Vertebrate Taphonomy Applied to the Analysis of Ancient Fluvial Systems

Koster, Emlyn H.

doi:10.2110/pec.87.39.0159

Cited by 18 publications

(11 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Braided channel belt facies amalgamated into thick sandstone packages. The ecological and preservational conditions of this facies tract are generally not conducive to the preservation of vertebrate remains (Koster, 1987), and this holds true in the Ischigualasto Formation.…”

Section: Discussionmentioning

confidence: 99%

Vertebrate taphonomy of the Ischigualasto Formation

Colombi

Rogers

Alcober

2012

Journal of Vertebrate Paleontology

View full text Add to dashboard Cite

ABSTRACT-Trends of preservation are established on the basis of 385 fossil occurrences in the Ischigualasto Formation. The distribution and preservational quality of vertebrate fossils are related to sedimentary facies and stratigraphic position and follow trends in basin evolution and paleoclimate. Fossils in the Ischigualasto Formation are mainly concentrated along the margins of the basin. Floodplain deposits preserve ca. 88% of fossils, which range from unidentifiable fragments to articulated skeletons. The remaining fossil occurrences (ca. 12%) come from coarser-grained fluvial channel deposits and exhibit variable preservational quality, including some well-preserved cynodont skulls. Fossils in the basal La Peña Member (ca. 4% of occurrences) are generally highly weathered and disarticulated with hematitic permineralization. The majority of collected specimens (ca. 65% of occurrences) come from the overlying Cancha de Bochas Member and range from isolated bones to articulated skeletons. Calcite, rather than hematite, is the predominant agent of permineralization. The succeeding Valle de la Luna Member (ca. 30% of occurrences) preserves an association between vertebrate fossils and plant remains. Fossil preservation suggests prolonged exposure prior to burial under wetter conditions with superficial and penetrating precipitation of hematite. The uppermost Quebrada de la Sal Member of the Ischigualasto Formation is nearly barren of fossil remains.RESUMEN-Se establecieron las tendencias en la preservación de restos de paleovertebrados a lo largo de la Formación Ischigualasto en base a 385 fósiles. La distribución y la calidad de preservación de los fósiles de vertebrados en esta unidad está relacionada con las facies sedimentarias y la posición estratigráfica de los mismos, variando según la evolución de la cuenca y del paleoclima. Los fósiles en la Formación Ischigualasto están principalmente concentrados en los márgenes de la cuenca. Paleoambientalmente, los depósitos de llanura de inundación preservan alrededor del 88% de los fósiles de la unidad, los cuales van desde fragmentos inidentificables hasta esqueletos articulados. Las restantes ocurrencias de fósiles (alrededor del 12%) provienen de depósitos de canal de grano grueso y también exhiben variables calidades de preservación, incluyendo algunos pequeños cráneos de cinodontes en excelente estado de preservación. Estratigráficamente, los fósiles en el miembro basal La Peña (alrededor del 4% de los hallazgos) están generalmente muy meteorizados, desarticulados y permineralizados con hematita. La mayoría de los especímenes colectados (alrededor del 65% de los hallazgos) provienen del suprayacente Miembro Cancha de Bochas, los cuales van desde huesos aislados hasta esqueletos articulados completos. Estos restos están permineralizados principalmente con calcita en lugar de hematita. En el siguiente, Miembro Valle de la Luna (alrededor del 30% de los hallazgos), se preserva una peculiar asociación de restos fósiles de vertebrados y plantas. La preservación ...

show abstract

Section: Discussionmentioning

confidence: 99%

Vertebrate taphonomy of the Ischigualasto Formation

Colombi

Rogers

Alcober

2012

Journal of Vertebrate Paleontology

View full text Add to dashboard Cite

show abstract

“…F10 Cross-bedded sandstone Coarse to fine-grained; well-sorted sandstone; poorly consolidated 0Á1 to 1Á0 Tangential foresets 3D dunes (Miall, 1996;Bridge, 2003) (Bridge, 2003), with local bone bed (Behrensmeyer, 1987(Behrensmeyer, , 1988Koster, 1987;Wood et al, 1988). Few developed palaeosols (Retallack, 1988(Retallack, , 2001Hasiotis, 2006) Protected subtidal lagoon in a microtidal regime and rare stormgenerated washover deposits; brackish coastal environment (Flemming, 1988;Anthony et al, 1996;Ford et al, 2007Ford et al, , 2013 (Retallack, 1988(Retallack, , 1997(Retallack, , 2001…”

