Paleontology Commons^™

Microstratigraphic Analysis Of Burrow-Reworked Dinosaur Track Bed At Joanna's Track Site, Cretaceous Glen Rose Formation, Glen Rose, Texas, Michael Blair, Benjamin Dattilo, Anthony Martin, James Farlow

Benjamin F. Dattilo

Although dinosaur trackways are common in the Cretaceous Glen Rose Formation of Texas, the recently discovered Joanna track site illustrates a unique ichnological relationship where dinosaur tracks were disrupted by invertebrate burrows made long after burial. In an effort to document the precise sequence of events, we described the interval from 0.3 m below the track layer through 2.7 m above it in a vertical outcrop adjacent to the track site, focusing on the 70-cm of strata immediately above the track horizon. An 8-meter N-S cross-section of this 70-cm interval was power-washed, examined for trace fossils, body fossils, and lithology …

Stirred Not Shaken: Using Taphonomy To Reconstruct Paleoecological Succession And Taphonomic Feedback In A Cincinnatian (Ordovician, Ohio) Storm-Disturbed Shell Bed, Rebecca Freeman, Benjamin Dattilo, Aaron Morse, Michael Blair, Steve Felton, John Pojeta

Benjamin F. Dattilo

Walker and Alberstadt’s 1975 idea that a single shell bed contains a record of ecological succession has seemingly been refuted through stratinomic studies. These studies suggest that fossils are destroyed and accumulations are reworked by storms to the point of obliterating any record of successional-scale changes in faunas. Therefore storm-disturbed shell beds are not considered ideal for reconstruction of paleoecological succession.

Nevertheless, a storm-winnowed shell bed from the Fairview Formation, Ohio preserves a wide variety of shells in a range of taphonomic conditions that reveal succession-like changes. Exceptionally-preserved lingulid brachiopods found as intact pyrite-lined spar-filled shells rule out the final …

Dinosaur Tracksites Of The Paluxy River Valley (Glen Rose Formation, Lower Cretaceous), Dinosaur Valley State Park, Somervell County, Texas., James O. Farlow, Mike O'Brien, Glenn J. Kuban, Benjamin F. Dattilo, K. T. Bates, Peter L. Falkingham, L. Pinuela, Amanda Rose, A. Freels, C. Kumagai, Courtney Libben, Justin Smith, J. Whitcraft

Benjamin F. Dattilo

In 1940 R.T. Bird of the American Museum of Natural History collected segments of a sauropod and a theropod trackway from a site in the bed (Glen Rose Formation; Lower Cretaceous) of the Paluxy River, in what is now Dinosaur Valley State Park (Glen Rose, Texas, USA). However, Bird left undocumented thousands of other dinosaur footprints from this and other Paluxy tracksites. In 2008 and 2009 our international team carried out fieldwork to create detailed photomosaics of extant Paluxy tracksites, using GIS technology to combine these with historic maps and photographs. We also made photographs, tracings, LiDAR images, and measurements …

The Curse Of Rafinesquina: Negative Taphonomic Feedback Exerted By Strophomenid Shells On Storm-Buried Lingulids In The Cincinnatian (Katian, Ordovician) Series Of Ohio, Rebecca Freeman, Benjamin Dattilo, Aaron Morse, Michael Blair, Steve Felton, John Pojeta

Benjamin F. Dattilo

Thousands of lingulid brachiopods were found clustered beneath hundreds of individual valves of the strophomenid brachiopod Rafinesquina in the Upper Ordovician of Ohio. This association suggested a relationship between the two brachiopods, but the nature of this relationship was unclear. We utilized serial thin sectioning to examine these brachiopods and to determine the origin of the bed in which they were found. Sedimentary structures, mixed taphonomies, and stratigraphic and paleogeographic setting suggest that the lingulids occupied a hiatal concentration that had previously been reworked, but not significantly transported, by tropical storms. The final burial event was a storm that exhumed …

Remarkable Preservation Of A New Genus And Species Of Limuline Horseshoe Crab From The Cretaceous Of Texas, U.S.A., Rodney Feldman, Carrie Schweitzer, Benjamin Dattilo, James Farlow

Benjamin F. Dattilo

A single specimen, part and counterpart of a carapace, of a horseshoe crab from the Lower Cretaceous (Albian) Glen Rose Formation in north-central Texas, forms the basis for the definition of a new genus and species, Crenatolimulus paluxyensis. The discovery represents only the fifth limuline known from the Cretaceous. Its preservational style is remarkable in that the carapace exterior is faithfully replicated by a massive overgrowth of serpulid worms.

Conodont Biostratigraphy Across A Conformable Sauk–Tippecanoe Megasequence Boundary, Western Central Utah., Raymond Ethington, James Miller, Benjamin Dattilo, Rebecca Freeman

Benjamin F. Dattilo

The Sauk–Tippecanoe Megasequence boundary is a major unconformity in cratonic Laurentia and in the Appalachians. In contrast, the western margin of Laurentia in west-central Utah preserves a thick, continuously deposited record of the Whiterockian Regression at the top of the Sauk Megasequence (Middle Ordovician). Relevant strata include the Lehman Formation (limestone, shale), Watson Ranch Quartzite (sandstone, limestone, shale), and Crystal Peak Dolomite (dolomite, limestone).

