Fig. 4. Microdrile oligochaete PIN 5640 in A probable oligochaete from an Early Triassic Lagerstätte of the southern Cis-Urals and its evolutionary implications

Fig. 4. Microdrile oligochaete PIN 5640/212 (A) from the Petropavlovka Formation, Olenekian (Lower Triassic), Petropavlovka III section, Russia and extant Tubifex tubifex (Müller, 1774) (B) from the Khripan' River, Moscow region, Russia. A. Oblique view of posterior end emphasizing body wall layering (arrowed), prominent raised annuli and finer annulets (A1). Detail of body wall layers (А2). B. Body wall layers (arrowed; B1, B2).