Middle Ordovician (Darriwilian) conodonts from the Goldwyer Formation of the Canning Basin,Western Australia

Zhen, Y.Y., Normore, L.S., Dent, L.M. & Percival, I.G., 11 July 2019. Middle Ordovician (Darriwilian) conodonts from the Goldwyer Formation of the Canning Basin, Western Australia. Alcheringa 44, 25–55. ISSN 0311-5518

Middle Ordovician conodonts attributed to 46 species were recovered from a stratigraphic interval spanning the Willara, Goldwyer and Nita formations in core sections from the Sally May-2 and Theia-1 petroleum exploration wells in the Canning Basin, Western Australia. The Histiodella serrata, Histiodella holodentata and Eoplacognathus pseudoplanus biozones are recognized in the lower and middle part of the Goldwyer Formation, indicative of an early–middle Darriwilian age. This revised conodont biostratigraphy enables more precise correlation with North America and North and South China. Several biogeographically distinctive conodont species, most likely of North Chinese origin, are recorded from the Goldwyer Formation. Their presence signals a strong palaeobiogeographic connection between the Sino-Korean Craton and the Canning Basin on the western margin of eastern Gondwana during the late Middle Ordovician.

Y.Y. Zhen* [yong-yi.zhen@planning.nsw.gov.au], W.B. Clarke Geoscience Centre, Geological Survey of New South Wales, 947–953 Londonderry Road, Londonderry NSW 2753, Australia; L.S. Normore [leon.normore@dmirs.wa.gov.au]; L.M. Dent [louisa.dent@dmirs.wa.gov.au], Department of Mines, Industry Regulation and Safety, Mineral House, Geological Survey of Western Australia, 100 Plain Street, East Perth, WA 6004, Australia; I.G. Percival [ian.percival@planning.nsw.gov.au], W.B. Clarke Geoscience Centre, Geological Survey of New South Wales, 947–953 Londonderry Road, Londonderry NSW 2753, Australia;     

Late Devonian gastropods from the Canning Basin,Western Australia

Over 50 identifications of Tertiary pollen are reviewed. The pollen assemblages indicate rain-forest through most of the Tertiary, but the requisites for pollen preservation are biased towards the wetter climates.

The present day geographical affinities of the botanical groups are largely with taxa of the tropical zone and Australia-wide taxa. There is geographic variation in the fossil pollen assemblages when southeastern Australia is compared with Central Australia and Queensland.

The major changes in the fossil floras coincide with climatic change, indicating the influence of climate on the evolution of plant assemblages. The older phytogeographic concepts are inappropriate for the fossil record, especially when considered in conjunction with palaeoclimates and palaeogeography.

It is unfortunate that palynology has given little information of the evolution of floras in drier climatic regimes, or of the evolution of the eucalypts.     

Cainozoic euphorbiacean wood from the Canning Basin,Western Australia

A new species of fossil wood is described, Bridelioxylon canningense Bamford & McLoughlin, belonging to the Phyllanthoideae group of the Euphorbiaceae. The woods occur in indurated sandstones and conglomerates preserved in palaeochannels incised into the Upper Permian Condren Sandstone in the Landrigan Cliffs, northern Canning Basin, Western Australia. Based on the presence of the dicotyledonous woods and the geomorphological setting of the palaeochannel, a Palaeogene age is suggested for the host rocks. This is the first record of fossil euphorbiacean wood in Australia; pollen has been previously recorded. The fossil wood is most closely comparable to extant members of Bridelia that currently occupy the warmer and wetter parts of Australia.     

Middle Ordovician (Darriwilian) conodonts from allochthonous limestones in the Oakdale Formation of central New South Wales

The Dansirit Formation of the Shemshak Group is well exposed in the Parvar area, near the Rudbarak village, Central Alborz, Iran. It contains abundant well-preserved plant macrofossils belonging to 20 taxa of Equisetales, Marattiales, Filicales, Bennettitales, Cycadales, Corystospermales, Caytoniales, Czekanowskiales, Ginkgoales and Pinales. The new species Caytonia iranica sp. nov. is described. Based on the occurrence of Equisetites beanii, Coniopteris hymenophylloides, Nilssonia sarakhs, Czekanowskia blacki and Pseudoctenis fragilis, an early Middle Jurassic age is suggested for this assemblage.     

