Amber encyclopedia entry #4: Feather in burmese amber

Double Rachis Feather in Burmese Amber – Cretaceous Inclusion

This striking 10-gram piece of Burmese amber, estimated to be around 99 million years old, contains an exceptionally rare feather inclusion featuring a double rachis — a condition where two central shafts run parallel through the same feather. This bifurcated structure is considered highly unusual, with potential implications for understanding the evolution of feathers in early birds or feathered dinosaurs.

Unlike the typical feather with a single central shaft, this specimen shows two distinct rachises diverging from a shared base. Under magnification, the barbs on each shaft are neatly aligned and display exquisite detail, with clear segmentation and symmetry.

🔬 Key Features:

Double rachis structure – two parallel feather shafts visible from base to tip

Carbonized pigmentation – dark preservation along the central shafts

Detailed barbs and barbules – intact and clearly separated from each rachis

Exceptional clarity – preserved in warm golden Burmese amber, with minimal distortion

This piece offers an exceptional window into the biology of the Cretaceous period and may represent an early aerodynamic adaptation or structural specialization, possibly for display or thermoregulation.

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🧬 Scientific Context

Age: ~99 million years (Late Cretaceous, Cenomanian)

Origin: Hukawng Valley, Kachin State, Myanmar

Inclusion Type: Feather (possible avialan or coelurosaurian origin)

Notable Trait: Rare bifurcated midline (double rachis morphology)

Scientific Relevance: Contributes to studies on feather diversity and evolution in the Mesozoic

See related:

Are feathers in amber from dinosaurs?

https://www.amberbugs.com/post/the-beautiful-mystery-of-feathers-in-amber