ISSN:1042-0940    

DOI:10.1080/10420949209380070

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Several morphological varieties of trace fossils abound in Middle and Late Triassic fluvial redbeds in the Pranhita‐Godavari Valley, south India, includingSkolithos, Palaeophycus, Taenidium, escape burrows, and a type of trace very similar to ‘small stuffed burrows’ from the Triassic of Greenland. Burrow morphology was influenced by local hydrodynamic conditions. The distribution of burrows was facies controlled; some forms are restricted to channel deposits whereas others occur only in floodplains. Vertical dwelling burrows(Skolithos)occur in both channel and floodplain deposits. Horizontal structures representing deposit feeding(Taenidium)are confined to nondepositional surfaces within parallel‐laminated sandstones having parting lineations that represent catastrophically emplaced sand‐sheets in channels and proximal floodplains. Vertical escape burrows are confined to what were slowly but continually accreting parallel‐laminated sands of channel bars. Horizontal dwelling burrows(Palaeophycus)and ‘small stuffed burrows’ are virtually restricted to the smaller sandsheets of floodplain drainage systems.

ISSN:1042-0940    

DOI:10.1080/10420949209380071

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Nonmarine strata of the Lower Carboniferous Albert Formation of southern New Brunswick, eastern Canada, contain relatively diverse and abundant invertebrate trace fossils comprising twelve ichnogenera, fourteen ichnospecies, and one vernacular ichnotaxon. These traces occur in two mutually exclusive, spatially and temporally recurrent ichnocoenoses, each related to specific paleoenvironments. TheRusophycusichnocoenosis characterizes upper portions of upward‐fining fluvial channels and comprises ichnotaxa reflecting different behavioral activities of arthropods. ThePalaeophycusichnocoenosis characterizes shallow lacustrine sequences and comprises ichnotaxa produced essentially by deposit‐feeding invertebrates, possibly annelids (?oligochaetes). Exclusion of ichnofaunas from strata of additional and similarly intergradational paleo‐environmental regimes within the sequence (alluvial fan, alluvial plain, algal swamp, deep lacustrine, evaporitic lacustrine) is suggested to reflect several physical environmental constraints, notably parameters such as grain size, availability of nutrients, and oxygen and salinity levels.

ISSN:1042-0940    

DOI:10.1080/10420949209380072

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A series of six problematical and controversial footprints at Clayton Lake State Park, New Mexico, described as a supposed pterosaur trackway were reexamined to determine what sort of animal made them and how they were made. Additional footprints and two tail drags were found. These, together with some of the six problematical footprints, form at least three trackways of crocodylomorph animals, probably crocodilians. The trackways were probably formed in shallow water and may record the transition from walking to swimming.

ISSN:1042-0940    

DOI:10.1080/10420949209380073

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Hardgrounds from the bathyal Mediterranean represent conditions of low net sedimentation and progressive cementation. Trace fossils preserved in the cemented crusts document the change in substrate consistency from softground through firmground to hardground. The studied material was dredged from stations at water depths of about ‐600 m to ‐4100 m. Trace fossils of theGlossifungitesandTrypanitesichnofacies are well represented. The most important forms present are softgroundChondritesisp., firmgroundSpongeliomorphacf.S. ibericaandGlossifungites saxicava, the agglutinated tube"Terebella” phosphaticaencrusting hardgrounds, and the hardground boringsEntobiaisp.,?Maeandropolydoraiisp.,?Caulostrepsisisp., and three microborings attributed to fungi.

ISSN:1042-0940    

DOI:10.1080/10420949209380074

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

An Eocene kaolin deposit in Georgia contains microspheres of tangentially oriented kaolinite enclosing authigenic cristobalite/tridymite overgrown with kaolinite. These structures resemble cutans of clay minerals that surround polysaccharide‐covered bacteria in recent soils and sediments. Bacteria actively synthesize anionic mucopolysaccharides as adhesives for attachment to surfaces. Empty cutans are common; these polymer‐bound clay mineral microspheres persist following cell death and lysis. Even though the void space thus created and associated organic material influence subsequent diagenetic changes, sedimentary microfabrics attributable to bacterial activity are preserved.

ISSN:1042-0940    

DOI:10.1080/10420949209380075

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A sequence of Lower Ordovician (Arenig) turbidites in Co. Wexford, Eire, has yielded one of the earliest diverse ichnofaunas yet recorded from deep water sediments comprising:Chondrites, Glockerichnus, Gordia, Helminthopsis, Lorenzinia, Neonereites, Palaeophycus, Paleodictyon, Planolites, Sublorenzinia, Taenidium, Taphrhelminthopsis, TeichichnusandTomaculum. This ichnofauna is critical in any analysis of the colonisation of the deep seas by trace fossil‐producing animals.

ISSN:1042-0940    

DOI:10.1080/10420949209380076

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Dinosaur tracks

ISSN:1042-0940    

DOI:10.1080/10420949209380078

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Palaxius salataensis, an anomuran microcoprolite, is described from Cretaceous deposits of the MIT Guyot in the northwest Pacific, about 1500 km southeast of Japan. This is the first report of the ichnogenus in this area and the first report of the ichnospecies in Cretaceous deposits. The range ofP. salataensisis thus very long, from Permian to Cretaceous.

ISSN:1042-0940    

DOI:10.1080/10420949209380077

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:1042-0940    

DOI:10.1080/10420949209380079

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor