Fona

Fona is a small herbivorous ornithopod discovered in the mid-Cretaceous rocks of Utah. Measuring around two metres from snout to tail tip, it was comparable in stature to a large dog, weighing roughly fifteen to thirty kilograms. Described in 2024 from multiple fossil specimens, Fona shows skeletal features indicative of a semifossorial lifestyle, including robust forearms, enlarged shoulder attachments, and sturdy feet adapted for excavation. Many skeletons were recovered from deposits that represent infilled burrows, suggesting that spending time underground was a widespread ecological strategy among its group rather than an isolated quirk. Fona used a small, sharp beak and serrated cheek teeth to browse low plants across warm semi-arid river systems.

Multiple individuals found preserved inside collapsed subterranean tunnels indicate that burrowing was common among early thescelosaurids.

Where and when

Fona lived in the Late Cretaceous, from 100 to 97 million years ago (Cenomanian age). Its remains come from United States, in the Cedar Mountain Formation.

The numbers

Length 1.9 m (estimates run from 1.5 to 2.2 m). Mass about 21 kg. Hip height about 0.6 m. That is 1.1 human-lengths, or 0.17 of a double-decker bus. These are estimates from partial skeleton; fields marked estimated by the site are length, mass, hip height.

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