Ordovician acritarchs from the Canning Basin,Western Australia

A left mandibular toothplate of a chimaeroid fish collected from the Toolebuc Formation (Early Cretaceous, Albian), central Queensland is described. Comparisons with other chimaeroid genera show the toothplate to be sufficiently distinct to warrant the erection of a new genus. Ptyktoptychion tayyo gen. et sp. nov. is distinguished by the size and shape of its three tritors, the form of the symphysial facet and the overall shape of the toothplate.     

Middle Ordovician brachiopods from the Stairway Sandstone,Amadeus Basin,central Australia

Jakobsen, K.G., Brock, G.A, Nielsen, A.T., Topper, T.P. & Harper, D.A.T., 2013. Middle Ordovician brachiopods from the Stairway Sandstone, Amadeus Basin, central Australia. Alcheringa. ISSN 0311–5518.

Middle Ordovician brachiopod faunas from the Amadeus Basin, central Australia are poorly known. The Darriwilian Stairway Sandstone was sampled stratigraphically for macrofossils in order to provide new information on marine benthic diversity in this clastic-dominated, shallow-water palaeoenvironment along the margin of northeastern Gondwana. The brachiopods from the Stairway Sandstone are of low diversity and represent ca 9% of the entire shelly fauna. Five brachiopod taxa are described from the Stairway Sandstone; all are endemic to the Amadeus Basin at species level. Two new species, Amadeuphyla joanae gen. et sp. nov. and Paralenorthis luritjaorum sp. nov., are described. Unweighted cladistic analysis based on 20 characters places the new genus Amadeuphyla within the Taffinae.

Kristian G. Jakobsen [kgjakobsen@snm.ku.dk] Geological Museum, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5–7, DK-1350 Copenhagen, Denmark & Department of Biological Sciences, Macquarie University, New South Wales 2109, Australia. Glenn A. Brock [glenn.brock@mq.edu.au] Department of Biological Sciences, Macquarie University, New South Wales 2109, Australia. Arne T. Nielsen [arnet@snm.ku.dk] Geological Museum, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5–7, DK-1350 Copenhagen, Denmark. Timothy P. Topper [timothy.topper@snm.ku.dk] Geological Museum, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5–7, DK-1350 Copenhagen, Denmark. David A. T. Harper [david.harper@durham.ac.uk] Geological Museum, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5–7, DK-1350 Copenhagen, Denmark & Department of Earth Sciences, Durham University, Durham, UK. Received 14.6.2013; revised 25.9.2013; accepted 8.10.2013.     

Ordovician biostratigraphy of the Canning Basin,Western Australia

Six biostratigraphically distinct faunas based largely on trilobites and graptolites are defined from the Lower to Middle Ordovician limestone, sandstone and shale sequence of the Canning Basin. They range in age from the Tremadoc (fauna 1), through the Arenig (faunas 2, 3) to the Llanvirn (faunas 4–6).     

Neoproterozoic microfossils from the Officer Basin,Western Australia

Microfossil assemblages are described from the early Neoproterozoic Madley and Browne Formations, western Officer Basin. One chert and eleven siliciclastic samples yielded microfossils. Myxococcoides cantabrigiensis occurs as pustular mats in the chert sample and Eomicrocystis malgica, Pterospermopsimorpha granulata, Skiagia sp. cf. S. pusilla, and undetermined species of Obruchevella, Heliconema, and Trachystrichosphaera are present in acid macerated samples. Leiosphaeridia spp. and Siphonophycus spp. are also found in fine-grained siliciclastic samples, with clusters of Synsphaeridium sp. in some samples. These findings enable a more substantial reconstruction of the palaeoenvironment of Supersequence 1 in the western Centralian Superbasin. The acanthomorph acritarchs are considered to be planktonic eucaryotes washed into environments which ranged from coastal sabkha through to tidal flats, which may be the source of the prokaryotic, benthic, matforming cyanobacteria.     

