Specimens of Archaeopteryx The end of the feather has an obtuse angle of 110°, while the barbs branch off from the rachis at an angle of around 25°. The barbs branch noticeably into barbules, as in the feathers of modern birds. The base of the feather consists of plumulaceous barbs which are unconnected to one another and result in a down-like appearance. This tuft of down led Griffiths to conclude that "Archaeopteryx" might have been endothermic in that it implies the use of thermal insulation. The feather is clearly asymmetrical, which has been interpreted by many scientists to be a clear indication of
Calamus rotang plants. It has pinnate, alternate leaves, 60–80 cm long, armed with two rows of spines on the upper face. The plants are dioecious, and flowers are clustered in attractive inflorescences, enclosed by spiny spathes. The edible fruits are top-shaped, covered in shiny, reddish-brown imbricate scales, and exude an astringent red resin known medicinally and commercially as "Dragon's blood". The canes are sought-after and expensive, but have to a large extent been replaced by sticks made from plants, such as bamboos, rushes and osier willows. Calamus rotang Calamus rotang is a plant species native to India, Sri Lanka and Myanmar (Burma).