@article {6220,
	title = {The allopatric model and phylogeny in Paleozoic invertebrates},
	journal = {Evolution},
	volume = {25},
	year = {1971},
	note = {PDF},
	pages = {156-167},
	keywords = {biogeography, paleontology, speciation, trilobita},
	author = {Eldredge, Niles}
}
