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) with drumlins and scattered muck deposits. Soils are predominantly well drained silt over calcareous sandy loam till." The original vegetation cover is primarily white oak, black oak, bur oak, marsh and sedge meadow, wet prairie, and lowland shrubs. Calamus Creek is part of the larger Upper Rock River Basin. The of the streams comprising the Calamus Creek watershed cover , or 19315 acres, with 54.39 acres covered by five unnamed lakes and 3627.39 acres of wetlands. The watershed includes extensive wetlands, some of which are in the process of restoration. Parts of Calamus Creek are designated wadable nursery waters for