Richard H. Fluegeman

The Pipe Creek Sinkhole Biota, a Diverse Late Tertiary Continental Fossil Assemblage from Grant County, Indiana

Abstract Quarrying in east-central Indiana has uncovered richly fossiliferous unconsolidated sediment buried beneath Pleistocene glacial till. The fossiliferous layer is part of a sedimentary deposit that accumulated in a sinkhole developed in the limestone flank beds of a Paleozoic reef. Plant and animal (mostly vertebrate) remains are abundant in the fossil assemblage. Plants are represented by a diversity of terrestrial and wetland forms, all of extant species. The vertebrate assemblage (here designated the Pipe Creek Sinkhole local fauna) is dominated by frogs and pond turtles, but fishes, birds, snakes and small and large mammals are also present; both extinct and extant taxa are represented. The mammalian assemblage indicates an early Pliocene age (latest Hemphillian or earliest Blancan North American Land Mammal Age). This is the first Tertiary continental biota discovered in the interior of the eastern half of North America.

Occurrence of Sievertsia (Echinodermata; Cyclocystoidea) from the Middle Devonian of northern Indiana

ROHR, D. M. 1977. Geographic distribution of the Ordovician gastropod Maclurites, p. 45-52. In J. Gray and A. J. Boucot (eds.), Historical Biogeography, Plate Tectonics and the Changing Environment. Proceedings of the 37th Annual Biology Colloquium and Selected Papers, Oregon State University Press, Corvallis. . 1980. Ordovician-Devonian Gastropoda from the Klamath Mountains, California. Palaeontographica Abteilung A, 171:141-199. , AND R. B. BLODGETT. 1985. Upper Ordovician Gastropoda from west-central Alaska. Journal of Paleontology, 59:667-673. --, AND -. 1988. First occurrence ofHelicotoma Salter (Gastropoda) from the Ordovician of Alaska. Journal of Paleontology, 62:304306. , AND A. J. BOUCOT. 1985. Some observations on the operculum of Oriostoma (Silurian Gastropoda). Canadian Journal of Earth Sciences, 22:294-296. , AND A. W. POTTER. 1987. Rousseauspira, a new Ordovician gastropod operculum. Journal of Paleontology, 61:284-289. SAINSBURY, C. L., J. T. DUTRO, JR., AND M. CHURKIN, JR. 1971. The Ordovician-Silurian boundary in the York Mountains, western Seward Peninsula, Alaska. U.S. Geological Survey Professional Paper, 750-C:C52-C57. SALTER, J. W. 1859. Figures and descriptions of Canadian organic remains, Decade 1. Geological Survey of Canada, Montreal, 47 p. STEELE, H. M., AND G. W. SINCLAIR. 1971. A Middle Ordovician fauna from Braeside, Ottawa Valley, Ontario. Geological Survey of Canada Bulletin, 211:1-96. SWAINSON, W. 1840. A Treatise on Malacology; or, Shells and Shellfish. Longmap, Orme, Brown, Green, and Longmans, London, 419 p. TOFEL, J. E., AND P. W. BRETSKY. 1987. Middle Ordovician Lophospira (Archaeogastropoda) from the upper Mississippi Valley. Journal of Paleontology, 61:700-723. ULRICH, E. O., AND W. H. SCOFIELD. 1897. The Lower Silurian Gastropoda of Minnestoa, p. 813-1081. In The Geology of Minnesota, Vol. 3, Pt. 2, Paleontology. Harrison and Smith, Minneapolis. WAHLENBERG, G. 1821. Petrificata tellurus svecanae examinata. Acta Societatis Regiae Scientiarum, Uppsala, 185 p. WENZ, W. 1938. Handbuch der Paliiozoologie, Bd. 6, Gastropoda. Berlin, 1639 p. (in German). WHITEAVES, J. F. 1890. Descriptions of eight new species of fossils from the Cambro-Silurian rocks of Manitoba. Proceedings and Transactions of the Royal Society of Canada