Spiny-armed Haolong dongi: a new Chinese iguanodontian reshapes dinosaur skin lore
A new Chinese dinosaur, Haolong dongi, a 2.4 m juvenile iguanodontian, shows remarkable soft-tissue preservation including backward-projecting bristly spines along the neck and body and nine rows of tail scales. The hollow, porcupine-like spikes and mixed scales reveal a greater diversity of skin coverings in ornithischians than previously known, beyond simple scales or feathers. Adults were likely around 5 m. Discovered in a cool environment and published in Nature Ecology & Evolution, the find prompts questions about the functions of the spikes (defense or display rather than insulation or sensing) and suggests vertebrate integumentary diversity may be more complex than imagined.