Ehrlich, H., Rigby, J. K., Botting, J. P., Tsurkan, M. V., Werner, C., Schwille, P., Petrasek, Z., Pisera, A., Simon, P.,
Sivkov, V. N., Vyalikh, D. V., Molodtsov, S. L., Kurek, D., Kammer, M., Hunoldt, S., Born, R., Stawski, D., Steinhof, A.,
Bazhenov, V. V., & Geisler, T. (2013). Discovery of 505-million-year old chitin
in the basal demosponge Vauxia gracilenta. Scientific Reports, 3:.
doi:10.1038/srep03497.