S1. Iconography of the sources, other than Seba and Ray, cited by Linnaeus (1758) in the description of Elephas maximus.
Figure S1.1. Gesner, C. 1551. Historiae Animalium Lib. 1 de quadrupedibus viviparis. , 1104.  pp. Froschover, Zurich.
Figure S1.2. Aldrovandi, U. 1616. De quadrupedibus solidipedibus volumen integrum. 495 pp. Bologna.
Figure S1.3. Jonston, J. 1650. Historiae naturalis de quadrupedibus liber 1. De quadrupedibus Solipedibus. 231 pp., 80 pls. Marianus, Frankfurt.
S2. Albertus Seba, his collection and the fate of his elephant foetus.
S3. Ancient protein sequencing and identification of genus-diagnostic peptides: materials and methods.
Figure S3.1. Tandem spectrum, generated by nanoLC-MS/MS analysis of the ancient foetus sample, supporting identification of the L. africana version of the genus-diagnostic tryptic peptide E86AALVDVV93NDGVEDLR101.
Figure S3.2. Tandem spectrum, generated from the analysis of the Seba elephant sample, supporting identification of the L. africana version of the genus-diagnostic tryptic peptide L627YLI630NSPVVR636.
Figure S3.3. Tandem spectrum, generated from the analysis of the Seba elephant sample, supporting identification of the L. africana version of the genus-diagnostic tryptic peptide N184M185MFQVLAAEEPTVR198.
Figure S3.4. Tandem spectrum, generated from the analysis of the Seba elephant sample, supporting identification of the L. africana version of the genus-diagnostic tryptic peptide V202APLQGV208LPSLLAPLR217.
Table S3.1. Protein recoveries, before and after digestion, for each of the two Seba foetus extracted samples.
Table S3.2. Statistics for MaxQuant MS/MS spectra matching against the Loxodonta africana reference proteome.
Table S3.3. Statistics for MaxQuant MS/MS spectrometry spectra matching against the Elephas maximus complete protein list.
Table S3.4. Primer sets used to amplify Loxodonta/Elephas DNA regions coding for genus-diagnostic peptides.
Table S3.5. Variable and diagnostic sites across geographically diverse Asian, African forest and African savannah elephants.
Table S3.6. Primers used to amplify Loxodonta/Elephas diagnostic sites in mitochondrial DNA.
Table S3.7. PCR primers and M13 tails used in this study to attempt amplification of nuclear nucleotide sites diagnostic between African forest and African savannah elephants (Ishida et al., 2011).
Table S3.8. Evidence supporting the identities of proteins bearing genus-diagnostic tryptic peptides.
Table S3.9. Clade-informative sites overlapping mtDNA sequences generated for the Seba elephant foetus.
S4. John Ray and his tour across part of Europe.
S5. Translation of Ray's Latin text mentioning the elephant he observed in Florence.
S6. Reconstruction of the fate of the Florence elephant.
Table S6.1. Inventory numbers documenting the presence of the elephant skeleton observed by John Ray in the Florence Royal Museum since the end of the 18th century.
Table S6.2. Comparison of the measures of the elephant skeleton reported by Targioni Tozzetti (1763) and those of specimen 734 as measurable today.
S7. Possible identification of the Florence elephant as the performing itinerant elephant known as ‘Hansken’.
Figure S7.1. Rembrandt, An elephant, 1637 (drawing). Vienna, Albertina.
S8. Another extant syntype specimen of Elephas maximus: a partial elephant tooth in Uppsala.
Figure S8.1. Elephas maximus molar fragment (catalogue number UUZM 370) in the Uppsala University Zoological Museum collection.