| Light brown densely hard keratinous material was present in the center of the lesions. |
| Additionally, keratinous deposits and cysts may be present within these tumors. |
| The lesion begins as a condylomatous lesion which eventually ulcerates and develops sinuses that exhibit foul-smelling keratinous material. |
| The wing spurs are keratinous structures that grow anteriorly from the carpal-metacarpal joints. |
| Strictly, the exoskeleton is restricted to keratinous elements such as horns, nails, claws, hairs, feathers, etc. |
| Spadefoots are so-named for the large, keratinous metatarsal tubercles that are internally supported by a well-ossified prehallux, located on the outside edges of their feet. |
