Abstract Detail

Paleobotanical Section

Boonchai , Nareerat [1], Manchester, Steven [2], Lott, Terry [1].

Southwestern Wyoming Fossil Plants Expedition 2010: retracing petrified wood sites of the1960s-80s.

In 2009, about a hundred Eocene silicified wood specimens with an excellent anatomical preservation were donated to the Paleobotany collection, Florida Museum of Natural History. These specimens were collected during 1966-1984 by James B. Stichka from seven well known lapidary-quality petrified wood localities in southwestern Wyoming. Unfortunately, very little research on wood anatomy in this area has been done to identify the kinds of trees represented. To obtain precise GPS data, relevant geological information, and collect additional specimens, Mr. Stichka, now 94 years old, guided us back to his original collecting sites, successfully retracing his routes in the Eden Valley area of Wyoming from 30-40 years earlier. The localities we collected were Big Sandy Reservoir, Blue Forest, Parnell Draw, and Blue Rim. From the anatomical study of fifty petrified wood samples from the site east of Big Sandy Reservoir (early Eocene Bridger Formation), these stems belonged to Anacardiaceae (Edenoxylon sp.), Lauraceae (Laurinoxylon sp.), another undetermined dicotyledonous wood, and Palmae (Palmoxylon sp). The diversity of trees from this site is low, dominated by anacardiaceous wood and palm. We are still investigating the taxonomic affinities of wood from other sites. In addition, other plant organs and animal fossils have been found at these sites, e.g., leaves of Lygodium, Populus, and fruits of Landeenia. These fossil wood specimens provide another opportunity to augment the floristic composition and paleoclimate of the Eocene floras from southwestern Wyoming, which is generally in agreement with other fossil evidence from the Early Eocene in this region. The dicotyledonous woods recovered so far are diffuse porous and semi-ring porous, suggesting moderate seasonality. These wood taxa imply that the paleoclimate was subtropical rather than the semi-arid conditions that are present today.

Broader Impacts:

1 - Florida Museum of Natural History, Natural History, Museum Rd & Newell Dr, University of Florida, Gainesville, FL, 32611, USA
2 - University of Florida, Florida Museum of Natural History, PO Box 117800, Gainesville, FL, 32611, USA

Keywords:
Petrified wood
Eocene
expedition
southwestern Wyoming.

Presentation Type: Oral Paper:Papers for Sections
Session: 12
Location: Lindell C/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 1:45 PM
Number: 12002
Abstract ID:287