Sites of cell proliferation during scute morphogenesis in turtle and alligator are different from those of lepidosaurian scales

Cell proliferation in forming shield scutes has been studied by immunofluorescence in embryos of turtle, alligator and snake after injection of 5‐bromo‐deoxy‐uridine. Hinge regions of scutes in alligator and turtle carapace derive from an initial waving and invagination of the epidermis that contains 5‐bromo‐deoxy‐uridine‐labelled cells. This suggests that down growth of the epidermis into the dermis is driven by local proliferation in addition...