Content uploaded by Andrew Rozefelds
Author content
All content in this area was uploaded by Andrew Rozefelds on Apr 11, 2016
Content may be subject to copyright.
A preview of the PDF is not available
A Cenomanian flora from the Winton Formation, Eromanga Basin, Queensland, Australia
Abstract
A middle Cretaceous (Cenomanian) fossil flora from the Winton Formation of central Queensland consists of six taxa of ferns, four conifers, one ginkgophyte, one pentoxylalean, and eight angiosperm leaf types. It is the oldest impression flora to contain abundant angiosperm leaves to date described in detail from Australia, and provides the first, direct, macrofossil evidence of the transition from gymnosperm- to angiosperm-dominated floras in Australia during the Cretaceous. The angiosperm leaves are mostly hamamelid types of probable fagaceous or betulaceous affinity, but precise relationships are unclear. The Winton angiosperm assemblages show some similarity to Late Cretaceous floras of New Zealand. -Authors
... macrofossils [111]. Ferns are quite diverse and abundant, with osmundaceans (Phyllopteroides macclymontae [111,113], Cladophlebis sp. [113]), gleicheniaceans (Microphyllopteris sp. ...
... Ferns are quite diverse and abundant, with osmundaceans (Phyllopteroides macclymontae [111,113], Cladophlebis sp. [113]), gleicheniaceans (Microphyllopteris sp. cf. ...
... cf. M. gleichenoides [113]) and tempskyaceans (Tempskya judithae [114]) all present, alongside species of uncertain phylogenetic position (e.g. Sphenopteris sp. ...
The Upper Cretaceous Winton Formation of Queensland, Australia, has produced several partial sauropod skeletons, but cranial remains—including teeth—remain rare. Herein, we present the first description of sauropod teeth from this formation, based on specimens from three separate sites. An isolated tooth and a dentary fragment from the Diamantinasaurus matildae type locality are considered to be referable to that titanosaurian taxon. A single tooth from the D. matildae referred specimen site is similarly regarded as being part of that individual. Seventeen teeth from a new site that are morphologically uniform, and similar to the teeth from the two Diamantinasaurus sites, are assigned to Diamantinasauria. All sauropod teeth recovered from the Winton Formation to date are compressed-cone-chisel-shaped, have low slenderness index values (2.00–2.88), are lingually curved at their apices, mesiodistally convex on their lingual surfaces, and lack prominent carinae and denticles. They are markedly different from the chisel-like teeth of derived titanosaurs, more closely resembling the teeth of early branching members of the titanosauriform radiation. This provides further support for a ‘basal’ titanosaurian position for Diamantinasauria. Scanning electron microscope microwear analysis of the wear facets of several teeth reveals more scratches than pits, implying that diamantinasaurians were mid-height (1–10 m) feeders. With a view to assessing the spatio-temporal distribution of sauropod tooth morphotypes before and after deposition of the Winton Formation, we provide a comprehensive continent-by-continent review of the early titanosauriform global record (Early to early Late Cretaceous). This indicates that throughout the Early–early Late Cretaceous, sauropod faunas transitioned from being quite diverse at higher phylogenetic levels and encompassing a range of tooth morphologies at the start of the Berriasian, to faunas comprising solely titanosaurs with limited dental variability by the end-Turonian. Furthermore, this review highlights the different ways in which this transition unfolded on each continent, including the earliest records of titanosaurs with narrow-crowned teeth on each continent.
... The fossil flora of the 'upper' Winton Formation is co-dominated by conifers (Peters and Christophel, 1978;Dettmann et al., 2012) and angiosperms (McLoughlin et al., 1995;Dettmann et al., 2009). Conifers include the cupressacean Austrosequoia wintonensis (Peters and Christophel, 1978), the araucariaceans Araucaria cf. ...
... Conifers include the cupressacean Austrosequoia wintonensis (Peters and Christophel, 1978), the araucariaceans Araucaria cf. mesozoica (McLoughlin et al., 1995) and Emwadea microcarpa (Dettmann et al., 2012), and the podocarpacean Protophyllocladoxylon owensii (Fletcher et al., 2014a), whereas the angiosperms comprise Lovellea wintonensis (Dettmann et al., 2009) and nine magnoliophyte forms left in open nomenclature (McLoughlin et al., 1995(McLoughlin et al., , 2010. Ferns are also abundant and diverse in the Winton Formation (McLoughlin et al., 2010), with Phyllopteroides macclymontae (Osmundaceae; McLoughlin et al., 1995) and Tempskya judithae (Tempskyaceae; Clifford and Dettmann, 2005) among the most notable. ...
