A fossil protein chimera; difficulties in discriminating dinosaur peptide sequences from modern cross-contamination Author Michael Buckley Faculty of Science and Engineering, The University of Manchester, Manchester Institute of Biotechnology, Manchester M 1 7 DN, UK School of Earth and Environmental Sciences, Faculty of Science and Engineering, Interdisciplinary Centre for Ancient Life, The University of Manchester, Manchester, M 13 9 PL, UK Author Stacey Warwood Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Manchester M 13 9 PL, UK Author Bart van Dongen School of Earth and Environmental Sciences, Faculty of Science and Engineering, Interdisciplinary Centre for Ancient Life, The University of Manchester, Manchester, M 13 9 PL, UK Author Andrew C. Kitchener Department of Natural Sciences, National Museums Scotland, Chambers Street, Edinburgh EH 1 1 JF, UK Institute of Geography, School of Geosciences, University of Edinburgh, Drummond Street, Edinburgh EH 8 9 XP, UK Author Phillip L. Manning School of Earth and Environmental Sciences, Faculty of Science and Engineering, Interdisciplinary Centre for Ancient Life, The University of Manchester, Manchester, M 13 9 PL, UK Department of Geology and Environmental Geosciences, College of Charleston, 66 George Street, Charleston, SC 29424, USA text Proceedings of the Royal Society, Series B 2017 284 544 544 journal article 23022 10.1098/rspb.2017.0544 c6997856-1dd8-4f2a-8207-b0605f3e4392 PMC5454271 28566488 3748698

Table 1. Peptide matches to Brachylophosaurus collagen from Schweitzer et al. [14] and the taxa they can be found in as originally stated (with added observations by BLAST search in parentheses, with an emphasis on the potential contaminants). Underlined residues indicate post-translational modification (oxidation of P; deamidation of N).

peptide sequence	protein	taxa
*Note that this amino acid sequence (bold) was ‘corrected̍ from the T. rex sequence originally proposed by Asara et al. [5]. a This part of the sequence is not currently complete for ostrich (Struthio) by BLAST search.
*Note that these were the two peptides observed in both analyses [5].
GLTGPIGPPGPAGAPGDKGEAGPSGPPGPTGAR	COL1A1	ostrich and mammals
GSAGPPGATGFPGAAGR	COL1A1	Tyrannosaurus rex, chicken and mammals (and others, including alligator a)
GATGAPGIAGAPGFPGAR	COL1A1	Tyrannosaurus rex, chicken, alligator and amphibians (and other reptiles and birds)
GETGPAGPAGPPGPAGAR	COL1A1	chicken (and other birds, including ostrich)
GVQGPPGPQGPR	COL1A1	Tyrannosaurus rex, chicken, alligator and opossum (and others, including ostrich)
GPSGPQGPSGAPGPK	COL1A1	chicken, alligator, rat and opossum (and others, including ostrich)
GSNGEPGSAGPPGPAGLR	COL1A2	chicken and alligator (and other birds, including ostrich)
GLPGESGAVGPAGPP•GSR	COL1A2	Tyrannosaurus rex
*GSAGPPGATGFPGAAGR	COL1A1	Tyrannosaurus rex, chicken, mammals (and others, including alligator)
*GATGAPGIAGAPGFPGAR	COL1A1	Tyrannosaurus rex, chicken, alligator and amphibians (and other reptiles and birds)
GFPGADGIAGPK (GFPGADGIsGPK)	COL1A1	ostrich and others (*alligator)
GFPGLPGPSGEPGK	COL1A1	alligator and ostrich (and others, ranging from fish to mammals)
GQAGVMGFPGPK	COL1A1	alligator and ostrich (and others)
EGPVGFPGADGR	COL1A2	alligator and ostrich (and others, including reptiles, birds and mammals)
GATGLPGVAGAPGLPGPR	COL1A2	alligator (and rodents)
GEPGNIGFPGPK	COL1A2	alligator and ostrich (and others, including birds and mammals)