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 Creek (Wisconsin) Calamus Creek (Wisconsin) Calamus Creek is a minor tributary of the Beaver Dam River, about long, in southeastern Wisconsin in the United States. Via the Beaver Dam, Crawfish, and Rock rivers, it is part of the watershed of the Mississippi River. Its watershed lies almost entirely within Dodge County with a small portion in neighboring Columbia County. Calamus Creek rises in west central Dodge County near the intersection of Mt. Pleasant and Van Buren roads and follows a highly winding, generally easterly course through Dodge County. It flows into the Beaver Dam River about southwest of Beaver Dam, near the