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 Swamp the blood sucking leech. Calamus Swamp Calamus Swamp is a public preserve located from Circleville in Pickaway County, Ohio, United States. It has a natural kettle lake/wetland and is owned by the Columbus Audubon, the local chapter of Audubon. Calamus Swamp includes the only known kettle lake in Central Ohio that is naturally vegetated and undisturbed. The kettle lake was made in the last ice age by the glacier that covered 2/3 of Ohio. When Ada May Burke and Sally V. May got the land, they donated it to Columbus Audubon, who then made it into a public preserve. According