Scott M. Ritter

Upper Missourian-lower Wolfcampian (upper Kasimovian-lower Asselian) conodont biostratigraphy of the Midcontinent, U.S.A.

The Upper Missourian to lower Wolfcampian sequence (middle Kansas City through lower Council Grove Groups) of the Midcontinent U.S.A. (Kansas, Oklahoma, Nebraska, and Missouri) is divided into seven biostratigraphic zones defined chiefly upon first occurrences of Streptognathodus species. In ascending order, these are the: 1) Streptognathodus gracilis Zone; 2) Streptognathodus firmus Zone; 3) Streptognathodus pawhuskaensis deflectus Zone; 4) Streptognathodus virgilicus Zone; 5) Streptognathodus brownvillensis Zone; 6) Streptognathodus wabaunsensis s.l. Zone; and 7) Streptognathodus aff. barskovi Zone. The diagnostic Permian genus Sweetognathus first appears in the lower part of the S. aff. S. barskovi Zone. These zones coincide generally with Upper Carboniferous–Lower Permian conodont zones of Russia. Streptognathodus virgilicus , a new species common in the upper Shawnee and Wabaunsee Groups, is described.

Streptognathodus (Conodonta) succession at the proposed Carboniferous-Permian boundary stratotype section, Aidaralash Creek, northern Kazakhstan

Streptognathodus Pa elements dominate conodont faunas from the proposed Carboniferous-Permian boundary stratotype at Aidaralash Creek, northern Kazakhstan. The phyletic development of this genus provides the means for subdividing the late Gzhelian to early Sakmarian prodeltaic section (Beds 9-37) into six zones. The preferred Global Stratotype Section and Point (GSSP) for the base of the Permian System is 27 m above the base of Bed 19 at the first occurrence of Streptognathodus isolatus Chernykh, Ritter, and Wardlaw, 1996. This arbitrarily chosen point in the evolutionary continuum of nodose streptognathodids is recognizable in basinal rocks elsewhere in the Ural trough (lower part of Bed 16 at Usolka) as well as the cyclic shelf succession of the American Midcontinent (Glenrock Limestone Member of the Red Eagle Limestone). Eight new species of Streptognathodus occur in the Aidaralash collections: S. bellus n. sp., S. costaeflabellus n. sp., S. flexuosus n. sp., S. glenisteri n. sp., S. longilatus n. sp., S. rectangularis n. sp., S. sigmoidalis n. sp., and S. tenuialveus n. sp. In addition, three morphotypes with limited occurrence ( S. sp. A-C) are left in open nomenclature. New collections of topotype material from the nearby Tabantal River section permit clarification of S. barskovi (Kozur).

Streptognathodus isolatus new species (Conodonta): Proposed index for the Carboniferous-Permian boundary

Davydov et al. (1995) recently proposed the Aidaralash Creek section in northern Kazakhstan (Figures 2 and 3) as the Global Stratotype Section and Point (GSSP) for the base of the Permian System. The proposed boundary is the level in an evolutionary sequence where Streptognathodus wabaunsensis Gunnell gives rise to a descendent with an isolated node field on the inside of the upper platform surface. This morphotype constitutes a new and distinct species for which we propose the name Streptognathodus isolatus new species.

