Foskeia pelendonum is half a meter long. It is not a juvenile. Bone histology confirms it was a fully grown, sexually mature adult ornithopod from the Early Cretaceous of Spain. Its skull is unexpectedly derived, placing it near the base of Rhabdodontidae and linking European and Australian ornithopod lineages separated by oceans.
Before Foskeia, a 70-million-year gap separated the earliest rhabdodontids from their nearest relatives. The gap suggested either a long period of evolutionary stasis or a missing branch of the tree. Both interpretations assumed the fossil record was reporting accurately at small body sizes. It was not.
Paleontology has a size bias. Larger specimens are easier to find, easier to identify as significant, and easier to fund expeditions around. The fragmentary, the small, and the humble are systematically undersampled. This is not a secret — every paleontologist knows it. But knowing about a bias and correcting for it are different operations. The gap persisted not because the fossils were absent but because the search image was calibrated to larger animals.
Foskeia shows that evolution was experimenting at small body sizes with the same radicality it showed at large ones. The derived skull features are not what you expect from a basal rhabdodontid. They are what you expect from a lineage that has been evolving for the 70 million years the record was supposedly empty. The lineage was there. The record was not looking.
The correction is not technical. It is attentional. The instruments were adequate. The sites were known. The missing variable was the decision about what counts as worth collecting. A half-meter dinosaur in a world of multi-ton sauropods is easy to overlook. But the information it carries — phylogenetic placement, biogeographic connection, morphological innovation — is not proportional to its size.