China's 125-million-year-old dinosaur fossil reveals preserved skin, strange spikes and a previously unknown species

Fossils often preserve bones well enough to reveal the shape of an ancient animal, but traces of soft tissues are much less common. That is why a newly described dinosaur from north-eastern China has drawn such close attention from palaeontologists. Dating back around 125 million years to the Early Cretaceous period, the specimen offers more than a skeleton. Extensive patches of preserved skin have given scientists a rare chance to examine the animal’s outer covering in unusual detail, revealing features that have not previously been documented in dinosaurs.

A 125-million-year-old fossil reveals a previously unknown dinosaur

The dinosaur has been named Haolong dongi and belongs to the iguanodontians, a group of herbivorous dinosaurs that were widespread during the Early Cretaceous. Although relatives within this family have been studied for decades, this newly described species stands apart because of the condition of the fossil rather than its bones alone.The remains were uncovered in north-eastern China by an international research team led by the Anhui Geological Museum in collaboration with the Institute of Natural Sciences in Belgium. As reported by The French National Centre for Scientific Research (CNRS), fossils have been dated to roughly 125 million years ago, placing the animal in an ecosystem that supported a wide range of dinosaur species living alongside one another.

PC: ScienceAlert

What the fossil’s preserved skin revealed

While fossilised skin has occasionally been found with dinosaurs before, complete sections are exceptionally uncommon. In this specimen, preserved skin extends across sizable parts of the body, allowing researchers to study details that are usually lost long before fossilisation takes place.According to the scientists involved in the study, the preserved tissue shows a surprisingly varied surface rather than a single uniform texture. Different parts of the body carried different types of scales, suggesting dinosaur skin could be more specialised than earlier discoveries had indicated.The preservation is detailed enough to provide information at an extremely fine level, offering clues that bones alone cannot reveal about the appearance and biology of the animal.

Why it became known as the ‘spiny dragon‘

One feature immediately caught the attention of the research team. Across much of the dinosaur’s body were spike-like structures of different lengths, giving the species a distinctive appearance that inspired the nickname “spiny dragon”.Its tail was covered with large overlapping scales, while the rest of the body displayed both shorter and longer spines. Scientists say this combination has not previously been recorded in dinosaurs, making Haolong dongi unlike any known relative described so far.The varied arrangement suggests the spikes were not distributed randomly but formed part of the animal’s normal body covering.

Possible roles for the unusual spikes

Exactly why the dinosaur evolved these structures remains uncertain. One explanation is that the spikes provided a physical defence against predators sharing the same habitat. An animal covered in sharp projections would have been less straightforward to seize or swallow.Other possibilities remain under consideration. The structures may have assisted with regulating body temperature or acted as sensory features that helped the dinosaur respond to its surroundings. At this stage, the fossil cannot provide a definitive answer, although it gives scientists new evidence to compare with other species.As additional discoveries emerge, researchers hope they will be able to determine whether these spines were unique to Haolong dongi or part of a wider pattern among related dinosaurs.

What makes this fossil exceptionally important

The specimen is also significant because of the quality of preservation. Soft tissues usually disappear long before fossilisation can occur, making discoveries like this uncommon even in fossil-rich regions.Members of the research team said the preserved skin has revealed a level of complexity that exceeded expectations. Rather than presenting a simple outer covering, the fossil points towards a body surface with considerable variation in texture and structure.Scientists believe these details will contribute to a better understanding of dinosaur anatomy, helping reconstruct how different species looked in life and how their skin may have functioned beyond simply covering the body.