CONODONT SEQUENCE BIOSTRATIGRAPHY OF THE HERMOSA GROUP (PENNSYLVANIAN) AT HONAKER TRAIL, PARADOX BASIN, UTAH

Abstract In cyclical Pennsylvanian strata, conodonts find their greatest stratigraphic utility as biotic signatures of physically defined stratigraphic entities (cycles, parasequences, high frequency sequences, etc.) rather then the primary means of stratigraphic subdivision (e.g., biostratigraphic interval zones). The practice of identifying depositional entities for purposes of regional correlation on the basis of their constituent conodont faunas is herein called conodont sequence biostratigraphy. In this paper, the concept is utilized to successfully correlate Pennsylvanian cycles of the Paradox basin with their Midcontinent counterparts. The Honaker Trail section is the most accessible and well-studied succession of carbonate shelf strata in the Paradox basin. Approximately 350 m of cyclically bedded limestone, sandstone, and shale comprising 53 fifth-order cycles are exposed along the cliffs of the deeply entrenched San Juan River. Maximum transgressive facies of 19 cycles yielded Idiognathodus-Neognathodus- and/or Streptognathodus-dominated conodont faunas. Those from the Chimney Rock, Gothic, LHT-5, UHT-3, UHT-5, UHT-8, unnamed limestone, and Shafer correspond to faunas from the Verdigris, Lower Fort Scott, Altamont (Lake Neosho), Lost Branch, Hertha (Mound City), Swope (Hushpuckney), Dennis (Stark), and South Bend cycles of the Midcontinent, respectively. By extrapolation, all minor cycles of the Marmaton, Pleasanton, and Bronson Groups (except for the Critzer) also appear to have counterparts at Honaker Trail. The position of the Desmoinesian–Missourian boundary in the Honaker Trail section can be approximated using conodonts in conjunction with fusulinids. The highest Desmoinesian conodont fauna, the Idiognathodus nodocarinatus fauna, occurs in cycle UHT-3 in the lower part of the Upper Honaker Trail sequence. The highest occurrence of Beedeina occurs in the same cycle. The lowest conodont fauna with the Missourian species I. eccentricus appears two cycles higher, in cycle UHT-5. Because in the Midcontinent region a small interval of strata separates the first appearance of I. eccentricus from the base of the Missourian, we place the base of the Missourian at the base of cycle UHT-4 (bed 105) at Honaker Trail. The appearance of Streptognathodus firmus and S. pawhuskaensis in the Shafer limestone indicates that the Missourian–Virgilian boundary lies slightly above or below this stratigraphic horizon.

Near‐infrared spectroscopy of lacustrine sediments in the Great Salt Lake Desert: An analog study for Martian paleolake basins

The identification and characterization of aqueous minerals within ancient lacustrine environments on Mars are a high priority for determining the past habitability of the red planet. Terrestrial analog studies are useful both for understanding the mineralogy of lacustrine sediments, how the mineralogy varies with location in a lacustrine environment, and for validating the use of certain techniques such as visible–near-infrared (VNIR) spectroscopy. In this study, sediments from the Pilot Valley paleolake basin of the Great Salt Lake desert were characterized using VNIR as an analog for Martian paleolake basins. The spectra and subsequent interpretations were then compared to mineralogical characterization by ground truth methods, including X-ray diffraction, automated scanning electron microscopy, and several geochemical analysis techniques. In general, there is good agreement between VNIR and ground truth methods on the major classes of minerals present in the lake sediments and VNIR spectra can also easily discriminate between clay-dominated and salt-dominated lacustrine terrains within the paleolake basin. However, detection of more detailed mineralogy is difficult with VNIR spectra alone as some minerals can dominate the spectra even at very low abundances. At this site, the VNIR spectra are dominated by absorption bands that are most consistent with gypsum and smectites, though the ground truth methods reveal more diverse mineral assemblages that include a variety of sulfates, primary and secondary phyllosilicates, carbonates, and chlorides. This study provides insight into the limitations regarding the use of VNIR in characterizing complex mineral assemblages inherent in lacustrine settings.

Oldest and lowest latitudinal occurrence of Palaeoaplysina; Middle Pennsylvanian Ely Limestone, Burbank Hills, Utah

A primitive variety of Palaeoaplysina laminaeformis Krotov is the primary biotic constituent of a two-meter-thick biostrome in the upper Ely Limestone of western Utah. Associated fusulinaceans and stromatoporoids indicate an early Desmoinesian (Middle Pennsylvanian) age, making it the oldest documented occurrence of non-ancestral Palaeoaplysina in the world. Plate-supported packstone with 40-60% interstitial peloidal mud and silt-size fossil debris constitutes the dominant biostrome rock fabric. During the Late Carboniferous, non-ancestral palaeoaplysinids were restricted to the Ely and Sublett basins of Utah and Idaho, respectively. By Early Permian time, however, they played a significant role in the construction of reefs and biostromes across the entire northern margin of Laurussia.