for 1889, 7:75-83. WHITFIELD, R. P. 1886. Notice of geological investigations along the eastern shore of Lake Champlain, conducted by Prof. H. M. Seely and Prest. Ezra Brainerd of Middlebury College, with descriptions of the new fossils discovered. American Museum of Natural History Bulletin, 1:293-345. WILSON, A. E. 1951. Gastropoda and Conularida of the Ottawa Formation of the Ottawa-St. Lawrence Lowland. Geological Survey of Canada Bulletin 17, 149 p. ZITTEL, K. A. 1895. Grundziige der Palaeontologie. Munich and Leipzig, 971 p. (in German).ROHR, D. M. 1977. Geographic distribution of the Ordovician gastropod Maclurites, p. 45-52. In J. Gray and A. J. Boucot (eds.), Historical Biogeography, Plate Tectonics and the Changing Environment. Proceedings of the 37th Annual Biology Colloquium and Selected Papers, Oregon State University Press, Corvallis. . 1980. Ordovician-Devonian Gastropoda from the Klamath Mountains, California. Palaeontographica Abteilung A, 171:141-199. , AND R. B. BLODGETT. 1985. Upper Ordovician Gastropoda from west-central Alaska. Journal of Paleontology, 59:667-673. --, AND -. 1988. First occurrence ofHelicotoma Salter (Gastropoda) from the Ordovician of Alaska. Journal of Paleontology, 62:304306. , AND A. J. BOUCOT. 1985. Some observations on the operculum of Oriostoma (Silurian Gastropoda). Canadian Journal of Earth Sciences, 22:294-296. , AND A. W. POTTER. 1987. Rousseauspira, a new Ordovician gastropod operculum. Journal of Paleontology, 61:284-289. SAINSBURY, C. L., J. T. DUTRO, JR., AND M. CHURKIN, JR. 1971. The Ordovician-Silurian boundary in the York Mountains, western Seward Peninsula, Alaska. U.S. Geological Survey Professional Paper, 750-C:C52-C57. SALTER, J. W. 1859. Figures and descriptions of Canadian organic remains, Decade 1. Geological Survey of Canada, Montreal, 47 p. STEELE, H. M., AND G. W. SINCLAIR. 1971. A Middle Ordovician fauna from Braeside, Ottawa Valley, Ontario. Geological Survey of Canada Bulletin, 211:1-96. SWAINSON, W. 1840. A Treatise on Malacology; or, Shells and Shellfish. Longmap, Orme, Brown, Green, and Longmans, London, 419 p. TOFEL, J. E., AND P. W. BRETSKY. 1987. Middle Ordovician Lophospira (Archaeogastropoda) from the upper Mississippi Valley. Journal of Paleontology, 61:700-723. ULRICH, E. O., AND W. H. SCOFIELD. 1897. The Lower Silurian Gastropoda of Minnestoa, p. 813-1081. In The Geology of Minnesota, Vol. 3, Pt. 2, Paleontology. Harrison and Smith, Minneapolis. WAHLENBERG, G. 1821. Petrificata tellurus svecanae examinata. Acta Societatis Regiae Scientiarum, Uppsala, 185 p. WENZ, W. 1938. Handbuch der Paliiozoologie, Bd. 6, Gastropoda. Berlin, 1639 p. (in German). WHITEAVES, J. F. 1890. Descriptions of eight new species of fossils from the Cambro-Silurian rocks of Manitoba. Proceedings and Transactions of the Royal Society of Canada for 1889, 7:75-83. WHITFIELD, R. P. 1886. Notice of geological investigations along the eastern shore of Lake Champlain, conducted by Prof. H. M. Seely and Prest. Ezra Brainerd of Middlebury College, with descriptions of the new fossils discovered. American Museum of Natural History Bulletin, 1:293-345. WILSON, A. E. 1951. Gastropoda and Conularida of the Ottawa Formation of the Ottawa-St. Lawrence Lowland. Geological Survey of Canada Bulletin 17, 149 p. ZITTEL, K. A. 1895. Grundziige der Palaeontologie. Munich and Leipzig, 971 p. (in German).

A note on the biostratigraphy of Paleocene-Eocene larger foraminifera from western Cuba

