penniform

Penniform is a term used in the field of entomology to describe the shape of the abdomen in certain insects. The term is derived from the Latin word "penna," meaning feather, and "forma," meaning shape. This term is particularly applied to the abdomen of beetles, where the segments are often elongated and narrow, resembling the shape of a feather or a pen. The penniform abdomen is a characteristic feature of many beetle families, including the Buprestidae (jewel beetles) and the Cerambycidae (longhorn beetles). This shape is thought to serve various functions, such as providing stability during flight or aiding in the storage of food or reproductive materials. The penniform abdomen is a useful taxonomic feature, helping entomologists to identify and classify beetle species.