Palynology of the Dockum group (Upper Triassic), Texas, U.S.A.

Dunay, R. E.; Fisher, Michael J.

doi:10.1016/0034-6667(79)90025-3

Cited by 44 publications

(10 citation statements)

References 8 publications

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“…Phases with stoichometries Ag,K, AgK,, and AgK, were found 14. The charge density at the Wigner-Seitz radius can be determned from n , = 0.82 (KIVm)'", where K and V, are the bulk modulus (In gigapascals) and molar volume (in cub~c centimeters), respectively, at a gven pressure (72) Because the Miedema charge densty parameters are adjusted empirically from experlmental values (12), we estimated the charge densities at high pressure by addng a shift n charge density under pressure determined from ths equatlon to the Miedema value at ambent pressure. 15 T h e sources and paths of ancient river systems are generally traced by distinctive grains ( I ) , paleocurrents, and facies correlations, b~~t these arguments provide no uniaue ties between source areas and sites of deposition.…”

mentioning

confidence: 99%

Detrital Zircon Link Between Headwaters and Terminus of the Upper Triassic Chinle-Dockum Paleoriver System

Riggs

Lehman

Gehrels

et al. 1996

Science

151

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New detrital-zircon geochronologic data reveal that a through-going paleoriver connected Texas with Nevada in Late Triassic time. Sandstone from the Upper Triassic Santa Rosa Sandstone (Dockum Group) from northwestern Texas contains a detrital zircon suite nearly identical to that found in western Nevada in the Upper Triassic Osobb Formation (Auld Lang Syne Group, correlative with the Chinle Formation). The Santa Rosa Sandstone was derived in large part from the eroded Cambrian core of the Amarillo-Wichita uplift, as evidenced by abundant zircons with ages of 515 to 525 million years. Other zircon grains in the sandstone are Permian, Devonian, Proterozoic, and Archean in age and, with the exception of the Archean grain, are also matched by the population in the Nevada strata.

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mentioning

confidence: 99%

Detrital Zircon Link Between Headwaters and Terminus of the Upper Triassic Chinle-Dockum Paleoriver System

Riggs

Lehman

Gehrels

et al. 1996

Science

151

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“…Genus Froelichsporites, Litwin, Smoot, Weems 1993 Froelichsporites traversei (Dunay and Fisher 1979) Litwin, Smoot, Weems, 19931979 Pyramidosporites traversei n. sp.…”

Section: Systematic Palynologymentioning

confidence: 99%

“…Froelichsporties traversei was first described as Pyramidosporites traversei by Dunay and Fisher (1979) from +++ Later Litwin et al (1993) erected the new genus Froelichsporites to replace the generic assignment to Pyramidosporites. The distribution of the taxon is restricted to Upper Triassic formations of North America (e.g, Dunay and Fisher 1979;Fisher and Dunay 1984;Litwin et al 1991Litwin et al , 1993Cornet 1993, Fowell and Olsen 1993, Fowell et al 1994 (Fig. 1, Table 1) and similar forms have beenare described from Upper Triassic continental strata of Portugal 4 (Adloff et al 1974).…”

Section: Introductionmentioning

confidence: 99%

“…1, Table 1) and similar forms have beenare described from Upper Triassic continental strata of Portugal 4 (Adloff et al 1974). Froelichsporites traversei has been recorded from the Chinle Formation in the SW USA (Arizona, Utah, New Mexico) (Gottesfeld 1972;Dunay and Fisher 1979;Fisher and Dunay 1984;Litwin et al 1991;Reichgelt et al 2013;Lindström et al 2016), Dockum Group (Texas, New Mexico), the Chatham Group (North Carolina) (Litwin and Ash 1993) and the Newark Supergroup (Cornet 1993) (Table 1). It can be considered as a regional biostratigraphy marker of the middle Norian in North America (Litwin et al 1991;Reichgelt et al 2013).…”

Section: Introductionmentioning

confidence: 99%

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Ultrastructure and Probable Botanical Affinity of the Enigmatic SporomorphFroelichsporites traverseifrom the Norian (Late Triassic) of North America

