Museum of Salas de los Infantes.
“It is equally impressive how the study of this animal overturns global ideas on ornithopod dinosaur evolution.”
“Miniaturization did not imply evolutionary simplicity — this skull is weird and hyper-derived,” added Dr. Marcos Becerra, a paleontologist at the Universidad Nacional de Córdoba.
“Foskeia pelendonum helps fill a 70-million-year gap, a small key that unlocks a vast missing chapter,” said Dr. Thierry Tortosa, a paleontologist at the Sainte Victoire Natural Reserve.
“This is not a ‘mini Iguanodon,’ it is something fundamentally different,” said Dr. Tábata Zanesco Ferreira a paleontologist at the Universidade Federal do Rio de Janeiro.
“Its anatomy is weird in precisely the kind of way that rewrites evolutionary trees,” said Dr. Penélope Cruzado-Caballero, a paleontologist at the Universidad de La Laguna.
The fossilized remains of at least five individuals of Foskeia pelendonum were collected from the Vegagete site in Burgos province, Spain.
“The site consists of the red-clay floodplain deposits of the Castrillo de la Reina Formation, and lies between the Villanueva de Carazo and Salas de los Infantes municipalities,” the paleontologists said.
A histological analysis confirmed that the largest specimen was a sexually mature adult.
“Bone microstructure tells us that at least one individual was an adult with a metabolic regime approaching that of small mammals or birds,” said Dr. Koen Stein, a researcher at Vrije Universiteit Brussel.
“Knowledge of growth and development is essential if we want to compare the anatomy of Foskeia pelendonum with other species.”
“Young individuals are prone to changes in anatomical features as they grow.”
According to the phylogenetic analysis, Foskeia pelendonum is a sister species to the Australian dinosaur Muttaburrasaurus within Rhabdodontomorpha, and expands the European clade Rhabdodontia.
“In our results, the plant-eating dinosaurs form a natural group called Phytodinosauria,” said Dr. Paul-Emile Dieudonné, a researcher at the National University of Río Negro.
“This hypothesis should be further tested with more data.”
Despite its small size, Foskeia pelendonum shows specialized dentition and evidence of shifting posture during growth, relying on bursts of speed in dense forests.
“These fossils prove that evolution experimented just as radically at small body sizes as at large ones,” Dr. Dieudonné said.
“The future of dinosaur research will depend on paying attention to the humble, the fragmentary, the small.”
The discovery of Foskeia pelendonum is described in a paper published in the journal Papers in Palaeontology.
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l-Emile Dieudonné et al. 2026. Foskeia pelendonum, a new rhabdodontomorph from the Lower Cretaceous of Salas de los Infantes (Burgos Province, Spain), and a new phylogeny of ornithischian dinosaurs. Papers in Palaeontology 12 (1): e70057; doi: 10.1002/spp2.70057