Type I collagen is a member of group I collagen (fibrillar forming collagen). Trimers of one alpha 2(I) and two alpha 1(I) chains. Proline residues at the third position of the tripeptide repeating unit (G-X-Y) are hydroxylated in some or all of the chains. These protein fragments were extracted from an 80-million-year-old fossil. The tryptic peptides required multiple purification steps in order to eliminate contaminants and to increase the concentration of peptidic material. Belongs to the fibrillar collagen family.