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 (DTP) use optical kerning, where the shapes of the characters are analysed to determine the appropriate distances; Calamus’ approach might be regarded as a simplification of that, working with a low-resolution version of the final character. Calamus (DTP) Calamus is a desktop publishing application, built for the Atari ST computer. The first version was released on July 1, 1987 by the former German software company DMC GmbH. Calamus is still supported by its German owner company, invers Software, and also runs under a built-in and transparent Atari emulator on Windows, or on other platforms such as Mac OS 9 and Mac