1. Department of Mineralogy; Natural History Museum; Cromwell Road; London; SW7 5BD; UK
2. Glasgow Experimental MRI Centre; Wellcome Surgical Institute, University of Glasgow; Glasgow; G61 1QH; UK
3. DipTeRis; University of Genoa; Viale Benedetto XV 5; Genoa; I-16132; Italy
4. Department of Zoology; Natural History Museum; Cromwell Road; London; SW7 58D; UK
5. Department of Biology and Biochemistry; University of Bath; Bath; BA2 7AY; UK
6. Nikon Metrology; Icknield Way; Tring; Hertfordshire; HP23 4JX; UK
7. Department of Surgery and Cancer; Imperial College; London; W6 8RF; UK
8. Department of Chemistry; University of Bath; Bath; BA2 7AY; UK