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, Wisconsin 105.1 males. For every 100 females age 18 and over, there were 110.4 males. The median income for a household in the town was $50,000, and the median income for a family was $54,107. Males had a median income of $33,636 versus $24,671 for females. The per capita income for the town was $19,818. About 5.5% of families and 7.8% of the population were below the poverty line, including 13.0% of those under age 18 and 5.4% of those age 65 or over. Calamus, Wisconsin Calamus is a town in Dodge County, Wisconsin, United States. The population was 1,005 at