The Paleobiology Period
By the late 1960’s it was recognized, through a number of seminal works, that invertebrate fossils were distributed through the rock record not only with respect to time but also to space. The recognition that certain genera and species recurred within certain rock types (lithologies) led researchers to the initiation of the field of paleoecology. It is the concept that fossils lived in biologic communities and were captured in time in the rock record. This in turn led to the creation of the sub-discipline that is part biology and part geology known as paleobiology.

Like paleontology before it, the new field of paleobiology exhibited growth stages. The 1970’s can be called the "paleoecology stage." During this time, much of the literature dealt with the ecology of ancient communities and how they were distributed through time and space. By the 1980’s the emphasis had switched to major extinction events and how the Earth's biosphere evolved in relation to these catastrophic biotic periods. In the 1990’s the science moved toward recognition of major evolutionary events, and the relationships between ecology, biogeography, and evolutionary tempo.

Although early paleobiologists developed elaborate theories based on Treatise information, basic paleontology continued to describe new species and update ranges of taxa during the 1960’s to 1990’s. Thus, many of the early paleobiologic hypotheses are replete with erroneous assumptions, because the authors relied solely on outdated Treatise information and had failed to incorporate new taxonomic material. So overwhelming was this new information that an updated Treatise had to be published in multiple volumes.