Chinese paleontologists have discovered the nearly complete skeleton of a previously unknown species of iguanodont dinosaur. The skeleton preserves highly detailed fossilized skin, including structures not found in non-avian dinosaur fossils.

Hao London Gi It lived in what is now northeastern China during the Early Cretaceous period, about 125 million years ago.

The new species were of the following types: iguanodoniana major group of ornithopod dinosaurs.

Evolutionarily, they fall between the early small bipedal ornithopods and the later, highly specialized duck-billed dinosaurs (hadrosaurs).

“Iguanodontia was the dominant herbivorous dinosaur in most terrestrial ecosystems throughout the Cretaceous,” said Dr. Pascal Godefroy of the Institute of Natural Sciences in Brussels and his colleagues.

“This clade reached its peak in the final stages of this era, as hadrosaurids, or duck-billed dinosaurs, spread across most continents.”

“The remarkable discoveries of ‘mummies’ from North America and Mongolia have revealed valuable information about the integument of hadrosaurids. The integument was composed of a complex, often mosaic arrangement of tuberous and non-interdigitated scales, with expanded plate-like scales along the dorsal midline.”

“In contrast, less information is available about the integument of more basal iguanodonts, with only isolated patches of scaly traces known. tenontosaurus, iguanodon and Mantellisaurus It suggests a scale pattern reminiscent of hadrosaurids. ”

Fossil skeleton of a juvenile 2.45 meters long Hao London Gi was recovered from Yixian layer.

This specimen is notable not only for the quality of its bones, but also for the excellent preservation of its integument.

The fossil contains overlapping scales on the tail and distinct nodular scales on the neck and thorax, a pattern markedly different from previously described iguanodonts.

But the most striking thing are the skin spines dotted between the scales.

Using advanced image processing and microscopic analysis, paleontologists discovered that these spikes were hollow, cylindrical, and consisted of a highly keratinized outer layer over a multilayered epidermis, with keratinocytes preserved down to the nucleus. At the center of each spike is a porous dermal pulp.

This anatomy distinguishes spikes from both protofeathers found in some other dinosaurs and scaly spines found in modern lizards, suggesting an independent evolutionary origin.

The shape and placement of the spikes suggest that they primarily served as a deterrent against predators, but may also have played a role in thermoregulation and sensory perception.

“This discovery provides unprecedented insight into the skin microanatomy of non-avian dinosaurs and highlights the complexity of skin evolution in ornithischian dinosaurs,” the researchers concluded.

The discovery of a new species of dinosaur is reported in a magazine. paper in diary natural ecology and evolution.

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J.Fan others. Cellular preservation of skin spikes in early Cretaceous iguanodont dinosaurs. Nat Ecole Evolpublished online on February 6, 2026. doi: 10.1038/s41559-025-02960-9