Fig. 5From: Pseudoinversion of septal sutures in Middle Jurassic–Lower Cretaceous non-heteromorph ammonitesa–c Erymnoceras baylei Jeannet with transitional sutural pseudoinversion; Middle Callovian, Coronatum Zone, Alpatyevo, Moscow area, specimen no. PIN 3681/5477; a—ventrolateral view; b—lateral view; c—dorsal view; d, e—Indosphinctes mutatus (Trd.) showing sutural pseudoinversion in the last septated whorl changing from transitional to normal type in last suture. Specimen no. PIN 3665/5477, lateral view; Lower/Middle Callovian transitional beds; Nikitino, Ryazan region, Russia; d—full view; e—last suture lines, enlargedBack to article page