Overview
- The peer-reviewed description in Nature Ecology & Evolution names Haolong dongi, a juvenile iguanodontian from the Early Cretaceous Yixian Formation in northeastern China (~125 million years old).
- The holotype preserves extensive integument, including overlapping scales on the tail and tuberculate scales on the neck and torso that differ from previously described iguanodontians.
- Advanced imaging and histology show hollow, near-cylindrical spikes composed of hardened keratin, with microstructures preserved down to individual keratinocyte nuclei and a porous dermal pulp core.
- Researchers interpret the spikes as primarily a predator deterrent, with possible thermoregulatory or sensory functions suggested by their form and distribution.
- The specimen (about 2.45 meters long) is a juvenile, the genus name means “spiny dragon,” and the species honors pioneering Chinese paleontologist Dong Zhiming.