Microfossils from Neoproterozoic Supersequence 1 of the Officer Basin,Western Australia

The discovery of a rich assemblage of microfossils from the Neoproterozoic western Officer Basin (Centralian Superbasin) provides a more complete understanding of the biostratigraphy of this Basin. The microfossils are found in Supersequence 1 (～800 Ma) in Western Australia. The assemblages are comprised of acritarchs and cyanobacteria isolated by acid maceration from siliciclastics of the Browne (Madley), Hussar, Kanpa and Steptoe Formations. The distinctive acritarchs Cerebrosphaera buickii, Satka colonialica, Stictosphaeridium sinapticuliferum and Pterospermopsimorpha insolita are of particular interest in the Neoproterozoic. These taxa are found in similar depositional environments in Spitsbergen, Arizona, Canada and Siberia. This evidence, together with lithostratographic correlations, isotope chemostratigraphy, and sequence analysis contributes to the continuing development of Neoproterozoic stratigraphy.     

Middle Ordovician (early Dapingian) conodonts in the Central Andean Basin of NW Argentina

Carlorosi, J., Heredia, S. & Aceñolaza, G, 2013. Middle Ordovician (early Dapingian) conodonts in the Central Andean Basin of NW Argentina. Alcheringa 37, 1–13. ISSN 0311-5518.

This paper describes and analyzes the significance of a conodont fauna from the Alto del Cóndor Formation, exposed in the Los Colorados region of the Argentine Eastern Cordillera. Identified taxa are Baltoniodus triangularis, Baltoniodus sp. cf. B. triangularis, Drepanodus sp., Drepanoistodus basiovalis, Drepanoistodus sp. B., Erraticodon patu, Gothodus costulatus, Oistodus sp., Trapezognathus diprion, T. quadrangulum, Triangulodus sp. and Triangulodus? sp. The presence of Baltoniodus triangularis indicates the base of the Dapingian stage (Middle Ordovician). In addition, we report the coexistence of T. diprion and T. quadrangulum. The conodont association suggests a faunal affinity with Baltica and South China, both belonging to the Shallow-Sea Realm of the Temperate-Cold Domain.

Josefina Carlorosi [josefinacarlorosi77@gmail]com], INSUGEO—Universidad Nacional de Tucumán—CONICET, Miguel Lillo 205, (4000) Tucumán, Argentina; Guillermo F. Aceñolaza [acecha@webmail.unt.edu.ar], Universidad Nacional de Tucumán—CONICET, Miguel Lillo 205, (4000) Tucumán, Argentina; Susana Heredia [sheredia@unsj.edu.ar], CONICET–CIGEOBIO and Instituto de Investigaciones Mineras, Facultad de Ingeniería, Universidad Nacional de San Juan, Urquiza y Libertador, (5400) San Juan, Argentina. Received 22.8.2012; revised 18.10.2012; accepted 24.10.12.     

First record of the trace fossil Protovirgularia from the Middle Permian of southeastern Gondwana (southern Sydney Basin,Australia)

LUO, M. &; SHI G.R., February 2017. First record of the trace fossil Protovirgularia from the Middle Permian of southeastern Gondwana (southern Sydney Basin, Australia). Alcheringa 0, 000–000. ISSN 0311-5518.

This study reports the first examples of well-preserved chevronate trails referable to Protovirgularia longespicata De Stefani, 1885 Stefani, DE.C., 1885. Studi paleozoologici sulle creta superiore e media dell' Apennino settentionale. Atti della Reale Accademia dea Lincei, Memorie 22, 101?134. [Google Scholar] from the early Middle Permian (Roadian) upper Wandrawandian Siltstone of the southern Sydney Basin, southeastern Australia. The highly meandering trace with closely spaced, papillate chevrons is interpreted to have been produced by the locomotion-feeding behaviour of certain protobranch bivalves in an offshore environment. The dense trails occurring on the upper bedding planes of pebbly siltstone may represent a gregarious lifestyle, where junior and senior individuals of the trace-maker bivalves coexisted while moving within sediments. The Wandrawandian Protovirgularia also represents the first known occurrence of this ichnotaxon from a glaciomarine environment in the Permian eastern Gondwana. The global record of Protovirgularia occurrences suggests that these trails had a wide environmental distribution since the Cambrian, and there is no obvious difference in the environmental distribution of Protovirgularia after the Permian?Triassic transition.

Mao Luo [m.luo@deakin.edu.au] and G.R. Shi [guang.shi@deakin.edu.au], Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood Campus, 221 Burwood Highway, VIC 3125, Australia.     