Early Permian conodont assemblages from the Wolfcamp Shale, Midland Basin, West Texas

Nine assemblages of conodont elements have been found on bedding surfaces of the “Wolfcamp Shale’ from the Midland Basin, Texas. Four of these assemblages have Pa elements assigned to Sweetognathus cf. S. inornatus . The assemblages are classified taphonomically as apparatus (remains or partial remains of a single individual) or coprolitic associations. The two apparatus assemblages indicate that Sweetognathus cf. S. inornatus possessed a seximembrate apparatus comprised of Pa, Pb, M, Sa, Sb, and Sc elements. Five of the seven coprolitic associations contain numerous elements (50–100) and/or multiple pairs of Pa elements representing the presumably ingested remains of two or more conodonts. The “Wolfcamp Shale’ assemblages are significant because 1) they confirm the polygnathacean affinity of the family Sweetognathidae, 2) they represent the youngest polygnathacean assemblages currently known, and 3) they permit comparison of multielement Sweetognathus with homologous elements of coeval genera such as Hindeodus, Adetognathus, Streptognathodus , and Neostreptognathodus .

Morphometric patterns in Middle Triassic Neogondolella mombergensis (Conodonta), Fossil Hill, Nevada

The Fossil Hill Member of the Prida Formation (Fossil Hill, Nevada) yields one of the most continuous records of Middle Triassic conodont evolution currently known. Because of different taxonomic viewpoints, this record has been alternately interpreted to represent either morphological stasis or gradual, biostratigraphically significant morphogenesis. Univariate and multivariate morphometric analysis of 18 successive Neogondolella Pa element populations suggests that the majority of specimens at Fossil Hill (including N. constricta emend. sensu Nicora and Kovacs, 1984) belong to a single, morphologically diverse species, Neogondolella mombergensis (Tatge). Time series of individual character means from 18 stratigraphic horizons in the Fossil Hill display nondirectional morphologic trends for which a random walk model cannot be rejected. Time series of transformed multivariate means constitute biologs that may prove useful in regional correlation.

Evolution Education in Utah: A State Office of Education-University Partnership Focuses on Why Evolution Matters

Several groups of people are essential for effectively teaching the theory of evolution in public schools. Teachers of course are at the leading edge of educating students. However, school district administrators, school boards, state education officers, and university professors all play critical roles in this endeavor. Whereas scientific discoveries and teacher training typically occur at the university level, it is school district leaders and teachers who actually disseminate this information in a way that creates an educated population of students. In this study, we introduce a partnership focused on strengthening evolution education in Utah’s public schools. Our program centers on the importance of evolution as an applied science and one that can be readily integrated throughout the biology curriculum. Our 2-day workshop—conducted in each Utah school district—brings together elected school board members, school district administrators, public school science teachers, and university professors to overcome barriers that can arise when teaching the theory of evolution as part of the 7–12 public school curriculum.

Results of an experimental radar survey on the Gornergletscher glacier system (Zwillingsgletscher), Valais, Switzerland

A 775-m 200-MHz GPR traverse was surveyed in July 2009 over a portion of the Zwillingsgletscher branch of the Gornergletscher System, Valais, Switzerland. The survey line was approximately parallel to the glacial flow direction and situated in an area of prominent wave ogive formation. The traverse shows a well-developed pattern of scattering that is strongly folded into apparent troughs and ridges with the ridges commencing at 10-20 m depth. This pattern mimics the expected ogive structure. The origin of the scattering has not yet been confirmed, but is possibly related to an onset of warmer ice or to variations in rock or sediment content.