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26th Midcontinental Paleobotanical Colloquium March 13-15, 2009 East Tennessee State University, Johnson City, Tennessee Home | Program | Registration | Field Trip | Abstracts | Lodging | Travel to Johnson City |
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Author index |
ABSTRACTS A new Neocalamites from the Triassic of China Brian Axsmith (University of South Alabama) Multidisciplinary Research at Höwenegg, Hegau, Germany (Late Miocene, Early Vallesian, MN9, 10.3 Ma) Raymond L. Bernor1, 2, 3 , Hans-Walter Mittmann3 , Wolfgang Munk3 and Dominik Wolf 1 1 College of Medicine, Department of Anatomy, Laboratory of Evolutionary Biology, Howard University, Washington D.C. 2 Sedimentary Geology and Paleobiology Program, National Science Foundation, Arlington, Virginia 3 Staatliches Museum für Naturkunde, Karlsruhe, Germany Summary Fossil vertebrates were first discovered at Höwenegg at the beginning of the 20th century, and the main site itself was discovered in 1936. It is renowned for its preservation of complete mammalian skeletons, including a number of females with fetuses in situs utero. The tridactyl horse Hippotherium primigenium, the archaic boselaphine antelope Miotragocerus pannoniae, and the rhinoceros, Aceratherium incisivum are all known from multiple skeletons, and a muntiak deer and a tragulid species are represented by partial skeletons. Small mammals are also represented by complete skeletons (Prolagus oeningensis; Tobien, 1986), and with the successes of our project, new tooth specimens. Extensive, but episodic quarrying was undertaken between 1950 and 1963 under the joint direction of Professors Heinz Tobien (then, Darmstadt) and Erwin Jörg (Karlsruhe). A summary of Höwenegg’s geology and paleontology was published by Tobien (1986), while descriptions of Höwenegg’s stratigraphy, sedimentology and taphonomic context (Jörg and Rothausen, 1991; Woodburne et al., 1996), turtles (Schleich, 1986), carnivores (Beaumont, 1986), rhinoceroses (Hünermann, 1982), chalicotheres (Zapfe, 1989) and hipparionine horses (Bernor et al., 1997) have also been published. The age of the Höwenegg fossil accumulation has been securely established as being 10.3 Ma (Swisher, 1996), or slightly younger than this age. It is correlative with European Mammal Neogene Unit 9 (MN 9) and it has the potential for becoming an important paleobiological standard for the early late Miocene. Until June, 2003 there had been no fossil excavations undertaken at Höwenegg since 1965. Yet, there were many outstanding, unresolved issues about the Höwenegg site, including further refinement of its actual chronometric age, the sedimentologic and taphonomic regimes under which the vertebrate skeletons were accumulated, and a complete, integrated reconstruction of Höwenegg’s paleoenvironmental context. These are all attainble goals and should be realized given sufficient time and resources to undertake excavations at the site. Also, there was the strong belief that further skeletons could be unearthed at Höwenegg. In order to address these outstanding issues, and to develop Höwenegg as the late Miocene vertebrate assemblage standard that it could be, it has been clear that new excavations need to be undertaken. We reinitiated our research at Höwenegg in the Summer of 2003. Our objectives were to reopen an east-west trending 10 meter long geological trench at the site and begin our exploration for new fossil remains of plant, invertebrate and vertebrate material. During the first week of excavation we discovered the distal limb elements of a Miotragocerus skeleton in the trench. In the second week we uncovered this specimen and found that it was a complete skeleton (female with two full term fetuses in situs utero). In very close association to this individual, we discovered a second Miotragocerus skeleton along with a complete skeleton of the turtle, Trionyx. In addition to these individuals we found abundant in situ remains of molluscs, leaves, fruits and a new species of fossil cervid. In 2004, we continued working in this trench and removed yet another skeleton of Miotragocerus, and more invertebrate and fossil plant material. In addition, we opened a six meter geological trench approximately 50 meters to the north and established for the first time that fossiliferous Höwenegg deposits occur