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
Calamus, Iowa located in Wheatland, Iowa. The school is part of the Calamus-Wheatland Community School District, and has an enrollment of approximately 120 students in grades nine through 12. http://www.cal-wheat.k12.ia.us/ Calamus has 4 county parks: Calamus, Iowa Calamus is a small town in Clinton County, Iowa, United States located on the historical Lincoln Highway, which was the first transcontinental highway for automobiles across the U.S.. Calamus is the only town in Olive Township and had a population of 439 at the 2010 census, which was an 11.4% increase from the 2000 census. Calamus was named after Calamus creek, which received its name