@article {82,
	title = {Heterochrony and phylogenetic trends},
	journal = {Paleobiology},
	volume = {8},
	number = {2},
	year = {1982},
	pages = {130-142},
	author = {McNamara, K.J.}
}
@article {42,
	title = {An echinoderm vitellaria with a bilateral larval skeleton: evidence for the evolution of ophiuroid vitellariae from ophioplutei},
	journal = {Biological Bulletin},
	volume = {163},
	number = {3},
	year = {1982},
	pages = {431{\textendash}437},
	author = {Hendler, G.}
}
