摘要:

The Cambrian trace fossilPlagiogmusis the floor of a backfilled burrow which is common in the deltaic sediments of the Arumbera Sandstone in central Australia. ThePlagiogmusforming organism/s was/were connected to the surface by a siphon that formed a longitudinal furrow. Collapse associated with the movement of the siphon through the sediment may have produced a variety of trace fossil morphologies similar to the ichnogeneraGordia, CochlichnusandTaphrhelminthopsis. Other parts of thePlagiogmusburrow may be compared withOlivellites, Aulichnites, Laminites, ClimactichnitesandPsammichnitesispp. The distinctive transverse bars of thePlagiogmusstructure are interpreted as being produced by a posterior sucker used by the animal during locomotion. It is interpreted that the burrow fill was composed solely of feeding wastes and not the spoils of tunnelling. The laminae within the backfill are not related to the transverse bars. Bilobed burrows overlying thePlagiogmuscomponent are related to the presence of a siphon that we interpret to have been used in surface deposit feeding. The biological affinities of thePlagiogmus-forming animal remain obscure, but it was probably vermiform and shared characters with the Mollusca, Annelida, Hirundinea and/or some echinuran worms.

ISSN:0311-5518    

DOI:10.1080/03115519708619171

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Two species of brachiopod are recorded from the Upper Cambrian Chatsworth Limestone of western Queensland.Kozhuchinella, previously only known from supposed Upper Tremadoc rocks of southwest Siberia, is documented for the first time from Australia asKozhuchinellacf.mariinicaSevergina, 1967. This species exhibits digitate ventral and dorsal mantle canal systems, the latter unusual in possessing blind vascula myaria. The musculature and mantle canal systems indicate that the species belongs to the Billingsellidae and not the Plectambonitoidea as originally suggested by Severgina. Also documented is a new genus,Radkeina(type speciesR. taylorisp. nov.), tentatively assigned to the Family Huenellidae.

ISSN:0311-5518    

DOI:10.1080/03115519708619172

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The Hunter Siltstone near Grenfell, New South Wales, contains a rich Upper Devonian fish fauna including the sinolepidGrenfellaspisand the new antiarchsBothriolepis grenfellensissp. nov. andRemigolepis redcliffensissp. nov.Bothriolepis grenfellensissp. nov. is the first bothriolepid species described from N.S.W., andR. redcliffensissp. nov. is the first species ofRemigolepisdescribed from Australia. Traditionally, the Hunter Siltstone was considered to be uppermost Famennian or earliest Carboniferous in age based on the presence ofGrenfellaspis, and the related taxonSinolepis, which is known from the Wutung and Sanmentan formations of southeastern China. However, available data indicates the Hunter Siltstone may be early Famennian in age. Ongoing work suggests that all FamennianBothriolepisfrom N.S.W., includingB. grenfellensis, possess a trifid preorbital recess, but differ in other aspects of headshield morphology. In North China, the Famennian Zhongning Formation contains six species ofRemigolepisand a species ofSinolepis. However,R. redcliffensisdoes not show any similarity to these species beyond those ofRemigolepisas a whole.

ISSN:0311-5518    

DOI:10.1080/03115519708619173

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

ISSN:0311-5518    

DOI:10.1080/03115519708619174

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Belemnites are nektopelagic cephalopods which developed a widespread pattern of distribution in the Jurassic, and most authors have accepted that their centre of origin was Europe. Available data suggest that the belemnites developed a global distribution only in the Toarcian, some 15 Ma after their first appearence in the European Hettangian. Development of the Boreal and Tethyan belemnite realms took place in the Middle Jurassic and continued through to the Cretaceous. New data from Argentina and the Antarctic Peninsula reaffirms the development of the global distribution of belemnites in the Toarcian, and sheds new light on the biogeographical patterns for the Jurassic of the southern hemisphere. This has considerable implications for understanding the development of faunal realms in the Mesozoic.

ISSN:0311-5518    

DOI:10.1080/03115519708619175

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Foraminifea from the type section of the Giralia Calcarenite indicate an upper zone P12 correlation and a Middle Eocene age (probably within the interval 41.5–40.5 Ma, BKSA95 time scale). The type Giralia Calcarenite is considered to represent one sequence (with maximum thickness of 40–50 m preserved on the Gascoyne Platform) and to reflect late transgressive and early highstand deposition about a maximum flooding event. Initial retrogradation of the shoreline produced a maximum water depth of about 50 m at the type locality (5–6 m above base of stratigraphic section). The formation may correlate with shallow marine deposits found elsewhere in the Southern Carnarvon Basin (e.g. Eocene limestones at Yaringa and Red Bluff, and the Merlinleigh Sandstone), and correlates with Middle Eocene transgressive units in the Perth, Eucla, Great Australian Bight and Otway Basins.

ISSN:0311-5518    

DOI:10.1080/03115519708619176

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor