Pennaceous feather Pennaceous feather The pennaceous feather is a type of feather present in most modern birds and in some other species of maniraptoriform dinosaurs. A pennaceous feather has a stalk or quill. Its basal part, called a "calamus", is embedded in the skin. The calamus is hollow and has pith formed from the dry remains of the feather pulp, and the calamus opens below by an "inferior umbilicus" and above by a "superior umbilicus". The stalk above the calamus is a solid "rachis" having an umbilical groove on its underside. Pennaceous feathers have a rachis with "vanes" or "vaxillum " spreading
Calamus Swamp website, Calamus Swamp has a unique plant community. Because of the moist soil, trees such as the American Elm, Green Ash and, in places, Red and Silver maples make up the swamp forest. Calamus Swamp has a wide range of birds and animals: Because the Scioto River is only away, the lake attracts many migrating water birds, such as ducks, geese, grebes, and others. Mammals that have been spotted here include raccoons, muskrats, groundhogs, opossums, and white-tailed deer. The lake is home to other animals including the Ohio fairy shrimp, white leech, horse leech, giant water bug, pond snail, and