... Conifers include the cupressacean Austrosequoia wintonensis (Peters and Christophel, 1978), the araucariaceans Araucaria cf. mesozoica (McLoughlin et al., 1995) and Emwadea microcarpa (Dettmann et al., 2012), and the podocarpacean Protophyllocladoxylon owensii (Fletcher et al., 2014a), whereas the angiosperms comprise Lovellea wintonensis (Dettmann et al., 2009) and nine magnoliophyte forms left in open nomenclature (McLoughlin et al., 1995(McLoughlin et al., , 2010. Ferns are also abundant and diverse in the Winton Formation (McLoughlin et al., 2010), with Phyllopteroides macclymontae (Osmundaceae; McLoughlin et al., 1995) and Tempskya judithae (Tempskyaceae; Clifford and Dettmann, 2005) among the most notable. ...
The titanosaurian sauropod dinosaur Savannasaurus elliottorum is represented by a partial postcranial skeleton from the lower Upper Cretaceous (Cenomanian-lowermost Turonian) Winton Formation of Queensland, northeast Australia. Here, we present a detailed description of this specimen, as well as an emended diagnosis for this titanosaur. Savannasaurus elliottorum displays numerous character states that are generally regarded as plesiomorphic for Titanosauria, as well as several traits that are often regarded as apomorphic of that clade or a less inclusive subset thereof. Several features of Savannasaurus support a close relationship with the coeval Diamantinasaurus matildae, and this clade appears to occupy an early-branching position within Titanosauria. Relative to body size, the thoracic and abdominal breadth of Savannasaurus is greater than that seen in giant titanosaurs such as the contemporaneous South American lognkosaurians; however, this relative breadth is not quite as extreme as that of the small-bodied latest Cretaceous saltasaurines, or Opisthocoelicaudia skarzynskii. The possible advantages engendered by the barrel-shaped thorax, robust limbs, wide-gauge gait, and lack of hyposphene-hypantrum articulations are explored, and it is hypothesized that these traits were positively selected by the wet, temperate floodplain environment in which Savannasaurus lived. Greater stability and flexibility might have reduced the risk of bogging, and/or facilitated more expedient self-extraction from muddy waterholes. Similar environmental pressures acting upon other titanosaurian taxa or clades elsewhere might have led to the repeated independent development, or accentuation, of the bauplan regarded as 'typical' for the clade Titanosauria. This would explain the many observed convergences between Savannasaurus and Diamantinasaurus, and Saltasauridae.. 2020. Osteology of the wide-hipped titanosaurian sauropod dinosaur Savannasaurus elliottorum from the Upper
... Two Australian species, Ginkgo australis (McCoy) Drinnan et Chambers (Douglas, 1965(Douglas, , 1994Drinnan and Chambers, 1986;Hill and Carpenter, 1999) and Ginkgo wintonensis McLoughlin, Drinnan et Rozefelds (McLoughlin et al., 1995), were described for Cretaceous and Paleogene deposits. Ginkgo australis is markedly larger size and more lobated (Douglas, 1965(Douglas, , 1994Hill and Carpenter, 1999;Villar de Seoane et al., 2015) than G. villardeseoanii, whereas G. wintonensis is very similar in morphology to G. villardeseoanii but it is generally smaller and has a distal sinuous margin (McLoughlin et al., 1995). ...
... Two Australian species, Ginkgo australis (McCoy) Drinnan et Chambers (Douglas, 1965(Douglas, , 1994Drinnan and Chambers, 1986;Hill and Carpenter, 1999) and Ginkgo wintonensis McLoughlin, Drinnan et Rozefelds (McLoughlin et al., 1995), were described for Cretaceous and Paleogene deposits. Ginkgo australis is markedly larger size and more lobated (Douglas, 1965(Douglas, , 1994Hill and Carpenter, 1999;Villar de Seoane et al., 2015) than G. villardeseoanii, whereas G. wintonensis is very similar in morphology to G. villardeseoanii but it is generally smaller and has a distal sinuous margin (McLoughlin et al., 1995). ...
Today, the ginkgophytes are represented by the single species Ginkgo biloba, naturally distributed in China and cultivated worldwide. However, the ginkgophyte lineage shows an extensive fossil record going back to the Paleozoic of both hemispheres. In South America, its record began in the upper Paleozoic and reached the middle Eocene, and it includes both vegetative and reproductive remains. The Cretaceous macrofossil record of this group in South America is restricted to Lower Cretaceous deposits, where it is relatively abundant, whereas there is a gap in its Upper Cretaceous to lower Paleogene record. We present the new species Ginkgoites villardeseoanii collected from Maastrichtian (uppermost Cretaceous) deposits of the Lefipán Formation (Patagonia, Argentina). The studied material consists of three specimens preserved as adpressions of isolated, flabellate, and petiolate (Ginkgo-like) leaves, with few epidermal characters preserved. One of the studied specimens shows evidence of insect damage consistent with hole feeding, constituting the first Cretaceous record of interaction between ginkgophytes and insects worldwide. We infer that this damage was produced when the leaf was still attached to the plant, as the specimen shows evidence of a physiological reaction of the plant in the form of a border of necrotic tissue around the wound. Ginkgoites leaves are common among different lineages within the Ginkgoales, having been associated to three families (Ginkgoaceae, Karkeniaceae, and Yimaiaceae). Therefore, G. villardeseoanii was assigned to an incertae sedis family.
