In some annelids, including earthworms, all respiration is via the skin. However, many polychaetes and some clitellates (the group to which earthworms belong) have gills associated with most segments, often as extensions of the parapodia in…
The Rotzo Formation (also known in older literature as the Noriglio Grey Limestone Formation) is a geological formation in Italy, dating to roughly between 192 and 186 million years ago and covering the Pliensbachian stage of the Jurassic…
A median, segmented, annelid nerve cord has repeatedly been compared to the arthropod and vertebrate nerve cords and became the most used textbook representation of the annelid nervous system.