Terminal Cambrian and Early Ordovician (Tremadocian) conodonts from Eastern Alborz,north-central Iran

Hadi Jahangir, Mansoureh Ghobadi Pour, Alireza Ashuri & Arash Amini, December 2015. Terminal Cambrian and Early Ordovician (Tremadocian) conodonts from Eastern Alborz, north-central Iran. Alcheringa ##, ###-###. ISSN 0311-5518.

Uppermost Cambrian (Furongian) and Lower Ordovician (Tremadocian) deposits of eastern Alborz in northern Iran contain several successive low- to moderate-diversity conodont associations including 13 genera and 19 species of euconodonts, paraconodonts and protoconodonts, which define six biozones: 1, the Proconodontus muelleri; 2, Eoconodontus notchpeakensis; 3, Cordylodus andresi; 4, Cordylodus proavus; 5, Paltodus deltifer; and 6, Paroistodus proteus zones. With the exception of Cordylodus andresi, which is otherwise known from Baltoscandia and from the Oaxaquia terrane (Mexico), all index-taxa are geographically widespread, allowing long-range correlation within the Cold Domain or the North Atlantic Province, and in particular with Baltica. Invasion of euconodonts in the Alborz region, defined by the first occurrence of Proconodontus muelleri, coincides closely with a steady rise in sea level and termination of carbonate sedimentation, whereas the transition from the Proconodontus muelleri to Eoconodontus notchpeakensis zones occurs during a highstand interval unlike in Laurentian sequences. The interval corresponding to the Cordylodus andresi and Cordylodus proavus zones, and the transition from the Paltodus deltifer to Paroistodus proteus zones coincided with unstable sea levels and the formation of shoal complexes. The lower boundary of the Floian Stage can be provisionally placed slightly below the first documented occurrence of Acodus sp. cf. A. kechikaensis, somewhat below the second unit of andesitic lava flows in the Simeh-Kuh section.

Hadi Jahangir [jahangir.hadi@gmail.com] and Alireza Ashuri [ashouri2001@yahoo.com] Department of Geology, Faculty of Sciences, Ferdowsi University, Azadi Square, Mashhad 91775-1436, Iran; Mansoureh Ghobadi Pour* [mghobadipour@yahoo.co.uk; m.ghobadipour@gu.ac.ir] and Arash Amini [a.amini@gu.ac.ir], Department of Geology, Faculty of Sciences, Golestan University, Gorgan 49138-15739, Iran. *Also affiliated with Department of Geology, National Museum of Wales, Cathays Park, Cardiff CF10 3NP, UK.     

On the integration of Ordovician conodont and graptolite biostratigraphy: new examples from Gansu and Inner Mongolia in China

Wang, Z.H., Bergström, S.M., Zhen, Y.Y., Chen, X. & Zhang, Y.D., 2013. On the integration of Ordovician conodont and graptolite biostratigraphy: New examples from Gansu and Inner Mongolia in China. Alcheringa 37, 510–528. ISSN 0311-5518.

Few Ordovician successions in the world contain both biostratigraphically highly diagnostic conodonts and graptolites permitting an integration between standard biozones based on these fossil groups. The Sandbian Guanzhuang section in the vicinity of Pingliang in the Gansu Province has an outstanding graptolite record through most of the Nemagraptus gracilis and Climacograptus bicornis graptolite biozones. Calcareous interbeds in the succession yield biostratigraphically important conodonts, including some species used for biozonations in Baltoscandia and the North American Midcontinent. Likewise, the middle–upper Darriwilian Dashimen section in the Wuhai region of Inner Mongolia hosts both diverse graptolites of the Pterograptus elegans, Didymograptus murchisoni and lowermost Nemagraptus gracilis biozones, and conodonts of Midcontinent and Baltoscandic types. The distribution patterns of these index fossil groups provide an unusual opportunity to closely correlate conodont and graptolite biozones in the middle to upper Darriwilian to Sandbian interval. For instance, the base of the C. bicornis Biozone is approximately coeval with the base of the Baltoscandic B. gerdae Subbiozone and a level near the middle of the North American P. aculeata Biozone.