... In Aculea, common dissected pinnae occur, similar to those in A. bifarius, but the segments are fewer, finer, and with a more symmetric and organized disposition. The broader paleogeographic fossil record of Aculea includes the previously mentioned forms of the Antarctic Peninsula (Cantrill, 1996), from the Cenomanian of the Eromanga Basin, in Australia ( McLoughlin et al., 1995), and the AlbianeCenomanian ones from the Kachaike Formation, Santa Cruz Province, Argentina. ...
The Campanian–Maastrichtian succession of Cerro Guido, Southern Chile, is known by its plant fossils, vertebrates bones, including those of dinosaurs, and marine faunas that can be critical in the better understanding of the processes involved in the Western Gondwana break-up in the southernmost paleolatitudes and their effects over life, paleoclimate and paleogeography. As part of the retroarc foreland deposits of the Magallanes or Austral Basin, the Upper Cretaceous rocks from Tres Pasos and Dorotea formations, source of the fossil ferns here discussed, are exposed at the southern side of the Cerro Guido hill. The leaves of pteridophytes were identified in a macroflora dominated by primitive angiosperms, conifers and Taeniopteris, where they represented a secondary component of the understory. The data obtained show terrestrial fern populations, dominated by Cladophlebis, the cosmopolitan ‘Mesozoic’ taxa, accompanied by forms related to Alsophila, Alamatus, and the extant genus Anogramma, similarly to other Southern Hemisphere areas, and especially with those from the lower Upper Cretaceous of New Zealand. Their scarcity in the Upper Cretaceous assemblages of the Tres Pasos and Dorotea formations supports the inferred near-coastal environmental context and contrasts with their abundance and diversity in the Aptian to Coniacian deposits of the northern Antarctic Peninsula. Additional evidence suggesting that these remains were remobilized corroborates with the idea that they are a part of the vegetation that grew around interdistributary rivers or bays.
... The first has craspedodromous-like venation with the main secondaries terminating in a major tooth at the leaf margin ( Supplementary Fig. 3 g). Similar types of leaves occur in the fossil assemblage from the Cretaceous Winton Formation of Australia 28 . The second taxon has larger leaves and more steeply/shallowly angled venation. ...
New Caledonia was, until recently, considered an old continental island harbouring a rich biota with outstanding Gondwanan relicts. However, deep marine sedimentation and tectonic evidence suggest complete submergence of the island during the latest Cretaceous to the Paleocene. Molecular phylogenies provide evidence for some deeply-diverging clades that may predate the Eocene and abundant post-Oligocene colonisation events. Extinction and colonization biases, as well as survival of some groups in refuges on neighbouring paleo-islands, may have obscured biogeographic trends over long time scales. Fossil data are therefore crucial for understanding the history of the New Caledonian biota, but occurrences are sparse and have received only limited attention. Here we describe five exceptional fossil assemblages that provide important new insights into New Caledonia’s terrestrial paleobiota from three key time intervals: prior to the submersion of the island, following re-emergence, and prior to Pleistocene climatic shifts. These will be of major importance for elucidating changes in New Caledonia’s floristic composition over time.
Skeletal remains of sauropod dinosaurs have been known from Australia for over 100 years. Unfortunately, the classification of the majority of these specimens to species level has historically been impeded by their incompleteness. This has begun to change in the last 15 years, primarily through the discovery and description of several partial skeletons from the Cenomanian-lower Turonian (lower Upper Cretaceous) Winton Formation in central Queensland, with four species erected to date: Australotitan cooperensis, Diamantinasaurus matildae, Savannasaurus elliottorum, and Wintonotitan wattsi. The first three of these appear to form a clade (Diamantinasauria) of early diverging titanosaurs (or close relatives of titanosaurs), whereas Wintonotitan wattsi is typically recovered as a distantly related non-titanosaurian somphospondylan. Through the use of 3D scanning, we digitised numerous specimens of Winton Formation sauropods, facilitating enhanced comparison between type and referred specimens, and heretofore undescribed specimens. We present new anatomical information on the holotype specimen of Diamantinasaurus matildae, and describe new remains pertaining to twelve sauropod individuals. Firsthand observations and digital analysis enabled previously proposed autapomorphic features of all four named Winton Formation sauropod species to be identified in the newly described specimens, with some specimens exhibiting putative autapomorphies of more than one species, prompting a reassessment of their taxonomic validity. Supported by a specimen-level phylogenetic analysis, we suggest that Australotitan cooperensis is probably a junior synonym of Diamantinasaurus matildae, but conservatively regard it herein as an indeterminate diamantinasaurian, meaning that the Winton Formation sauropod fauna now comprises three (rather than four) valid diamantinasaurian species: Diamantinasaurus matildae, Savannasaurus elliottorum, and Wintonotitan wattsi, with the latter robustly supported as a member of the clade for the first time. We refer some of the newly described specimens to these three species and provide revised diagnoses, with some previously proposed autapomorphies now regarded as diamantinasaurian synapomorphies. Our newly presented anatomical data and critical reappraisal of the Winton Formation sauropods facilitates a more comprehensive understanding of the mid-Cretaceous sauropod palaeobiota of central Queensland.
