Sinornithosaurus form from those found on birds from the same geological deposits. The body (contour) feathers were generally between 3-4.5 cm long and included two types: the first type are formed of several filaments joined together into "tufts", similar to modern down feathers. The second type, including those on the arms, were composed of rows of filaments ("barbs") joined together along a main shaft ("rachis"), making them similar in structure to modern bird feathers. However, unlike the wing feathers of flying birds, they did not have the secondary branches with tiny little hooks ("barbules") that flight feathers have, which allow the
What Bird is That? What Bird is That? What Bird is That? A Guide to the Birds of Australia is a book first published in 1931 by Angus & Robertson in Sydney. Authored and illustrated by Neville William Cayley, it was Australia’s first fully illustrated national field guide to birds, a function it served alone for nearly 40 years. In 1960 it was rated the all-time best seller in Australian natural history. "What Bird Is That?" was originally published in octavo format (239 x 158 mm), containing 340 pages bound in green buckram, with a dust jacket illustrated with a painting of a laughing