A response to Ziegler A, Faber C, Mueller S, Bartolomaeus T: Systematic comparison and reconstruction of sea urchin (Echinoidea) internal anatomy: a novel approach using magnetic resonance imaging. BMC Biol 2008, 6: 33. © 2009 Holland and Ghiselin; licensee BioMed Central Ltd.
Holland, N. D., & Ghiselin, M. T. (2009, July 13). Magnetic resonance imaging (MRI) has failed to distinguish between smaller gut regions and larger haemal sinuses in sea urchins (Echinodermata: Echinoidea). BMC Biology. https://doi.org/10.1186/1741-7007-7-39