Talk:Sea Urchin Development
From Embryology
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2842880/?tool=pmcentrez
http://www3.interscience.wiley.com/journal/122539485/abstract?CRETRY=1&SRETRY=0
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2842880/pdf/nihms181964.pdf
Sand dollar http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0009654