@article {7543,
	title = {Approximate evolutionary stasis for bivalve morphology over millions of years: a multivariate, multilineage study},
	journal = {Paleobiology},
	volume = {13},
	number = {2},
	year = {1987},
	note = {PDF},
	pages = {113-139},
	keywords = {bivalvia, evolution, fossils, mollusca, paleontology},
	author = {Stanley, Steven M. and Yang, Xiangning}
}