outside the classical collecting area. In this new trench we uncovered a rich fossil layer with remains of a land turtle (not Trionyx), a rhinoceros, fishes and stratigraphic horizons rich with gastropods and leaves. In 2004 also a 22 meter deep core was drilled on the north edge of the new excavation and in close juxtaposition to the local basaltic intrusion. This core transected the complete Höwenegg section locally as well as the contact between the Höwenegg beds and the underlying Teriary sediments. A detailed stratigraphic and sedimentologic study of the core is being undertaken by Ruth Haas, University of Karlsruhe. Our two year pilot project conclusively demonstrated that Höwenegg remains an immensely rich locality readily amenable to the recovery of further fossil remains and broad paleoenvironmental analyses (Heizmann et al., 2003). In the Summer of 2005 we undertook extensive excavations with scientific staff from the Natural History Museums of Karlsruhe and Stuttgart with the aim of gaining a better understanding of the spectacular accumulation of fossil vertebrates, invertebrates and diverse plant material at Höwenegg. The continued retrieval of articulated vertebrate skeletons, some with fetuses in situs utero, and an unprecedented retrieval of a diverse paleobotanical record means that at the Höwenegg we have the potential of securing a paleobiological reconstruction for the locality that is rare in the geological record (Heizmann et al., 2003). The 2006-2008 field seasons uncovered a major westward extension of the Höwenegg bone beds and further revealed that Unit 11 (Tobien and Jörg’s Unit 20) has yielded 13 skeletons (Munk et al., 2007, Bernor et al., 2008 and Bernor et al., in prep.). New skeletons include Miotragocerus, Hippotherium and Aceratherium. Unit 11 also has yielded the most diverse biotic elements including diverse plants (pollen, fruits, leaves), invertebrates and vertebrates. Our work going forward will be to understand the kill mechanism underlying the abundant fossil accumulation and preservation of the fossil vertebrates as well as the paleoenvironmental context and paleoecology of the fauna and flora using a broad range of analytical techinques. Acknowledgements – We thank Dr. Chris Liu for inviting us to present our results on the Höwenegg Lagerstaetten. We are grateful to the National Science Foundation and LSB Leakey Foundation for supporting our research at the site. We would like to thank our many colleagues at the Natural History Museums of Karlsruhe and Stuttgart for their work at the site. References Cited Beaumont, G. de. 1986. Les carnivores (Mammifères) du Néogène de Höwenegg (Hegau, Baden-Würtemberg). Carolinea 44: 35-43. Bernor, R.L., H. Tobien, L.A.- Hayek and H.-W. Mittmann. 1997. The Höwenegg Hipparionine Horses: Systematics, Stratigraphy, Taphonomy and Paleoenvironmental Context. Andrias 10: 1-230. Bernor, R.L., J. Eder, A.J. Kaufman, H.-W. Mittmann and D. Wolf. 2008. Multidisciplinary Paleobiological Research at the Late Miocene (MN9) Locality of Höwenegg, Germany. Society of Vertebrate Paleontology Abstracts for Annual Meeting, Cleveland, Ohio, October, 2008. Heizmann, E.P.J., W. Munk, A. Ziems, R.L. Bernor and H. König. 2003. Neue Grabungen am Höwenegg (Gemeinde Immendingen, Landkreis Tuttlingen, Baden-Württemberg). Bericht über die Pilotgrabung vom 16. 6. 2003 bis zum 11. 7. 2003. Carolinea 61: 5–16. Hünermann, K.A. 1982. Die Nashornskelette (Aceratherium incisivum Kaup 1832) aus dem Jungtertiär vom Höwenegg im Hegau (Südwestdeutschland, Vallesium, Obermiozän). Andrias 8: 13-64. Jörg, E. 1965. Ophiosaurus acuminatus nov. spec. (Anguidae, Rept.) von der pontischen Wirbeltierfundstätte Höwenegg (Hegau). Beitr. naturk. Forsch. SüdwDtl. 24: 21 - 30. Jörg, E., H. Rest and H. Tobien. 1955. Die Ausgrabungen der Jahre 1950-1954 an der jungtertiären Fossilfundstelle Höwenegg/Hegau. Beitr. naturkundl. Forsch. Südwestdeutschland. 14: 13. Jörg, E. and K. Rothausen. 1991. Zur Schichtfolge und Biostratonomie der Wirbeltierfundstelle Höwenegg (Hegau, Südwestdeutschland, Vallesium, Obermiozän). Andrias 8: 13-64. Munk, W., R.L. Bernor, E. Heizmann and H.-W. Mittmann. 