Fig. 1. Radiographs of the naked mole-rats. (A) Relative sizes of mole-rats examined in the study. All images are aligned at the base of the L8 vertebra (broken line). The solid white line is aligned to the top of the lumbar spinal column (anterior aspect of L1) in the breeding female (02-04). Only the established breeding female has a comparably long lumbar spinal column. (B) Diagram showing the width across the zygomatic arch (white line) and the labeling scheme for the lumbar vertebra, with L4 marked with an asterisk. (C) Two images of the same female mole-rat taken at the beginning and end of the study. (D) An image of a late-stage pregnant mole-rat. Scale bar for all panels=2 cm.