The geochronological story of National Park Service paleontology

Tweet, Justin; Santucci, Vincent

The data assembled for the National Park Service’s Paleontology Synthesis Project (PSP) have made it feasible to analyze the geochronological scope of NPS paleontological resources. Paleontological resources have been documented for 283 NPS units and affiliated areas; 245 have confirmed in situ or reworked fossils. From this subset, the NPS record of paleontological resources spans from the Mesoproterozoic to the Quaternary, well over a billion years of Earth’s history. In general, record distribution is related to the recency of a given time division and its duration: more recent divisions are more frequently represented by park fossils than older divisions, and longer divisions are more frequently represented than shorter divisions. Other factors influencing distribution include the presence or absence of organisms with mineralized body structures; the geographic distribution of parks (e.g., there are relatively few large eastern NPS units); and existing knowledge (paleontological work has been more heavily focused on western parks). Dividing time by eras in the Precambrian, periods in the Paleozoic and Mesozoic, and epochs in the Cenozoic, it can be seen that the most frequently represented divisions are the Cretaceous Period (fossils confirmed from 73 NPS units) and the Pleistocene (107) and Holocene (121) epochs. Almost all other divisions are represented by 25–45 NPS units. Park size is a major factor in how many divisions are represented at a given park; the two parks with the most complete records are Death Valley National Park and Denali National Park & Preserve.