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 Creek Bridge Calamus Creek Bridge The Calamus Creek Bridge near Maxwell, Iowa is a concrete Luten arch bridge that was built in 1905. At a cost of $900, it was built by N.M. Stark and Company, a firm which built several Luten arch bridges that are listed on the National Register of Historic Places (NRHP). The Calamus Creek Bridge was listed in 1998. It has a single span and a total length of . The NRHP nomination for the bridge asserts:Before the codification of bridge design in the state in 1913, Stark built perhaps hundreds of Luten arches throughout Iowa, in exclusive