@article {7707,
	title = {Incumbency, diversity, and latitudinal gradients},
	journal = {Paleobiology},
	volume = {34},
	number = {2},
	year = {2008},
	note = {PDF},
	pages = {169{\textendash}178},
	keywords = {biogeography, diversification, macroevolution},
	author = {Valentine, James W. and Jablonski, David and Krug, Andrew Z. and Roy, Kaustuv}
}
@article {6708,
	title = {Species{\textendash}genus ratios reflect a global history of diversification and range expansion in marine bivalves},
	journal = {Proceedings of the Royal Society of London. Series B},
	year = {2007},
	note = {PDF},
	pages = {1-7},
	keywords = {biogeography, bivalvia, diversification, macroevolution, mollusca},
	author = {Krug, Andrew Z. and Jablonski, David and Valentine, James W.}
}
@article {6709,
	title = {Contrarian clade confirms the ubiquity of spatial origination patterns in the production of latitudinal diversity gradients},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {104},
	number = {46},
	year = {2007},
	note = {PDF},
	pages = {18129{\textendash}18134},
	keywords = {biogeography, bivalvia, diversification, extinction, macroevolution},
	author = {Krug, Andrew Z. and Jablonski, David and Valentine, James W.}
}