Zhi-hao Wang [zhwang@nigpas.ac.cn] Xu Chen [xu1936@gmail.com], and Yuan-dong Zhang [ydzhang@nigpas.ac.cn], Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China; Stig M. Bergström [stig@geology.ohio-state.edu], School of Earth Sciences, Division of Earth History, The Ohio State University, Columbus, OH 43210, USA; Yong Yi Zhen [yongyi.zhen@austmus.gov.au], Australian Museum, 6 College Street, Sydney NSW 2010, Australia.     

Revision of the type species of Phoidagnostus Whitehouse, 1936 (Middle Cambrian,Agnostida)

The type species of Phoidagnostus, P. limbatus Whitehouse, 1936, is redescribed on the basis of further excavation of the holotype which has revealed an associated pygidium. This also demonstrates that the species Hypagnostus varicosus Öpik, 1961 is a junior subjective synonym of P. limbatus. Phoidagnostus is closely related to Toragnostus and Cotalagnostus.     

Conodont fauna and biostratigraphy of the Honghuayuan Formation (Early Ordovician) of Guizhou,South China

Serratognathus diversus An, Cornuodus longibasis (Lindström), Drepanodus arcuatus Pander, and eleven other less common conodonts, including Cornuodus? sp., Oistodus lanceolatus, Protopanderodus gradatus, Protoprioniodus simplicissimus, Juanognathus variabilis, Nasusgnathus dolonus, Paltodus? sp., Scolopodus houlianzhaiensis, Semiacontiodus apterus, Semiacontiodus sp. cf. S. cornuformis and Serratognathoides? sp., are described and illustrated from the Honghuayuan Formation in Guizhou, South China, concluding revision of the conodont fauna from this unit, which comprises 24 species in total. The most distinctive species in the fauna, S. diversus, consists of a trimembrate apparatus, including symmetrical Sa, asymmetrical Sb and strongly asymmetrical Sc elements. This species concept is supported by the absence of any other element types in a large collection represented by nearly 500 specimens of this species. The fauna indicates a late Tremadocian to mid-Floian age (Early Ordovician) for the Honghuayuan Formation, which was widely distributed on the Yangtze Platform in shallow water environments. Previously published biostratigraphic zonations for the Honghuayuan Formation are reviewed, and revised on the basis of our knowledge of the entire conodont fauna, supporting the establishment of three biozones, Triangulodus bifidus, Serratognathus diversus, and Prioniodus honghuayanensis biozones in ascending order. Species of Serratognathus enable correlation between Ordovician successions of South China, North China (North China Platform and Ordos Basin), Tarim Basin, and further afield into Malaysia and northwestern Australia.     

Ordovician (Bendigonian,Darriwilian to Gisbornian) faunas from the northern Molong Volcanic Belt of central New South Wales

Diverse shallow water assemblages dominated by brachiopods, molluscs, sponges and stromatoporoids, and a tabulate coral, in the Wahringa Limestone Member (Darriwilian-Gisbornian), and Yuranigh Limestone Member (Gisbornian, or early Late Ordovician) of the Fairbridge Volcanics, are documented from the northern Molong Volcanic Belt in central N.S.W. New species described include Billingsaria spissa, Shlyginia printhiensis and Sowerbyites? wahringaensis. Elements of the Wahringa Limestone Member assemblage such as Labechia banksi, Labechiella regularis, and Maclurites cf. M. florentinensis are biogeographically significant in displaying strong similarities with contemporaneous Tasmanian faunas. The brachiopods Ishimia and Shlyginia from the Yuranigh Limestone Member are recognised for the first time outside Kazakhstan and Sibumasu. The presence of the brachiopod Anoptambonites in allochthonous limestone breccia within the lower Fairbridge Volcanics provides evidence of a regionally significant hiatus of 10–15 Ma duration separating this unit from the underlying Hensleigh Siltstone, of Early Ordovician (Bendigonian) age. The sponge Archaeoscyphia?, from allochthonous limestones in the latter formation, is the oldest macrofossil yet described from the Lachlan Fold Belt in central N.S.W.     

