Figure 4 : Identification of D-glucosamine as the final step in supporting the presence of chitin in the fossil V. gracilenta.

From: Discovery of 505-million-year old chitin in the basal demosponge Vauxia gracilenta

Figure 4

HPCE chromatograms as well as ESI-MS results give unambiguous evidence that D-glucosamine is present in the investigated samples (b) when compared with results from a chitin standard (a).