摘要:

Leaves assignable toNothofagusfrom two fossil deposits in Tasmania represent the first macrofossils of this genus from the Tertiary in southeastern Australia. One fossil species,N. johnstonii, is closely related to the extant Australian speciesN. cunninghamiiwhile the other fossil species,N. tasmanica, has very close affinites with the extant Australian speciesN. moorei. All four of these species are closely interrelated. The pollen type produced by the fossil species is unknown, since all three types are present in the microfloras. However, bothN. cunninghamiiandN. mooreiproduceN. menziesii-type pollen. The macrofossils confirm the conclusion from pollen studies that evolution inNothofagushas occurred very slowly.

ISSN:0311-5518    

DOI:10.1080/03115518308619616

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

A new species ofBanksia, B. archaeocarpa, from the Merlinleigh Sandstone, Kennedy Range, Western Australia is described on the basis of fossilised fruiting bodies (infructescences). An additional single, incomplete, sterile inflorescence ofBanksiais also described, but not formally named. Marine fauna present in the sandstones along with the plant material has allowed dating of the Merlinleigh Sandstone as Middle or Late Eocene. The presence ofBanksiaremains in rocks of this age in Western Australia represents the earliest unequivocal occurrence ofBanksiain Australia. The infructescences are superficially very similar to some present day Western Australian species ofBanksia. This suggests that the genus was morphologically well established by the Late Eocene.

ISSN:0311-5518    

DOI:10.1080/03115518308619617

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

A small millipede with distinctive tergal ornament is described from the Westgrove Ironstone Member in the upper part of the Early Jurassic Evergreen Formation in the Surat Basin, Queensland. Its taxonomic placement within the class is uncertain at present as the species displays characters of two orders and is incompletely known. It is the first description of fossils of the class Diplopoda from Australia. The material, consisting of two poorly preserved incomplete individuals is described asDecorotergum warrenaegen. et sp. nov.

ISSN:0311-5518    

DOI:10.1080/03115518308619618

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

ISSN:0311-5518    

DOI:10.1080/03115518308619620

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Proximal development of the dichograptoid rhabdosome is re-examined in detail. Two major types are recognised: the artus type (= dichograptid type of Bulman) in which th 11is dicalycal, and the isograptid type (= isograptid + leptograptid types of Bulman) in which theca 12is dicalycal. In branching dichograptids, distal stipe division takes place by replication of the thecal budding sequence employed in the initial dichotomy of the rhabdosome and is always of isograptid type. Dichotomies beyond the first are unknown in species with initial development of other than isograptid type. The thecal budding pattern and stipe composition of dendroids can be interpreted in terms of the structure of, and thecal notation used for, graptoloids and it is thus possible to compare directly the mode of stipe division in the two groups. It is found that both distal and proximal dichotomy in dendroids are achieved by a pattern of thecal budding closely comparable with that of the isograptid type of division in graptoloids. The isograptid development type is therefore thought to have been directly derived from dendroids, and is the primitive type for Graptoloidea. The artus type was derived via three or more independent lineages, at least one of which (that leading to theartusgroup of pendent didymograptids) involved an ancestor with isograptid development. Proximal end characters ofPhyllograptussuggest that this genus and biserial graptolites of the family Diplograptidae shared a common ancestor.

ISSN:0311-5518    

DOI:10.1080/03115518308619621

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

One new species ofPhillipsia (P. squamata)and four new species ofWeberiphillipsia (W. osmolskae, W. robertsi, W. girvanensisandW. altoculata)plusW. collinsi(Mitchell) are described from the late Tournaisian-Visean strata of eastern New South Wales. All species share the cephalic features of a long, gently-waisted glabella reaching or partly overhanging the anterior border; isolated pre-occipital lobes; long crescentic eyes and dense nodose ornament. Most features remain stable except for an anterior shift of the highest point of the glabella and a change from outwardly crescentic to near vertical, very tall eyes which are concealed from the dorsal view. Pygidia have a phillipsiid-form with segments exhibiting a sawtooth profile and a row of nodes along their high posterior edge. Over the group, the ring count drops marginally from 14 + to 13 but the rib count drops markedly, by post-axial contraction, from 12 to 7. Both rings and ribs are aligned anteriorly with the ribs curving progressively backwards to become sub-parallel to the axis.P. squamatahas no border but the ribs stop short of the edge leaving a narrow smooth margin. InWeberiphillipsiaspp. a border is developed on to which the ribs continue as low ridges. Nodes on these border ribs become coarser and fewer, being reduced to one in the last species. As the rib count drops, the border ornament becomes detached and slightly rotated from the ribs, accumulating as a cluster of fading, post-axial nodes. Concurrently, the ornament recedes from the outer margin leaving a smooth outer half on the border. In the final species, a second false border appears outside the ornament which then appears as a detached, offset part of the pleural rib. Over the five species, both axial and pleural nodes decline in number from 13 to 4, combined with a corresponding increase in size. The stratigraphic distribution of this evolutionary development is detailed.

ISSN:0311-5518    

DOI:10.1080/03115518308619622

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor