Pleistocene Park, and other designs on deep time in the Interwar United States

Precisely how to reconstruct the planetary past is not predetermined. This article compares three contemporary plans, dreamed up in the United States during the Interwar and Depression years, that deploy diverse techniques to evoke extinct environments. Building on Martin Rudwick's historicization of ‘scenes from deep time’, this article develops the concept of designs on deep time to explain how public displays of the planetary past circulate anything-but-neutral ideas about past and present to awed audiences. By detailing three contemporary designs on deep time—Pleistocene Park at the La Brea Tar Pits, a sensational World's Fair exhibit called ‘The World a Million Years Ago’, and a dinosaur park where living fossils and ancient plants approximated a Mesozoic atmosphere—this article captures diverse philosophies about how to construct persuasive encounters with the prehistoric past. It also demonstrates how, despite disparate approaches, these designers of deep time displays all used the planetary past to legitimate present regimes and foster faith in human progress. During the 1920s and 1930s, when the wounds of war, changing demographics, and economic depression collaborated to dispute a prevailing myth of American progress, deep time by design buoyed faith in a better future.

Differential taphonomic effects of petroleum seeps and karstic sinkholes on ancient dire wolf teeth: Hydrocarbon impregnation preserves fossils for chemical and histological analysis

ABSTRACTHistological analysis of teeth can yield information on an organism’s growth and development, facilitating investigations of diet, health, environment, and long-term responses to selective pressures. In the Americas, an extraordinary abundance of Late Pleistocene fossils including teeth has been preserved in petroleum seeps, constituting a major source of information about biotic changes and adaptations at the end of the last glacial period. However, the usefulness of these fossils for histological studies is unclear, due to the unknown taphonomic effects of long-term deposition in petroleum. Here, we compare histological and chemical analyses on dire wolf (Canis dirus) teeth obtained from two different environments, i.e. a petroleum seep (Rancho La Brea tar pits, California) and a carstic sinkhole (Cutler Hammock sinkhole, Florida). Optical and scanning electron microscopy (SEM) together with X-ray diffraction (XRD) analysis revealed excellent preservation of dental microstructure in the seep sample, and the petroleum-induced discoloration was found not to interfere with the histological and chemical examination. By comparison, teeth from the sinkhole sample showed severe degradation and contamination of the dentine by exogenous substances. These results indicate that petroleum seep assemblages are useful, or even ideal, environments for preserving the integrity of fossil material for chemical and histological analysis.

Leveraging Collective Experience to Digitize the Fossil Insects of Los Angeles

The Invertebrate Paleontology Collection at the Natural History Museum of Los Angeles County (NHMLA) has received support from the United States National Science Foundation (NSF DBI 1702342) to digitize the museum’s unique and historic collection of 28,000+ fossil insects. The primary goal of this project, “Fossil Insects of L.A.”, is to increase access to these collections for both research and education. Key collections to be become discoverable through iDigBio and iDigPaleo include the Georg Statz Collection (Oligocene, Rott Formation, Germany) and three faunas from Southern California: Barstow (Miocene), Rancho La Brea (Pleistocene), and McKittrick (Pleistocene). Fossil Insects of L.A. constitutes the final contribution to the Fossil Insect Collaborative Thematic Collections Network (TCN), a consortium of institutions that have been digitizing the largest fossil insect collections in the United States. As a project beginning at the tail-end of the TCN’s active funding, Fossil Insects of L.A. is actively leveraging existing TCN knowledge and resources to streamline workflows and efficiently achieve project goals. In addition to basing imaging and preservation protocols on those designed by TCN partners, Fossil Insects of L.A. is using a layered approach to provide high-quality taxonomic information without sacrificing the pace of specimen digitization. Previously unidentified specimens are initially identified only to Order, allowing them to quickly continue through the digitization process; specimens can then be re-examined by experienced project participants and external experts, who are able to reference the specimen images generated during digitization. A critical and novel aspect of this component of the project’s workflow is the concurrent digitization of the literature associated with the Statz Collection. These data will be used as a test case for the "Enhancing Paleontological and Neontological Data Discovery API" (ePANDDA) project (NSF ICER 1821039), which seeks to associate related datasets found in iDigBio, iDigPaleo, and the Paleobiology Database. Fossil Insects of L.A. will digitize and make 10,960 specimens publically available online, of which over 6,200 will include images. An additional 15,684 specimen records from the Rancho La Brea Tar Pits will also be included in the data mobilization. In doing so, Fossil Insects of L.A. intends to dramatically enhance the research potential of these formerly hidden collections, as well as synthesize and demonstrate digitization best practices generated through the TCN.