2007 Excavations at the Late Miocene MN9 (10.3 Ma) Locality of Höwenegg (Hegau), Germany, 2004-2006. Carolinea 65:5-13. Nelson, S.V. 2003. The extinction of Sivapithecus: the faunal and environmental changes surrounding the disappearance of a Miocene hominoid in the Siwaliks of Pakistan. American School of Prehistoric Research, Monograph Series. Vol. 1: 1-136. Schleich, H.H. 1985. Zur Verbreitung tertiärer und quartärer Reptilien und Amphibien. I. Süddeutschland. Münchner Geowissenschaftliche Abhandlungen. (a) 4: 67-149. Schleich, H.H. 1986. Vorläufige Mitteilung zur Bearbeitung der fossilen Schildkröten der Fundstelle Höwenegg. Carolinea 44: 47-56. Swisher, C.C. III. 1996. New 40Ar/39Ar dates and their contribution toward a revised chronology for the late Miocene nonmarine of Europe and west Asia. pp. 64-77. In R.L. Bernor, V. Fahlbusch and H.-W. Mittmann (eds.). The Evolution of Western Eurasian Later Neogene Faunas. Columbia University Press, New York. Tobien, H. 1957. Die Bedeutung der unterpliozänen Fossilfundstelle Höwenegg für die Geologie des Hegaus. Jh. Geol. Landesamt, Bad.-Württ. 2: 193-208. Tobien, H. 1986. Die jungtertiäre Fossilgrabungsstätte Höwenegg im Hegau (Südwestdeutschland). Ein Statusbericht. Carolinea 44: 9-34. Tobien, H. and E. Jörg. 1959. Die Ausgrabungen an der jungtertiären Fossilfundstätte Höwenegg (Hegau). 1955-1959. Beitr. Naturkdl. Forsch. SüdwDtl. 18:175-191. Woodburne, M.O., R.L. Bernor and C.C. Swisher III. 1996. An Appraisal of the Stratigraphic and Phylogenetic Bases for the "Hipparion Datum" in the Old World. pp. 124-136. In R.L. Bernor, V. Fahlbusch and H.-W. Mittmann (eds.). The Evolution of Western Eurasian Later Neogene Faunas. Columbia University Press, New York. Zapfe, H. 1989. Chalicotherium goldfussi Kaup aus dem Vallesium vom Höwenegg im Hegau (Südwest-deutschland). Andrias 6: 117-128. Alnus Paleobiogeography in North America: New Fossils, New Insights Nathan A. Jud and Scott L. Wing (Smithsonian Institution, Washington DC 20013) The genus Alnus (Betulaceae) is comprised of about 35 species of early successional, actinorhizal trees distributed widely across the Northern Hemisphere and into South America along the Andes. The genus is known for its rich fossil record, attributed to the plants' affinity for environments that typically accumulate sediment, and the distinctive woody reproductive structures that preserve well with the leaves. Close examination of leaf architecture, reproductive structures, and wood anatomy in living and fossil Alnus indicates that some features can be used to determine subgeneric affinities in the fossils and thereby improve taxonomic resolution. An exhaustive survey of living and fossil alders in North America has been carried out in order to gather important geographic, temporal, climatic, and new taxonomic data with which to reconstruct the paleobiogeography of Alnus in the Americas. The earliest unequivocal Alnus foliage and reproductive structures in North America come from the Bighorn Basin, Wyoming. These previously unpublished fossils date to the Earliest Eocene (~55.3mya) and belong to the most derived subgenus: Gymnothyrsus sensu Murai 1964; Navarro et al 2003 or Alnus sensu Furlow 1979; Chen and Li 2004. The distinctive Alnus parvifolia, described by Wolfe and Wehr in 1987 from the Republic flora, and fossil wood from the Middle Eocene of Yellowstone, described by Wheeler et al in 1977, also belong to the most derived subgenus. The abrupt appearance of the most derived subgenus in North America during the Earliest Eocene, along with reports of putatively Paleocene Alnus megafossils in Asia suggests that the genus originated somewhere in Asia, and that the various clades within Alnus have migrated to North America via high latitude land bridges during the globally warm Paleogene. Aspects of an arborescent lycopsid from the Early Carboniferous of Virginia Patricia G. Gensel (University of North Carolina, Chapel Hill, NC) and Kathleen Pigg (Arizona State University) Grape seeds (Vitis) from the late Neogene Gray Fossil Site, northeast Tennessee Fade Gong, Istvan Karsai, and Yusheng (Chris) Liu (East Tennessee State University, Johnson City, TN) The unique seed morphology of Vitaceae (grape family) has been commonly used in the recognition and identification of the fossil seed remains of this family. This study focuses on the morphometric and systematic studies of fossil vitaceous seeds, recently recovered from the Gray Fossil Site (7-4.5 ma, latest Miocene–earliest Pliocene), northeastern Tennessee. Morphologically, the following characters, such