Spiriferids are abundant in the Permian faunas of eastern Australia and all of the currently known species are discussed in this thesis. Eastern Australian Permian spiriferid species belong to 13 genera distributed amongst seven sub-families. The puncta genera Pseudosyrinx Weller, Subansiria Sahni and Srivastava, and Punctospirifer North are each represented by several species. Subansiria occurs in the Permian faunas of Queensland, New South Wales, and Tasmania, but Pseudosyrinx is as yet unrecorded from the Tasmanian Permian, and Punctospirifer is at present known only from Queensland. In comparison with its overseas occurrences the unusual Permian spiriferid Attenuatella Stehli is rather common in eastern Australia. Five species of Attenuatella are distinguished and serial sections of one of these, Attenuatella convexa sp. nov., pisDvide additional data about the brachial skeleton of the genus. Grantonia Brown is now believed to be a synonym of Trigonotreta Koenig. The relationship between Trigonotreta and Neospirifer Fredericks is discussed. It is also suggested that Cancellospirifer maxwelli Campbell, the type species of Cancellospirifer Campbell, may comprise juvenile individuals of a species of Trigonotreta. Other trigonotretin genera to which some of the eastern Australian Permian spiriferids belong are Fusispirifer Waterhouse and Sulciplica Waterhouse. Martiniacean genera represented in the eastern Australian Permian are Martinia McCoy, Notospirifer Harrington, and Inaelarella Campbell. The new generic name Murella (type species, M. ulladullensis sp. nov.) is proposed for three distinctive martiniacean species; Murella is grouped with Notospirifer and Ingelarella in the Ingelarellinae.
Previously proposed classifications of the Spiriferidina are briefly reviewed and the subfamilial categories adopted in this thesis are discussed.
Three morphological aspects of the spiriferids described herein warrent particular mention. Pallial markings are moderately well preserved on some specimens of Subansiria, Trigonotreta, Sulciplica, Martinia, Notospirifer, and Ingelarella. and these are described and discussed. Fragmentary delthyrial covers occur on a specimen of Trigonotreta and on a specimen of Sulciplica. The fragment in the delthyriura of the former specimen has features in common with the symptidial plates which occur in the delthyrium of Mucrospirifer. The characteristics of the microornament of some species of Notospirifer appear to be unique amongst spiriferids. The micro-ornaments of the species of Notospirifer are examined and they are compared with the micro-ornamental and punctal characteristics of two of the species here included in Subansiria. Articulate brachiopod shells are opened by diductor muscles and some of the parameters which- govern the movement of one valve of the articulate brachiopod shell with respect to the other are also analysed.
The microstructural components of the shells of four spiriferids, one terebratulid, one productid, and one strophomenid have been examined with the aid of an electron microscope. It is apparent that fundamentally different types of microstructural components comprise the shells of the different articulate brachiopod orders. The studied shells of the spiriferids and of the terebratulid consist of readily distinguishable primary and secondary layers. The latter layer consists of fibres inclined obliquely forwards into the shell from the inner surface of the primary layer. No primary layer was detected on the shells of Streptorhynchus pelicanensis Fletcher (Strophomenidina, Davisoniacea) and Terrakea solida (Etheridge and Dun; Productidina, Productacea). Moreover the shells of these species consist of tabular components (herein termed blades) which are arranged in sheets parallel to the surface of the shell. Blades within a sheet are parallel to each other but are not parallel to the blades in the contiguous underlying and overlying sheets. Pseudopunctae penetrate the shell of T. solida but punctae occur in the shell of S. pelicanensis.
The stratigraphic occurrences of the spiriferids described herein lend support to correlations of the Permian faunas delineated in eastern Australia by Drs J.M. Dickins and B.N. Runnegar. The distributions of some of the genera may have palaeogeographical implications.