The objective of this dissertation is to write the first pages of the biography of paleobiological data. I will focus on i) the genesis of this kind of data as it emerged in German stratigraphy and paleontology between the mid 19th and the early 20th centuries and ii) how the conceptualization of the paleontological data was reformulated and taken as the starting point for studying the patterns of the diversity of life in deep time between the 1940s and 70s. This is the turning point that marks the ‘coming into being’ of specifically paleobiological data. I will reconstruct in detail how it was possible to transform an incomplete and misleading material object — the fossil record that can be admired in a museum —into a no longer misleading source of knowledge. I will namely describe the genesis of the paleobiological practice by retracing the encounter of two different approaches to the fossil record between the mid 19th and early 20th centuries in German academia and their later diffusion into English-speaking countries.