Section: Fig 5dmentioning

confidence: 99%

Interaction of an antecedent fluvial system with early normal fault growth: Implications for syn‐rift stratigraphy, western Corinth rift (Greece)

et al. 2017

View full text Add to dashboard Cite

Continental ‘overfilled’ conditions during rift initiation are conventionally explained as due to low creation of accommodation compared with sediment supply. Alternatively, sediment supply can be relatively high from the onset of rifting due to an antecedent drainage system. The alluvial Lower Group of the western Plio–Pleistocene Corinth rift is used to investigate the interaction of fluvial sedimentation with early rifting. This rift was obliquely superimposed on the Hellenide mountain belt from which it inherited a significant palaeorelief. Detailed sedimentary logging and mapping of the well‐exposed syn‐rift succession document the facies distributions, palaeocurrents and stratigraphic architecture. Magnetostratigraphy and biostratigraphy are used to date and correlate the alluvial succession across and between fault blocks. From 3·2 to 1·8 Ma, a transverse low sinuosity braided river system flowed north/north‐east to east across east–west‐striking active fault blocks (4 to 7 km in width). Deposits evolved downstream from coarse alluvial conglomerates to fine‐grained lacustrine deposits over 15 to 30 km. The length scale of facies belts is much greater than, and thus not directly controlled by, the width of the fault blocks. At its termination, the distributive river system built small, stacked deltas into a shallow lake margin. The presence of a major antecedent drainage system is supported by: (i) a single major sediment entry point; (ii) persistence of a main channel belt axis; (iii) downstream fining at the scale of the rift basin. The zones of maximum subsidence on individual faults are aligned with the persistent fluvial axis, suggesting that sediment supply influenced normal fault growth. Instead of low accommodation rate during the early rift phase, this study proposes that facies progradation can be controlled by continuous and high sediment supply from antecedent rivers.

show abstract

“…Although a co-occurrence of vertebrate biotas and volcanic activity is not unknown (Lockley and Rice , 1990), vertebrate fossils are most commonly preserved in fluvial and lacustrine settings (Behrensmeyer, 1982;Behrensmeyer et aI., 1992;Koster, 1987) . The preservational environment recorded here may well be unique (Behrensmeyer et aI., 1992;Lockley, 1990) .…”

Section: Geological Setting and Preservationmentioning

confidence: 99%

Depositional environments of a Middle Jurassic terrestrial vertebrate assemblage, Huizachal Canyon, Mexico

Fastovsky¹,

Clark²,

Strater³

et al. 1995

Journal of Vertebrate Paleontology

View full text Add to dashboard Cite

A large assemblage of vertebrate fossils from the La Boca Formation in Huizachal Canyon, near Ciudad Victoria, Tamaulipas, Mexico, is preserved in a unique setting: debris-flow sediments deposited over a landscape with at least modest topographic relief. Angular feldspar lathes in the rock suggest that deposition was associated with penecontemporaneous volcanism. The -8,000-specimen collection from Huizachal Canyon includes the tritylodontid Bocatherium mexicanum, the burrowing diapsid Tamaulipasaurus morenoi, three types of mammals, two crocodyliforms, two types of dinosaurs, a pterosaur, and three sphenodontians. The fossils generally occur as small (-5 mm), isolated bones or bone fragments, but 35 articulated or associated specimens have been found . No turtles or fishes have been identified, implying a terrestrial source for this assemblage. Biostratigraphic and preliminary radiometric evidence suggest an early Middle Jurassic age, making this assemblage the only substantial terrestrial Middle Jurassic vertebrate fauna known from North America.ABSTRACTO-Una coleccion grande de vertebrados fosiles recuperados en la Formacion La Boca, expuesta en el Canon del Huizachal, en las inmediaciones de Ciudad Victoria, Tamaulipas, Mexico, se encuentra conservada en un ambiente singular, constituido por sedimentos de flujo de escombro depositados sobre una paleotopografia de relieve modesto. Fragmentos angulares de feldespato en la roca , sugieren que el deposito estuvo asociado a vulcanismo penecontemporando. Los -8,000 especimenes colectados en el Canon del Huizachal incluyen el tritilodontido Bocatherium mexicanum, el diapsido cavador Tamaulipasaurus morenoi, tres tipos de mamiferos, dos formas de cocodrilos, un pterosaurio y tres clases de esfenodontes. Los fosiles son generalemente huesos fragmentados 0 aislados de talla pequefia (-5 mm), sin embargo, se ha encontrado 35 especimenes articulados 0 asociados. No han sido identificados tortugas 0 peces, 10 que sugiere que la fuente de deposito es terrestre. Las evidencias bioestratigraficas y la radiometria preliminar sugieren una edad jurasica media temprana, con 10que esta fauna de vertebrados continentales constituye la (mica asociacion bien establecida para el Jurasico Medio de America del Norte.

show abstract

Vertebrate Taphonomy Applied to the Analysis of Ancient Fluvial Systems

Cited by 18 publications

References 0 publications

Vertebrate taphonomy of the Ischigualasto Formation

Vertebrate taphonomy of the Ischigualasto Formation

Interaction of an antecedent fluvial system with early normal fault growth: Implications for syn‐rift stratigraphy, western Corinth rift (Greece)

Depositional environments of a Middle Jurassic terrestrial vertebrate assemblage, Huizachal Canyon, Mexico

Contact Info

Product

Resources

About