Fig. 1

(A) The captured and sampled female Orientocoluber spinalis, from Oeyeon Island, Republic of Korea, with dorsal and ventral scales placed within a conical vial. (B) Microscopic images of the dorsal and ventral scales (designated by red arrows) collected from the fecal sample. (C) Microscopic images of the extracted dorsal scales to exemplify the keel morphology. (D) Magnified photographs of the extracted dorsal scales and of a sub-adult H. vibakari (E) captured on the same island, for comparison