as the smooth dorsal surface with a centrally positioned chalaza connected with a conspicuous chalaza-apex groove and short linear ventral infolds which are slightly diverged apically, correspond to extant subgenus Vitis (genus Vitis). A multivariate analysis based on eleven measured characters from 76 intact seeds proposes three types of seeds, each of which would be considered to represent a morphotaxon. Further comparison with modern and fossil vitaceous specimens defined these morphotaxa to three new taxa: Vitis sp.1, Vitis sp2, and Vitis sp.3. Diagnostic characters for Vitis sp.1 are the narrow obovoid surface view with a trapezoidal beak continuing the outline of the seed and a narrow elongate to elliptical chalaza on dorsal surface. Vitis sp2 is characterized by the subglobose shape with a stilliform to round chalaza, while Vitis sp.3 has big size seed body with a prominent beak, a pyriform to spatulate chalaza and a wide deep chalaza-apex groove passing over the seed apex and from a “V-shape” groove at the top of the raphe ridge. The discovery of diverse Vitis seeds from the Gray Fossil Site suggests that the Neogene woody ecosystem of this region proposed by previous study. In addition, the close resemblance between the first two fossil grapes (Vitis sp.1 and V. sp.2) with East Asian Vitis provides further evidence of the East Asian aspects of the flora from southeastern North America as late as the late Neogene. Paleoclimate reconstruction of the late Neogene flora from Gray, Tennessee Yusheng (Chris) Liu and Michael Zavada (East Tennessee State University) The Gray fossil site, dated as 7-4.5 million-year-old by associated vertebrate fossils, has yielded many excellently preserved plant fossils, among which fossil fruits/seeds are well present. Other than those, charcoals are not uncommon. So far, we have recognized at least 35 genera, representing more than 25 families of seed plants. The dominant genera include Carya and Quercus. Based on the nearest living counterpart comparisons, these fossils are identified with certainty to modern genera. Coexistence Approach is used to reconstruct the paleoclimate these fossil plants imply. Seven climatic parameters are calculated as follows:
The comparison indicates that the Gray region was under a climate different from the modern one, especially its winter in the late Neogene was much warmer, which explains the occurrence of alligators in the fossil record. Furthermore, the much drier month at Gray in the past might trigger intensive forest fires, which contribute the common presence of charcoals. The fossil record of Brassicaceae Steven R. Manchester (Florida Museum of Natural History, University of Florida, Gainesville, FL 32611) Palynology of the Caballos Formation (Lower Cretaceous; Colombia) and tropical paleoclimatic implications derived from its floristic composition Paula J. Mejia, David L. Dilcher (Florida Museum of Natural History, University of Florida, Gainesville, FL 32611) and Carlos A. Jaramillo (Smithsonian Tropical Research Institute Unit 0948, Panama City, Panama APO AA 34002) Flowering plants are the most important floristic component of modern ecosystems. However, there are still many questions regarding their origin, diversification and fast radiation during the Cretaceous. The only way to resolve these questions is to study their fossil record. The main objective of this study was to reconstruct the floral composition of a tropical site (Upper Magdalena Valley, Colombia) of Lower Cretaceous age using quantitative analyses of 39 palynological samples to determine the type of ecosystems present at that time interval in this tropical site. The floristic composition results show that the tropical ecosystems of Lower Cretaceous age represented in the Caballos Formation were composed mainly of ferns and gymnosperms, with gnetales and flowering plants as minor components (averages: 122, 65, 5 and 2 individuals and 21, 7, 4 and 1 species per sample respectively). The dominance of ferns is indicative of humid environments. These results differ from the expected floristic composition of tropical ecosystems from the Lower Cretaceous. Based on the palynological floristic provinces proposed by Herngreen et al. (1996), tropical latitudes were characterized by dominance of gymnosperms, common gnetalean pollen grains and absence of spores during the Lower