Early Triassic mastodonsaurids (Temnospondyli,Stereospondyli) from Western Australia,with remarks on mastodonsauroid palaeobiogeography

A newly discovered partial skull of a temnospondyl from the Early Triassic Blina Shale of the Erskine Range, Western Australia, is referred to the mastodonsaurid species Watsonisuchus aliciae. A partial skull described as ‘Parotosuchus’ sp. by Warren (1980) is also referred to W. aliciae. Both taxonomic assignments should be treated with caution because of the relatively poor state of preservation of the specimens. W. aliciae is the fourth temnospondyl species to be described from the Blina Shale. The worldwide distribution of mastodonsauroids at the base of the Triassic suggests a rapid phase of radiation and dispersal following the Permo-Triassic extinction event.     

Issues and Opportunities in Planning and Managing Nature‐based Tourism in the Central Coast Region of Western Australia

Research reported here identified planning and management issues relating to integrated development of nature‐based tourism in the Central Coast Region of Western Australia. Stakeholder views were gauged through a workshop involving 45 people and a series of interviews. The workshop was also designed to stimulate interest in the establishment of a regionally, integrated tourism group to address any issues identified. Participants included members of the tourism industry, the community, and representatives of government and non‐government organisations. Seven individuals participated in interviews, including the chief executive officers of the local authorities and regional development commissions. The results indicate that the regional tourism industry is fragmented and uncoordinated, which is hindering regional development. Implementation of regional tourism planning is virtually non‐existent in the Central Coast, due to the lack of a regional tourism policy. Management of tourism resources is restricted by limited coordination between industry and government, and especially by inadequate resource provision to local authorities and land management agencies. An outcome of the workshop was the formation of a regionally integrated tourism group, the Turquoise Coast Sustainable Development Steering Committee, to implement recommendations arising from the workshop. However, the group has met with limited successes to date, owing to a range of political and sectoral issues beyond the scope of tourism planning. The research highlights difficulties in implementing collaborative tourism planning initiatives at the regional scale.     

Palaeobiogeography of the Ordovician trilobite Prosopiscus,with a new species from western New South Wales

Prosopiscus is particularly important in Ordovician palaeobiogeography because of its wide geographic distribution in Gondwana and peri-Gondwanan regions. It appears to have been confined to low palaeolatitudes, representing a characteristic member of the warm water eastern Gondwanan shelf faunas. Trends in the distribution of the Ordovician genus can be observed due to its long stratigraphic range. Prosopiscus was restricted to, and may have originated in, Australia during the late Early Ordovician (Bendigonian-Chewtonian). By the Middle Ordovician (Darriwilian), Prosopiscus had dispersed to other parts of Gondwana and peri-Gondwana, including the North and South China blocks, Tarim, central Himalayas, and the Argentine Precordillera (South America). Possible explanations for the distribution of Prosopiscus are that: (1) there were no oceanic barriers preventing dispersal of trilobites between different regions of Gondwana, thus permitting uninhibited migration over vast distances; (2) Prosopiscus was not restricted to a specific biofacies; (3) a major eustatic transgression during the early Darriwilian may have facilitated the dispersal of Prosopiscus in allowing further development and expansion of marine environments; and (4) a prolonged planktonic larval stage may have permitted wide dispersal.

Prosopiscus lauriei sp. nov. is described from the late Early Ordovician (Bendigonian-Chewtonian) Tabita Formation at Mount Arrowsmith, northwestern New South Wales, Australia. The new species is closely related to P. praecox, from the Nora Formation, Georgina Basin, central Australia, and to P. magicus from northwest China.     

Occurrence of the ammonite Goodhallites goodhalli (J. Sowerby) in the Eromanga Basin,Queensland: an index species for the late Albian (Cretaceous)

Mortoniceratid ammonites of the Eromanga Basin of Queensland, although uncommon, are reviewed and reassessed utilising all known collections. Representatives of this group are restricted to the Allaru Formation and almost all specimens are Goodhallites goodhalli, a well-known species from the English Gault. The Allaru Formation overlies the Toolebuc Formation, widely considered to be an essentially isochronous unit because of its unusual sedimentary and geochemical character. Using G. goodhalli, the middle and upper Allaru Formation can be directly correlated with the early late Albian orbignyi and auritus Subzones of the Mortoniceras inflatum Zone as recognized in the reference ammonite zonation embedded in the standard Cretaceous time scale. Overlapping ranges of G. goodhalli and Labeceras and Myloceras allow these common Austral heteromorph genera to be also confidently assigned a late Albian age in Australia, matching their biostratigraphic occurrence in South Africa.