Baranyi

Wellman

Kürschner

2018

International Journal of Plant Sciences

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Premise of research. Froelichsporites traversei is a prominent palynomorph in the Upper Triassic of Northe America which is always occurspermanently found in tetrahedral permanent tetrads. It is an important regional biostratigraphic marker in the Norian ofin North America and its abundance rises around 215 Ma associated with a significant floral and faunal turnover. Its most striking morphological features are the well-developed distal pores (ulci) on each grain and the annulus-like exine thickening around them on each grain. Previous works suggested it was produced by spore-producing plants or Cheirolepidiacea, but its botanical affinity is still unclear.Methodology. The wall ultrastructure of F. traversei was analysed by TEM in order to reveal more information on the botanical affinity of the palynomorph.Pivotal results. The sporoderm consists of two layers and an inner faint discontinuous lamination. The outermost exine layer has homogenous texture (tectum), while the inner layer has granular texture (infratectum). The laminae below the granular layer are not continuous, but directly contiguous with the granules.Conclusions.An explanation for the lack of the well-developed lamellate nexine is that it might represent an immature pollen grain, but the outer layers of the sporoderm, indicates full development. The ultrastructure studies have ambiguous results and, the botanical affinity could not be revealed with certainty, although the most likely candidates are Gnetaeles or Bennettitales based on the wall ultrastructutre. The unusual morphological and ultrastructural features may represent experimentation with angiosperm-related features and functions. The dispersalion as permanent tetrads may have provided probably adaptive advantages to the parent plant of F. traversei related toexplained by polyembryony or polyploidy.3

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“…29), particularly P. chinleana Daugherty (1941) as noted by Stone (1978). Some of it also compares to P. oldhamensis Dunay and Fisher (1978) and P. devolvens Leschik (1955).…”

Section: Comparisons-comparisons To the Type Species Ofmentioning

confidence: 99%

Two new species of the pinnate microsporophyll Pramelreuthia from the upper Triassic of the southwestern United States

Ash

Litwin

1996

American J of Botany

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Two new species of the enigmatic gymnosperm microsporophyll Pramelreuthia, found in the Upper Triassic Chinle Formation at five localities in the southwestern United States, provide significant new evidence on key morphological characters of the genus and extend its known geographical range. These new fossils also demonstrate that the genus was polytypic and reveal the plant megafossil sources for several common and geographically widespread dispersed Upper Triassic microfossil taxa. The genus Pramelreuthia, which until this study was known only from a single specimen from the Upper Triassic of Austria, is a planar pinnate structure consisting of a slender naked axis bearing stalked synangia in opposite to subopposite pairs. Synangia of all three species of Pramelreuthia are oval to subrectangular in lateral view and are composed of two adpressed flattened valves each of which contains up to 20 or more elongate, subcylindrical, tapered sporangia that bear nonstriate bisaccate pollen. Pramelreuthia yazzi sp. nov. is slightly smaller than the type species P. haberfelneri, and its synangia contain pollen generally similar in morphology and size to several species of the dispersed pollen taxon Pityosporites, including P. chinleana, P. oldhamensis, and P. devolvens. Pramelreuthia dubielii sp. nov. is much larger than the other two species; its synangia contain pollen similar to the dispersed pollen species Protodiploxypinus americus.

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Palynology of the Dockum group (Upper Triassic), Texas, U.S.A.

Cited by 44 publications

References 8 publications

Detrital Zircon Link Between Headwaters and Terminus of the Upper Triassic Chinle-Dockum Paleoriver System

Detrital Zircon Link Between Headwaters and Terminus of the Upper Triassic Chinle-Dockum Paleoriver System

Ultrastructure and Probable Botanical Affinity of the Enigmatic SporomorphFroelichsporites traverseifrom the Norian (Late Triassic) of North America

Two new species of the pinnate microsporophyll Pramelreuthia from the upper Triassic of the southwestern United States

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