Grand Canyon National Park Centennial Paleontological Resources Inventory

Vincent Santucci, Justin Tweet — Tue, 06 Apr 2021 00:00:00 -0600

On an otherwise unremarkable fall day in 2017, National Park Service Senior Paleontologist Vincent Santucci made an astonishing proposal: he offered to lead a comprehensive paleontological inventory of Grand Canyon National Park. Astonishing, in that such a survey had not yet been accomplished at what is arguably the world’s most geologically iconic national park and that the timing could not have been better. We were preparing to celebrate the 2019 Centennial of Grand Canyon National Park; the first complete paleontological park inventory would be a highlight of the celebration.

This proposal kicked off a whirlwind of activity and collaboration that resulted in a year-long effort by a world-class team of multi-disciplinary geologists and paleontologists to research, investigate, and ground-truth the astonishing array of fossils up to 1.25 billion years old that are exposed in the canyon. This adventure included the first-ever PaleoBlitz at a national park in October 2019, development of a popular set of paleontology trading cards, presentations during the Grand Canyon National Park Paleontology Symposium, and hosting of the tenth anniversary of National Fossil Day. The culmination of this extensive work was the publication of a volume presenting the remarkable history of life and its evolution as uniquely exposed in GRCA. Out of this effort would come an improved understanding of ancient environments, extinction events, the discovery of new life forms, and a catalogue of ancient life.

Lead Paleontologist Vince Santucci sets the context for this study, the impetus for the largest effort of its kind by the NPS, and the critical work behind the scenes. Dr. Earl Spammer provides an evocative and fascinating account of the 160-year history of fossil exploration at the canyon. The following paleontology inventory chapters are organized chronologically, by stratigraphic strata, and taxonomically, characterizing trace fossils, invertebrates, vertebrates, and plants found in the predominantly Precambrian to Paleozoic rocks of the Grand Canyon. Several of the life forms presented by these authors were newly discovered during the week-long PaleoBlitz held at the canyon.

A series of experts presents the inventory of life in the canyon’s fossil record, from the very earliest life forms starting around 1.25 billion years ago in the Precambrian era (stromatolites and microfossils), through explosions of ancient life, punctuated by extinction events, in the Paleozoic era from the Cambrian (~541–485 million years ago) up into the Permian (~270 million years ago), as seen by the diversity of fossils (trilobites, brachiopods, mollusks, corals, fish, sharks, horsetails, seed ferns, clubmosses, conifers) preserved in these rocks. This variety of ancient life was abruptly cut off in the late Permian by earth’s most catastrophic extinction event, which was followed by the slow recovery of life between approximately 252 and 215 million years ago in the early Mesozoic era, barely represented in the youngest GRCA rocks by fossil logs and reptilian trackways. A separate chapter presents the much more recent lifeforms of the Ice Age (Pleistocene and Holocene), represented by fossils (extinct mountain goats, ground sloths, tortoises, packrats, camels) found in GRCA’s caves. Finally, the inventory is capped by a section outlining appropriate paleontological resource inventory, monitoring, and protection efforts, with recommendations for outreach, education, and stewardship of these unique treasures.

During these hectic times, it is important to contemplate the long history of life, punctuated by massive extinction events, to imagine ancient worlds with exotic climates, and to ponder what lifeforms are yet to be discovered in these rich environments exposed so uniquely at Grand Canyon. This volume will reward you with the opportunity to celebrate the wonderous diversity of plants, animals, and environments that have inhabited this now iconic setting, and invite you to explore the complete inventory more deeply, and perhaps even add to it.

Utah Geological Association Special Publications

Grand Canyon National Park Centennial Paleontological Resources Inventory