|2009 Portland GSA Annual Meeting (18-21 October 2009)|
|Paper No. 96-8|
|Presentation Time: 9:00 AM-6:00 PM|
THE RECOGNITION AND IMPLICATIONS OF THE WOOD-BORING TRACE FOSSIL ASTHENOPODICHNIUM XYLOBIOTUM IN UPPER CRETACEOUS STRATA OF GRAND STAIRCASE ESCALANTE NATIONAL MONUMENT, UTAH
MORAN, Kelli L., Physical Sciences, Kutztown, 425 Boehm P.O. Box 730, kutztown, PA 19530, email@example.com, SIMPSON, Edward L., Physical Sciences, Kutztown University of Pennsylvania, 424 Boehm, Kutztown, PA 19530, HILBERT-WOLF, Hannah L., Department of Geology, Carleton College, Northfield, MN 55057, WIZEVICH, Michael C., Department of Physics and Earth Sciences, Central Connecticut State University, 506 Copernicus Hall, 1615 Stanley St, New Britain, CT 06050, GOLDER, Keenan B., Physics and Earth Science, Central Connecticut State University, 1615 Stanley St, New Britain, CT 06050, and TINDALL, Sarah E., Department of Physical Sciences, Kutztown University, P.O. Box 730, Kutztown, PA 19530|
A prolific, macroscopic, wood-boring trace fossil is present in the Late Cretaceous upper and capping sandstone members of the Wahweap Formation and the Kaiparowits Formation in Grand Staircase-Escalante National Monument, Utah. Detailed examination of these borings warrants assignment to Asthenopodichnium xylobiotum (Thenius, 1979). The morphology and paleoenvironmental occurrence of these Asthenopodichnium are discussed and contrasted with the similar wood-boring ichnogenus Teredolites, which is widely considered a marine/estuarine trace fossil.
The scoop-shaped, pouch-like traces occur as ferruginous casts of tree bark and are found throughout both braided and meandering fluvial deposits in the Wahweap and Kaiparowits formations. The long axis of the trace is typically parallel with or sub parallel to the preserved wood grain. The length ranges from 5.0 to 29.0 mm, width from 1.6 to 9.0 mm, and depths from 0.8 to 6.7 mm. Although found as isolated individual traces, they characteristically occur in dense clusters often with superimposed pouches.
Asthenopodichnium differs from Teredolites by: 1) parallel versus perpendicular orientation of the trace elongation direction relative to the wood surface, 2) scoop-like form versus clavate shaped tube, and 3) semi-circle versus circular cross-section. Asthenopodichnium has been attributed to the freshwater boring of mayfly larvae (Ephemeroptera), although amphipods, isopods and dragonflies are also possible producers. Teredolites, a clam boring, is indicative of marine or estuarine deposits, whereas Asthenopodichnium has only been reported in freshwater fluvial deposits. Caution must be exercised in identifying these two distinct borings because of their specific environmental implications.
2009 Portland GSA Annual Meeting (18-21 October 2009)
General Information for this Meeting
|Session No. 96--Booth# 8|
Paleontology: Behavior & Function (Posters)
Oregon Convention Center: Hall A
9:00 AM-6:00 PM, Monday, 19 October 2009
Geological Society of America Abstracts with Programs, Vol. 41, No. 7, p. 262
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