Macrofloristic or microfloristic zonation of MesozoicMesozoic successions, with or without independent marine–biostratigraphic age constraints, is extensively utilized in sedimentary basin analyses worldwide. However, precise macrofloral or palynological demarcation of the non-marine MesozoicMesozoic successions remains elusive in India. This uncertainty stems from several factors, including unfossiliferous deposits in critical stratigraphic intervals. However, marine fauna (ammonoids, foraminifers) have been well documented from the MesozoicMesozoic sequences of India and offer a unique correlation interface. We attempt to establish tie-points between these fauna and the macro and microflora from the East Coast sedimentary basins of India, which include the Cauvery and Palar basins of Tamilnadu, Krishna-Godavari and Pranhita-Godavari basinsPranhita-Godavari Basin of Andhra Pradesh and Mahanadi Basin of Orissa. They offer considerable potential to achieve an integrated correlation to establish a higher time resolution. The early CretaceousCretaceous lithounits in these basins provide a long-ranging Neocomian-Aptian age. This work aims to provide precise ages to these formations based on biostratigraphically diagnostic taxa, especially palynomorphsPalynomorph and macrofloraMacroflora. These ages are supported by correlation with reports of coeval marine fossils such as ammonoids, foraminifers and dinoflagellatesDinoflagellate wherever available. Thus, based on the marker taxa precise ages have been assigned to the lithounits of the east coast sedimentary basins. Palaeobiogegraphic studies indicate that latitudinal control on climate was a more important factor in delineating the paleofloristic realms. The development of the angiosperms took place around the Neocomian and their diversification around Aptian-Turonian. Marine routes were established along the margins of the southern continents.
A new fossil flora from central Queensland, of late Eocene or early Oligocene age, has yielded a diverse assemblage of flowering plants and ferns, including the first evidence of horsetails (Equisetum L.) from the Cenozoic of Australia. The fossils assigned to Equisetum are based on a stem fragment, 2–3mm in diameter, and spreading leaf sheath and diaphragm. The leaf sheath is interpreted to consist of ~24–30 leaves. The spatial arrangement of regularly arranged depressions in a section of the outer cortex is interpreted as evidence of the leaf vascular traces, and indicates a similar number of vascular traces. This specimen provides the youngest evidence of the genus from Australia and indicates that Equisetum survived for at least another 50 million years after it was thought to be extinct in Australia. Whereas molecular data for extant species of Equisetum collectively suggest a comparatively recent origin and radiation, the fossil record of the genus indicates a significantly longer and more complex history. Fossils, such as the new specimen from Makowata, Queensland, will, therefore, play a key role in understanding the history and past distribution of Equisetum in Australia. A key challenge is to assemble and characterise the morphological traits of these living and fossil plants to better understand the origins, history and radiation of this remarkable group of euphyllophytes.
The Winton Formation is increasingly recognised as an important source of information about the Cretaceous of Australia, and, more broadly, the palaeobiogeographic history of eastern Gondwana. With more precise dating and stratigraphic controls starting to provide temporal context to the geological and palaeontological understanding of this formation, it is timely to reassess the palaeoenvironment in which it was deposited. This new understanding helps to further differentiate the upper, most-studied portion of the formation (Cenomanian–Turonian) from the lower portions (Albian–Cenomanian), allowing a coherent picture of the ecosystem to emerge. Temperatures during the deposition of the Upper Cretaceous portion of the Winton Formation were warm, with high, seasonal rainfall, but not as extreme as the modern monsoon. The landscape was heterogeneous, a freshwater alluvial plain bestrode by low energy, meandering rivers, minor lakes and mires. Infrequent, scouring flood events were part of a multi-year cycle of drier and wetter years. The heavily vegetated flood plains supported abundant large herbivores. This was the final infilling of the great Eromanga Basin.
ResearchGate has not been able to resolve any references for this publication.