Scientists from several countries have identified a new dinosaur species called Foskeia pelendonum, a very small plant-eating dinosaur that lived during the Early Cretaceous. The fossils were found in Vegagete (Burgos, Spain), and the animal measured only about half a meter in length. The research team was led by Paul-Emile Dieudonné (National University of Río Negro, Argentina). Their analysis shows that Foskeia had a surprisingly advanced skull and likely appeared close to the earliest branches of the European plant-eating dinosaur group Rhabdodontidae.
“From the very first moment anybody sees this animal one is staggered by its extreme smallness,” says Dieudonné. “And yet it preserves a highly derived cranium with unexpected anatomical innovations.”
Fossil Discovery Reveals an Unexpected Dinosaur
The fossils belong to at least five individuals and were originally discovered by Fidel Torcida Fernández-Baldor of the Dinosaur Museum of Salas de los Infantes. The unusually small size of the bones immediately caught researchers’ attention.
“From the beginning, we knew these bones were exceptional because of their minute size. It is equally impressive how the study of this animal overturns global ideas on ornithopod dinosaur evolution,” he explains.
Meaning Behind the Name Foskeia pelendonum
The name Foskeia comes from ancient Greek. The prefix fos means ‘light’, a reference to the lightweight build and very small body size of adult individuals (Dieudonné et al. 2023). The letters ‘skei’ come from boskein, meaning foraging. The species name pelendonum honors the Pelendones, a Celtiberian tribe that once lived in the Fuentes del Duero region (north of the province of Soria, southeast of Burgos and perhaps the southeast of La Rioja).
Why Foskeia Changes Views on Dinosaur Evolution
Researchers say Foskeia carries major evolutionary importance despite its size. Marcos Becerra (Universidad Nacional de Córdoba) highlights how unusual the animal truly is: “Miniaturization did not imply evolutionary simplicity — this skull is weird and hyper-derived.”
Thierry Tortosa (Sainte Victoire Natural Reserve) emphasizes its broader significance: “Foskeia helps fill a 70-million-year gap, a small key that unlocks a vast missing chapter.”
Tábata Zanesco Ferreira (Universidade Federal do Rio de Janeiro) adds: “This is not a ‘mini Iguanodon’, it is something fundamentally different.”
According to Penélope Cruzado-Caballero (Universidad de La Laguna), “Its anatomy is weird in precisely the kind of way that rewrites evolutionary trees.”
Bone Analysis Confirms Adult Size and Fast Growth
Microscopic examination of the bones, overseen by Dr. Koen Stein (Vrije Universiteit Brussel), confirmed that the largest fossil specimen came from a fully mature adult dinosaur. The internal structure of the bones provided key insights into how Foskeia grew and lived.
“Bone microstructure tells us that at least one individual was an adult… with a metabolic regime approaching that of small mammals or birds. Knowledge of growth and development is essential if we want to compare the anatomy of Foskeia with other species. Young individuals are prone to changes in anatomical features as they grow,” Stein explains.
A New Place on the Dinosaur Family Tree
Using updated evolutionary data, the research team placed Foskeia as a close relative of the Australian dinosaur Muttaburrasaurus, within the broader group Rhabdodontomorpha. This finding also expands the known diversity of the European clade Rhabdodontia.
The analysis also supports a renewed version of a long-debated grouping called Phytodinosauria. “In our results, the plant-eating dinosaurs… form a natural group called Phytodinosauria,” says Dieudonné. “This hypothesis should be further tested with more data.”
Small Dinosaur, Specialized Way of Life
Although Foskeia was tiny, it showed clear signs of specialization. The dinosaur had distinctive teeth and appears to have changed posture as it grew, likely relying on quick bursts of speed to move through dense forest environments.
“These fossils prove that evolution experimented just as radically at small body sizes as at large ones,” Dieudonné says. “The future of dinosaur research will depend on paying attention to the humble, the fragmentary, the small.”
Reference: “Foskeia pelendonum, a new rhabdodontomorph from the Lower Cretaceous of Salas de los Infantes (Burgos Province, Spain), and a new phylogeny of ornithischian dinosaurs” by Paul‐Emile Dieudonné, Marcos Gabriel Becerra, Tábata Zanesco, Thierry Tortosa, Penélope Cruzado‐Caballero, Koen Stein, Fidel Torcida Fernández‐Baldor, January 2026, Papers in Palaeontology.
DOI: 10.1002/spp2.70057
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