Velociraptor mongoliensis, which lived in what is now Mongolia during the Late Cretaceous period, was comparatively small, separating the scientific reality from the popular myth of a large, scaly monster. It was roughly the size of a modern turkey or coyote, measuring about 1.8 meters in length (mostly tail) and weighing between 15 and 45 kilograms. While paleontologists understand its physical structure and size, the exact color of its plumage remains a mystery, requiring inference from indirect fossil evidence and biological analogy.
Establishing the True Appearance
The most significant correction to the popular image is the presence of feathers, fundamentally changing the surface upon which any color would have been displayed. Velociraptor was a member of the Dromaeosauridae family, a group of dinosaurs closely related to birds. Direct evidence for a feathered covering comes from a specific fossil discovery on the forearm bone, the ulna, of a Velociraptor specimen.
Scientists identified six distinct bumps running along the bone, known as quill knobs. These knobs are attachment points for the ligaments that anchor large secondary wing feathers to the skeleton in many modern birds. This finding confirms that Velociraptor possessed a sophisticated covering of feathers, including long, modern-looking feathers on its arms, despite being flightless.
The feathers were likely not used for flight, given the animal’s size and short forelimbs. They would have provided insulation, protected the nest, or been used for display. Since the animal was a feathered predator, its coloration would have been a pigment or structural color within the feather structure itself. The presence of prominent arm feathers suggests that color patterns would have been particularly visible in this area, perhaps for communication.
Decoding Color Through Fossil Evidence
Since pigments decay over millions of years, scientists use a microscopic technique to infer the original colors of extinct animals. This method relies on the preservation of melanosomes, which are tiny, pigment-containing organelles found within feather cells. These structures are far more durable than keratin and other organic materials, allowing them to fossilize.
The shape and density of fossilized melanosomes are compared to those in modern bird feathers to determine the original color. Elongate melanosomes (eumelanosomes) correlate with black or dark brown coloration, while more spherical ones (phaeomelanosomes) suggest a reddish-brown or rufous hue. Highly organized arrangements of melanosomes can also indicate structural colors, such as iridescence, which creates a metallic sheen.
While no Velociraptor fossil has preserved feathers with intact melanosomes, the technique has been successfully used on close relatives, such as Microraptor and Sinosauropteryx. This analysis confirmed that many non-avian dinosaurs possessed a range of colors, including black, brown, gray, and possibly iridescent sheens. The quill knobs on Velociraptor’s ulna indicate the placement of large feathers, suggesting that any color patterning would have been clearly displayed on the arms, even if the specific hue remains speculative.
Potential Coloration and Function
Given the lack of direct melanosome evidence, scientists hypothesize Velociraptor’s color scheme based on its environment and biological necessity. V. mongoliensis inhabited the semi-arid, desert environments of the Djadochta Formation in Mongolia, suggesting that camouflage was a significant factor in its survival as a predator.
A sandy, light brown, or reddish-brown coloration, perhaps with disruptive patterns like stripes or spots, would have helped the animal blend into the desert and scrubland terrain. This coloration is common in many desert-dwelling animals, including birds and reptiles, providing the most useful biological analogy. It is also likely the animal exhibited countershading, where the upper surfaces are darker to blend with shadows, and the undersides are lighter to counteract self-shadowing.
Alternatively, the feathered arms may have borne patches of brighter, non-camouflaged colors for communication or sexual display, similar to modern bird courtship displays. Considering its evolutionary relationship with other dromaeosaurs, the coloration was almost certainly a functional and complex pattern, rather than a single, uniform color. Velociraptor was likely a patterned animal designed to blend into the arid landscape, possibly with flashes of color reserved for social interaction.