Larger foraminifera were collected from various Paleocene and Eocene localities in western Cuba. Included was a mea- sured section at San Francisco de Paula in Ciudad de la Habana Province in the Apolo and Capdevila Formations. This section spans the Paleocene/Eocene boundary and has been the focus of intensive biostratigraphic work. In this study, the stratigraphic occurrences of the larger foraminifera were correlated to biozonations based on planktonic foraminifera, calcareous nannofossils, radiolaria, and smaller benthic foraminifera already identified at San Francisco de Paula. Most of the above localities consist of synorogenic sedimentary rocks and the larger foraminifera collected from these sites have in fact been transported to deep water. In order to obtain some in situ larger foraminfera, additional upper Paleocene and lower Eocene samples were obtained from 10 wells in episutural basins from throughout Cuba. In all, eleven species of larger foraminifera were identified from the upper Paleocene and lower Eocene of Cuba. These are: Ranikothalia catenula (Cushman and Jarvis) (=Operculina catenula 1932), Discocyclina barkeri Vaughan and Cole, Discocyclina anconensis Barker, Discocyclina weaveri Vaughan, Eoconuloides lopeztrigoi (Palmer) (=Amphistegina lopeztrigoi 1934), Eoconu- loides wellsi Cole and Bermudez, Eofabiania cushmani (Vaughan) (=Discocyclina cushmani 1929), Athecocyclina stephensoni (Vaughan) (=Discocyclina stephensoni 1929), Pseudophargmina cedarkeysensis, Cole, Hexagonocyclina cristensis (Vaughan) (=Orbitoclypeus? cristensis 1924), and Cushmania americana (Cushman) (=Conulites americana 1919). The larger foraminifera from Paleocene age samples contain an assemblage recognized throughout the Caribbean and Gulf Coastal Plain as the Ranikothalia catenula fauna. Eocene samples contain an assemblage of larger foraminifera refered to here as the Eoconuloides wellsi fauna. Based onI data collected at the San Francisco de Paula section, the change from the Ranikothalia catenula fauna to the Eoconuloides wellsi fauna appears to post-date the benthic faunal turnover associated with the bathyal realm.

Paleocene benthonic foraminiferal biostratigraphy of the eastern Gulf Coastal Plain

The Paleocene strata of eastern and central Alabama and western Georgia are rich in well preserved benthonic foraminifera but relatively poor in well preserved planktonic foraminifera. The portions of the Paleocene section lacking planktonic foraminifera can be integrated into the global geochronologic time scale through the use of benthonic foraminiferal assemblages. A paleontological analysis of benthonic foraminifera on 154 samples selected from the Eastern Gulf Coastal Plain provided the basis of a chronostratigraphic framework. Four biozones were defined: the Eponides elevatus Zone (= Zone Plb), the Alabamina midwayana Zone (= Zone Plc through lower P4), the Discorbis washburni Zone (= middle Zone P4) and the Alabamina westraliensis Zone (= upper Zone P4 through P6a). The use of benthonic foraminifera in local correlation is an effective tool, particularly in the case of surface and subsurface sections which have undergone diagenetic changes and do not contain well preserved planktonic microfossils. We anticipate that this biostratigraphic zonation may be effectively applied to other units of the Mississippi Embayment and the Gulf Coastal Plain.

The Bartonian (Middle Eocene) GSSP: Historical Considerations and Challenges

The Bartonian Stage is one of the standard stages of the Eocene. It has a complex history of usage dating from the mid-nineteenth century. In defining its GSSP, the Bartonian Working Group plans to honour the historical concept of the Bartonian Stage as originally identified in the Hampshire Basin, and will select a definition that does not truncate the “unit stratotype” of the Bartonian Stage. The Working Group recognizes that the lithostratigraphic concept of the Barton Clay Formation differs from the chronostratigraphic concept of the Bartonian Stage. It is proposed that the Nummulites prestwichianus bed in the Hampshire Basin be used to define the base of the historical Bartonian Stage in that region. Previously proposed guide events for the Bartonian Stage that both honour this definition and which may serve to define a GSSP include either the base or the top of magnetochron C19n, the first occurrence of planktonic foraminiferan Turborotalia cerroazulensis, and the last occurrence of the planktonic foraminiferan Guembelitrioides nuttalli. Additionally, the lowest occurrence of the calcareous nannofossil Reticulofenestra reticulata is a widely recognized biolevel that correlates closely with the base of C19n. Ongoing biostratigraphic and magnetostratigraphic work on sections in Spain and Italy will likely produce a GSSP for the Bartonian Stage.

The upper Paleocene-lower Eocene San Francisco de Paula section: Biostratigraphic synthesis

The San Francisco de Paula section is one of the few that permit direct correlations between siliceous and calcareous microfossil zonal schemes near the Paleocene/Eocene boundary. We discuss these correlations, delineate unconformities in the section and discuss the location of the Paleocene/Eocene boundary.