Kellner , A. W. A., T. R. Simões, D. Riff, O. Grillo, P. Romano, H. de Paula, R. Ramos, M. Carvalho, J. Sayão, G. Oliveira, and T. Rodrigues. “The Oldest Plesiosaur (Reptilia, Sauropterygia) from Antarctica”. Polar Research, June 2011, doi:10.3402/polar.v30i0.7265.