Prominent facies changes occur in the Watson Ranch Quartzite, which is all sandstone near Ibex (southern Barn Hills), is sandstone with sandy carbonate and carbonate interbeds 12 miles SW near Crystal Peak (southern Confusion Range), and …

Middle Paleozoic Sequence Stratigraphy And Paleontology Of The Cincinnati Arch: Part 2 Northern Kentucky And Se Indiana, Carlton Brett, Benjamin Dattilo, Patrick Mclaughlin, Thomas Schramm, James Thomka, Bradley Cramer

Benjamin F. Dattilo

No abstract provided.

How Many Track Horizons Are Exposed At Dinosaur Valley State Park? Stratigraphy Of The Cretaceous Glen Rose Formation Track Sites Of The Paluxy River, Glen Rose, Texas, Benjamin Dattilo, Sadye Howald, James Farlow, Anthony Martin

Benjamin F. Dattilo

The dinosaur tracks of the Glen Rose Formation in the Paluxy River at Dinosaur Valley State Park are among the best preserved and most abundant in the world. While many track sites are easily correlated to the Main Tracksite, others, especially those at the extreme ends of the park, are differently preserved and not obviously correlated. To count track horizons, several stratigraphic sections were measured along the river from upstream at the McFall Ledge Site to 7.6 km downstream at the County Road 1001 crossing (3.1 km linear distance). These reveal 6 meters of strata separating two track-bearing horizons exposed …

The Mollusk-Rich Ordovician Miamitown Shale Mapped From Cincinnati To The Bluegrass: Probing Contemporaneous Peritidal Deposits To Decipher The Paleobathymetric Problem Of A Puzzling Pelite., Benjamin Dattilo, Thomas Schramm, Sasha Mosser, Lydia Mark, William Ward

Benjamin F. Dattilo

While most Upper Ordovician (Katian stage) strata in the Cincinnati region can be characterized as mixed carbonates and mudstones, there are a few carbonate-poor silty mudstone units including the Maysvillian Miamitown Shale and the Richmondian Waynesville Formation. These are characterized by molluscan faunas that contrast with the typical brachiopod-bryozoan fauna of the Cincinnatian, or, for that matter, of the Lower Paleozoic in general. The paucity of more widespread common taxa makes it difficult to use such assemblages in determining paleoenvironmental conditions, particularly water depth. Thus, combined with the lack of distinctive sedimentological indicators, it is difficult to say if these …

Sedimentology And Microstratigraphy Of A Cincinnatian Edrioasteroid Obrution Deposit., Aaron Morse, Benjamin Dattilo, David Meyer, Lydia Mark, Michael Harrison

Benjamin F. Dattilo

The Manchester edrioasteroid pavement is a shell layer in mudrock from the Corryville Formation (U. Ordovician, Maysvillain). No previous studies have examined sediments that buried Cincinnatian edrioasteroid pavements. To address this problem, a 16 cm thick stratigraphic sample measuring 90 cm by 30 cm was collected with a plaster jacket, dried for 2 years, then encased in fiberglass for dry cutting into slabs 2-4 cm thick. These were hardened with epoxy and polished dry with sandpaper. A prepared slab was sent to Bruker AXS for analysis using the M4 Tornado µ-XRF.

Delicate colonies of bryozoans, embedded in mudrock were found …

The Orientation Of Strophomenid Brachiopods On Soft Substrates, Roy Plotnick, Benjamin Dattilo, Daniel Piquard, Jennifer Bauer, Joshua Corrie

Benjamin F. Dattilo

Strophomenid brachiopods have long been interpreted as ‘‘snowshoe’’ strategists, with their flattened concavoconvex valves providing resistance to foundering in very soft sediments. There has been a sharp difference of opinion in whether the shells were oriented with their convex or their concave surface in contact with the sediment. This study, along with independent evidence from sedimentology, ichnology, and morphology, indicates that the strophomenids lived with their shells concave down (convex up). Experiments indicate the force required to push shells into soft cohesive muds is much greater for the convex up than for the convex down orientation. Forces also increase with …

An Enigmatic Lobate Mat-Like Fossil(?) In The Kope Formation (Upper Ordovician), Kenton County, Kentucky, Ron Fine, Carlton Brett, Benjamin Dattilo, David Meyer

Benjamin F. Dattilo

A new, enigmatic, large fossil(?) object from a thin silty mudstone bed (up to 3 cm thick) underlain by siltstone was excavated from the lower Kope Formation (Economy Member, basal Pioneer Valley submember) near Covington, KY. The excavated object is roughly elliptical in outline, over 2 m long, with a parallel-fluted structure at one end that terminates in a complex of conjoined, flattened, ellipsoidal or spatulate concretion-like lobes at the other end. The lobes are about 10 cm and range to 45 cm long. Internally, some lobes show lamination, sometimes convoluted. The most perplexing feature of the lobe-like structures is …

