Overview
- Peer-reviewed findings in Nature Ecology & Evolution describe Haolong dongi from northeastern China’s Early Cretaceous Yixian Formation.
- The nearly complete juvenile preserves skin down to cellular structures, with scales and cornified spikes validated by imaging and histology.
- Integument includes large overlapping scales along the tail plus small tuberculate body scales interspersed with spikes of varying sizes.
- The longest documented spike measures 44.2 millimetres, and the uniform hollow, cylindrical form differs from protofeathers and reptile spines.
- Authors place the species near the base of the hadrosauroid lineage and hypothesize predator deterrence as the primary spike function, with possible thermoregulatory or sensory roles; the name honors Dong Zhiming.