Paleontologists have identified a new species of dinosaur so small it could almost fit under your arm—and yet it is helping scientists solve a major evolutionary mystery.
The dinosaur, named Foskeia pelendonum, lived during the Early Cretaceous period and measured only about half a meter from head to tail.
Despite its tiny size, it is proving to be a crucial missing link in the evolution of plant-eating dinosaurs in Europe.
The discovery was made at the Vegagete fossil site in Burgos, northern Spain, and described by an international research team led by Paul-Emile Dieudonné of the National University of Río Negro.
The study was published in Papers in Palaeontology.
At first glance, Foskeia stands out simply because of its extreme smallness. But what truly surprised researchers was its skull.
Although the animal was tiny, its head shows highly specialized and unusual features that are typically seen in much more evolutionarily advanced dinosaurs.
This combination of small body size and complex anatomy challenges the idea that early or small dinosaurs were anatomically simple.
The fossils represent at least five individuals and were first discovered by paleontologist Fidel Torcida Fernández-Baldor from the Dinosaur Museum of Salas de los Infantes. From the start, the researchers knew they had found something unusual. Not only were the bones remarkably small, but their anatomy suggested a dinosaur that did not fit neatly into existing evolutionary categories.
The name Foskeia comes from ancient Greek words meaning “light” and “foraging,” reflecting the animal’s lightweight body and plant-eating lifestyle. The species name pelendonum honors the Pelendones, a Celtic tribe that once lived in the region where the fossils were found.
Further analysis showed that Foskeia belonged to a group of small, bipedal herbivorous dinosaurs called ornithopods. More importantly, it appears to sit near the base of a European lineage known as Rhabdodontidae. Until now, scientists faced a roughly 70-million-year gap in the fossil record for this group. Foskeia helps bridge that gap, offering new insight into how these dinosaurs evolved.
Bone studies provided another surprise. Histological analysis, led by Dr. Koen Stein of the Vrije Universiteit Brussel, revealed that the largest specimen was a fully grown adult. This confirms that Foskeia was genuinely small, not a juvenile of a larger species. Its bone structure suggests a fast metabolism, closer to that of modern birds or small mammals than to slower-growing reptiles.
The team’s evolutionary analysis also reshaped the dinosaur family tree. Foskeia appears closely related to Muttaburrasaurus from Australia, suggesting unexpected links between dinosaurs from distant parts of the world. The results even revive an old hypothesis that plant-eating dinosaurs form a single natural group, a concept known as Phytodinosauria.
In life, Foskeia likely relied on speed and agility to survive in dense forests, using its specialized teeth to process plants efficiently. Its discovery is a reminder that evolution does not only produce giants like Tyrannosaurus or Brachiosaurus.
Sometimes, the smallest creatures carry the biggest scientific importance—and Foskeia is one of them.
