Abstract Detail

Paleobotanical Section

Bronson, Allison [1], Maisey, John [2], Tomescu, Alexandru M.F. [3].

Reconstructing ancient Mississippian coastal habitats and depositional environments based on flora and fauna: an integrative approach.

Integrative studies utilizing paleobotanical, paleontological, and sedimentological information can provide more detailed and comprehensive answers to existing questions about ancient environments and communities. In the Mississippian of North America, three fossiliferous occurrences contain abundant, well-preserved floras and faunas (fish and invertebrates): Bear Gulch (318 Ma, Serpukhovian, Montana), the Illinois Basin (Tournaisian-Serpukhovian), and the Fayetteville Shale (354–323 Ma, Tournaisian-Serpukhovian, Arkansas). Together, these deposits provide an excellent opportunity for reconstructing paleoenvironments, comparing ancient climatic conditions along latitudinal gradients, and seeking connections between environment and organismal diversity. Each of these American localities represents an aquatic environment preserving macroinvertebrates, cartilaginous fishes, and terrestrial or aquatic plants/algae preserved both by permineralization and as compressions. Bear Gulch provides exceptional preservation of fish fossils and a complex algal assemblage, while the Fayetteville Shale hosts abundant allochthonous land plant assemblages accompanying a rich array of chondrichthyans (cartilaginous fishes). Inclusion of a third set of fossil assemblages, the Illinois Basin, incorporates permineralized land plants as well as bony fishes and invertebrates, providing terms for comparisons addressing questions of ecosystem-level diversity. Each of these three marine fossiliferous occurrences provides different information in the form of varying fossil diversity, as well as in the depositional environment. Bear Gulch, for example, likely represents a shallow marine lagoon. The Illinois Basin is marine, but transitions to a swampy environment at the beginning of the Pennsylvanian, while the Fayetteville Shale represents both estuarine and shallow nearshore habitats. We compare the floras and faunas of these three Mississippian localities and use this information to draw conclusions about environmental effects on each of these unique marine environments. Because biotic factors may be correlated with the success of extinct evolutionary “side-branches” in plant and animal groups, we anticipate that extensive data on Carboniferous plants will impact our understanding of chondrichthyan evolutionary trajectories.

1 - American Museum of Natural History, Richard Gilder Graduate School, Central Park West at 79th Street, New York, NY, 10024, USA
2 - American Museum of Natural History, Division of Paleontology, Central Park West at 79th Street, New York, NY, 10024, USA
3 - Humboldt State University, Department of Biological Sciences, 1 Harpst Street, Arcata, California, 95521, USA

Keywords:
Mississippian
paleoenvironment
land plants
algae
fish.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PPB007
Abstract ID:578
Candidate for Awards:None