Authors: Rudolf Ruedemann
During forty years devoted to collecting and studying graptolites, the writer has observed that their distribution with respect to rock facies and association with other fossils is distinctive. To a far greater extent than any other fossil, the graptolites are bound to one definite rock facies, and they tend to produce pure faunas. They have not been discovered in great numbers mixed with benthonic or nektonic fossils in sandstones and limestones. These two facts-restriction to the black shales and tendency to segregate themselves from other species-have repeatedly impressed themselves upon the writer and have caused him to wonder as to the fundamental meaning…
Published: 11/01/1934
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