Cretaceous, which has been interpreted as indicative of dry or arid climates. However, results from this and other palynological studies have shown floristic compositions typical of humid areas rather than the expected arid floras (de Lima 1990, Herngreen and Dueñas 1990, Schrank 1992), which indicates that maybe the widespread aridity hypothesis is not accurate and needs to be reevaluated. Ongoing analyses to test if the tropics were arid or humid during the Lower and mid-Cretaceous comprise the quantitative analysis of other five tropical sites of similar age plus the use of four other quantitative studies. In addition of the use of floristic composition as a climatic proxy I plan to use another independent proxy: clay content analysis. Pleistocene Climate Inferences FromTwo Southeast Asian Paleofloras ¹B. Roger Moore, Northeastern Research Institute of Petrified Wood and Mineral Resources, Nakhon Ratchasima Rajabhat University, 30000 Thailand; ²Paul J. Grote, School of Biology, Institute of Science, Suranaree University of Technology, 111 University Ave., Nakhon Ratchasima, 30000 Thailand; ¹Jaroon Duangkrayom, Northeastern Research Institute of Petrified Wood and Mineral Resources, Nakhon Ratchasima Rajabhat University, 30000 Thailand; ¹Yupa Thasod, Northeastern Research Institute of Petrified Wood and Mineral Resources, Nakhon Ratchasima Rajabhat University, 30000 Thailand The Pleistocene climate in the tropics of the Northern Hemisphere is relatively unknown. Two middle Pleistocene paleofloras recently investigated from Nakhon Ratchasima province, Northeast Thailand, reveal diverse assemblages of well preserved angiosperm leaves and reproductive organs which are instructive for interpreting the paleoclimate. Six dicotyledonous families; Dipterocarpaceae (Dipterocarpus), Sterculiaceae (Pterospermum), Anacardiaceae (Mangifera), Lythraceae (Lagerstroemia), Leguminosae, Bombacaceae, and one monocotyledonous family, Poaceae - bamboo, have been identified from alluvial deposits at Tha Chang. As impressions, leaves and reproductive organs from a laminated travertine deposit near Pak Chong have been identified as belonging to the families; Tiliaceae (Microcos), Euphorbiaceae (Bridelia), Moraceae (Ficus), Dipterocarpaceae (Shorea), Leguminosae “Caesalpinioideae” (Bauhinia), Guttiferae (Garcinia) and Poaceae (bamboo). Gross morphology of other leaf morphotypes appears to be similar to that of extant leaves of Lauraceae, Annonaceae, Magnoliaceae, and Anacardiaceae. Considering that the diversity and taxonomic relatedness of these two paleofloras is similar to modern day floras in Thailand, the Pleistocene climate of Northeast Thailand is judged to be very similar to that at present which is a tropical seasonal climate. Updates from NSF program Judy Skog (National Science Foundation) Late Pleistocene (Sangamonian stage) fossil plants within Mobile River terrace near Mount Vernon, Alabama Debra Stults and Brian Axsmith (Department of Biology, University of South Alabama, Mobile, AL 36688) A newly-discovered Pleistocene fossil plant locality within the Mobile-Tensaw Delta in southwest Alabama is producing abundant macrofossil remains of Liquidambar, Nyssa, Carya, Quercus, Betula, Carpinus, Vitis, Pinus, and other taxa. This is significant, as Pleistocene plants are rare in the southeastern United States. Many of the most well-preserved specimens are fruits, although leaves and rhizomes have also been recovered. Identifications are preliminary, but most appear to represent extant genera and species. The Mobile River is in the northern portion of the Mobile-Tensaw Delta valley. Commonly, this area is categorized as a delta, although it is more correctly considered a ‘drowned alluvial plain and valley’ (Smith, 1988). The difficulty in dating sediments within the region is probably a reflection of its geomorphological complexity, for there is evidence of many river and marine terraces that have accumulated as base level has changed with each glacial/interglacial sequence. Optical luminescence dating of sediment samples indicates an approximate age of the site of 85,000 kyr BP. More Woods of Yellowstone National Park Elisabeth Wheeler (NC State University and NC Museum of Natural Sciences) |
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Report any error and comments to Dr. Chris Liu at liuc@etsu.edu Updated March 2, 2009