Upper Ordovician Strata Of Southern Ohio-Indiana: Shales, Shell Beds, Storms, Sediment Starvation, And Cycles, Carlton Brett, Thomas Schramm, Benjamin Dattilo, Nathan Marshall

Benjamin F. Dattilo

The Cincinnatian Series (ca. 450 to 442 Ma) of the Cincinnati Arch features some of the most spectacular Ordovician fossils in the world. The rich faunas of bryozoans, brachiopods, molluscs, echinoderms, and trilobites are preserved as discrete shell-rich limestones, cyclically interbedded with sparsely fossiliferous shales and mudstones that may yield exceptionally preserved trilobites and crinoids. Similar successions of shell beds interbedded with mudstones are common components of Paleozoic successions. In such successions, the genesis of the highly concentrated shell beds is often attributed to storm-winnowing, but is this the whole story? This trip will offer an overview of the classic …

Integrating Bio-, Chemo-, Chrono-, Gamma-Ray, Litho-, And Sequence Stratigraphy In The Upper Cambrian And Lower Ordovician: Progress Toward A Comprehensive Stratigraphic Framework, James Miller, Benjamin Dattilo, Raymond Ethington, Kevin Evans, Rebecca Freeman, James Loch, John Repetski, Robert Ripperdan, Anthony Runkel, John Taylor

Benjamin F. Dattilo

Chronostratigraphic classification of the Laurentian Upper Cambrian and Lower Ordovician is based on strata in Utah, Nevada, Missouri, Minnesota, Wisconsin, and Alberta. Biozonations are based on strata there as well as in Texas and Oklahoma. Regional trilobite zonations vary somewhat because of facies influence and periods of regional endemism; the zonation is quite different in slope deposits. Conodont zonation begins in the middle Upper Cambrian; many taxa occur in a variety of facies and are cosmopolitan, so zones can be correlated across Laurentia and globally. Calcitic brachiopod zones established in Oklahoma have been identified in other areas where faunas have …

Fine-Scale Lithologic Variations In Late Ordovician (Katian) Pertidal Depositions Of The Kentucky Bluegrass Suggest Sea-Level Fluctuations As The Primary Mechanism For Type Cincinnatian Meter-Scale Cycles., Sasha Mosser, Thomas Schramm, Benjamin Dattilo, Carlton Brett, Rebecca Freeman, Michael Blair

Benjamin F. Dattilo

Late Ordovician peritidal facies of central Kentucky are laterally equivalent to cyclic subtidal facies of the Cincinnati region but correlation details, and causes of cyclicity are poorly understood. If type Cincinnatian shale-limestone (meter scale) cycles were driven by sea-level fluctuations then equivalent peritidal facies should be cyclic. Likewise, the same magnitude of base level change should result in greater environmental variability in these shallow facies. If cycles are of Milankovitch origin, it should be reflected in cycle duration. We attempt to test these predictions by examining litho, sequence, and macro-biostratigraphic evidence at Point Leavell, KY and other localities. Exposures at …

The Brachiopod Trap: What Their Oldest (Upper Ordovician, Ohio) Failed Escape Burrows Tell Us About The Evolution Of Burrowing In Lingulids, Rebecca Freeman, Benjamin Dattilo, Aaron Morse, Michael Blair, Bryan Utesch, Steve Felton, John Pojeta

Benjamin F. Dattilo

Infaunal organisms living in shallow marine settings are vulnerable to exhumation during storms or entombment by storm-deposited sediments. Cambrian­–Early Ordovician lingulids included epifaunal as well as possible infaunal forms. However, many epifaunal forms became extinct during the Middle Ordovician, and Late Ordovician lingulids were similar in their infaunal habits and marginal habitats. Modern infaunal lingulids are able to reorient themselves after burial in sediments, but it is unclear when this ability evolved. Initial burrowing of juvenile lingulids, as well as re-burrowing of exhumed modern lingulids involves digging downwards and then back up in a u-shape, but successful escape burrowing involves …

The “Curse Of Rafinesquina:” Negative Taphonomic Feedback Exerted By Strophomenid Shells On Storm-Buried Lingulids In The Cincinnatian Series (Katian, Ordovician) Of Ohio, Rebecca Freeman, Benjamin Dattilo, Aaron Morse, Michael Blair, Steve Felton, John Pojeta

Benjamin F. Dattilo

Taphonomic feedback is the idea that accumulation of organic remains either enhances the habitat for some organisms (positive taphonomic feedback), and/or degrades the habitat for others (negative taphonomic feedback). Examples of epibionts living on skeletal remains are direct evidence of positive taphonomic feedback. Disruption of infaunal burrowing activities by skeletal fragments is an example of negative taphonomic feedback; direct fossil evidence of this phenomenon has not been documented previously. Infaunal organisms are vulnerable to exhumation or entombment during storms, but organisms that burrow can also re-establish viable life positions subsequently. For example, when modern lingulids re-burrow after exhumation, they first …