摘要:

Two new stromatolites,Ephyaltes edingunnensisandEucapsiphora leakensis, are described from the Palaeoproterozic Earaheedy Group, in the Earaheedy Basin (formerly the eastern part of the Nabberu Basin), Western Australia. In addition, new localities are reported forAsperia digitatacomb. nov. (=Yelma digitataGrey 1984),Pilbaria deverellaGrey 1984, andYandilla meekatharrensisGrey 1984 from problematic successions in the adjacent Glengarry Basin (formerly the western part of the Nabberu Basin), confirming correlation of these rocks with the base of the Earaheedy Group. Four of the five groups recorded,Asperia, Eucapsiphora, EphyaltesandPilbaria, are known from outside the Earaheedy Basin and their stratigraphic age is consistent with the probable minimum 1.65 Ga age of the Earaheedy Group. However, none of the forms has yet been recorded from outside the Earaheedy Group.

ISSN:0311-5518    

DOI:10.1080/03115519408619495

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The extent of racemisation for a range of amino acids for the total acid hydrolysate and free fractions, calibrated against radiocarbon dating, indicates that the foraminiferMarginopora vertebralis, found within ‘modern’ tidal flat sediments between Wardang Island and Goose Island, South Australia, is reworked from the underlying Late Pleistocene Glanville Formation. Analyses of amino acids in the total acid hydrolysate and free fractions in conjunction with the determination of absolute concentrations of amino acid residues in fossils, provides an elegant method for assessing the validity of amino acid racemisation dating, and in identifying reworked fossils.

ISSN:0311-5518    

DOI:10.1080/03115519408619496

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A fossil bone deposit from a cliff flanking the Tiropahi River, Westland, South Island, New Zealand, was dated at 17,340 ± 140 radiocarbon years BP. The taphonomy suggests that the deposit was accumulated by a predator. Site characteristics, prey size and bone damage patterns (greenstick fractures and evidence of digestion) suggest the predator was the extinct or near-extinct Laughing OwlSceloglaux albifacies. The species assemblage represented by the fossils show thatSceloglauxwas an opportunistic predator whose diet included birds, bats, frogs, skinks, geckos, and fish. The dominant prey were nocturnal ground-frequenting birds, particularly shearwaters and prions. The preferred habitats of the prey species and the deposit's age suggest that the river valley near the fossil site was forested, with areas of shrubland and grassland, during the coldest part of the Otiran Glaciation.

ISSN:0311-5518    

DOI:10.1080/03115519408619497

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Natural casts of seven small footprints have been identified on a single weathered block derived from the Precipice Sandstone (Lower Jurassic) of the Carnarvon Gorge, southeastern Queensland. The footprints are attributed to ornithopod dinosaurs and are referred to the ichnogenusAnomoepus. They appear to be most similar to the ichnospeciesAnomoepus gracillimus, originally defined on footprints from the Lower Jurassic of the northeastern United States. This identification is consistent with the presumed age of the Precipice Sandstone, sinceAnomoepusor closely related ichnotaxa are common in Lower Jurassic sediments of the United States, Europe and southern Africa but have never been identified with certainty in Triassic sediments. The tracks described here were made by at least four dinosaurs, all estimated to have been about 30 cm high at the hip and less than 1·3 m in total length. In their general appearance these animals probably resembled the small plant-eating dinosaurFabrosaurus(Lesothosaurus), from the Lower Jurassic of southern Africa. Tracks of two animals provide estimates of walking speeds between 0·68 and 0·80 m/s (2·4 and 2·9 km/h). These footprints are the earliest evidence for the existence of ornithischian dinosaurs in Australia.

ISSN:0311-5518    

DOI:10.1080/03115519408619498

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Mammal (marsupial) palaeontology is useful for the correlation of non-marine strata of Australia and New Guinea. The geochronological framework constructed from marsupial data is based substantially in stage-of-evolution biochronology, which is not subject to the formal guidance of a code, or regulation by an authority. Instead, it has evolved through an informal consensus of usage. Principles and practices of stage-of-evolution biochronology and its historical development are reviewed from an Australian perspective. Amongst more recent developments in the discipline are the establishment of the first marsupial biostratigraphy for the continent, covering the Etadunna Formation of the Lake Eyre Basin (Woodburneet al., 1993), and the introduction of novel terminology to express marsupial succession in the Carl Creek Limestone of northwestern Queensland (Archeret al., 1989). The merits of the various approaches to biochronology are examined: stage-of-evolution biochronology has provided, and will continue to contribute to, a correlation framework for a continent with a sparse mammal record not generally amenable to biostratigraphic resolution. Terminology proposed by Archeret al.(1989) is shown to be unsatisfactory.

ISSN:0311-5518    

DOI:10.1080/03115519408619499

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor