Ancient Environments

Hendra, Australia

Ancient Environments

Hendra, Australia
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McLoughlin S.,Swedish Museum of Natural History | Pott C.,Swedish Museum of Natural History | Sobbe I.H.,Ancient Environments | Sobbe I.H.,University of Queensland
Palaeobiodiversity and Palaeoenvironments | Year: 2017

Several dispersed reproductive organs of bennettitopsid gymnosperms are described and illustrated from Triassic to Cretaceous strata of Australia: Williamsonia eskensis sp. nov. (Middle Triassic), Williamsonia ipsvicensis sp. nov. (Upper Triassic), Williamsonia durikaiensis sp. nov. (Lower Jurassic), Williamsonia sp. (Lower Jurassic), Williamsonia rugosa sp. nov. (Middle Jurassic), Williamsonia gracilis sp. nov. (Lower Cretaceous), Cycadolepis ferrugineus sp. nov. (Lower Jurassic), Cycadolepis sp. (Lower Cretaceous), and Fredlindia moretonensis Shirley 1898 comb. nov. (Upper Triassic). Among these, W. eskensis appears to represent the oldest bennettitalean reproductive structure yet identified. Although global floras expressed less provincialism during the Mesozoic and many genera are cosmopolitan, Australian bennettopsid species appear to have been endemic based on the morphological characters of the reproductive structures. Bennettopsids have a stratigraphic range of around 210 million years in Australia and are widely and abundantly represented by leaf fossils, but only around 20 specimens of reproductive structures, of which half are attributed to Fredlindia, have been recovered from that continent’s geological archive. The extremely low representation of reproductive organs vis-à-vis foliage is interpreted to reflect a combination of physical disintegration of the seed-bearing units while attached to the host axis and, potentially, extensive vegetative reproduction in bennettopsids growing at high southern latitudes during the Mesozoic. © 2017 The Author(s)

News Article | December 7, 2015

Researchers stand near the entrance of Ashalim Cave, where they found the lead artifact. More A lead and wood artifact discovered in a roughly 6,000-year-old grave in a desert cave is the oldest evidence of smelted lead on record in the Levant, a new study finds. The artifact, which looks like something between an ancient wand and a tiny sword, suggests that people in Israel's northern Negev desert learned how to smelt lead during the Late Chalcolithic, a period known for copper work but not lead work, said Naama Yahalom-Mack, the study's lead researcher and a postdoctoral student of archaeology with a specialty in metallurgy at the Institute of Earth Sciences and the Institute of Archaeology at The Hebrew University of Jerusalem. Moreover, an analysis of the lead suggests that it came from Anatolia (in modern-day Turkey), which is part of the Levant, or the area encompassing the eastern Mediterranean. The artifact was likely a valuable tool, given that it shows signs of wear and was placed in a grave alongside the remains of an individual in the cave, she said. [See Photos of Another Ancient Burial in the Southern Levant] "This is an incredible find," Yahalom-Mack told Live Science. "It's a uniquely preserved object from the late fifth millennium, which includes metal that was brought all the way from Anatolia. It probably had very high significance for the people who were buried with it." Researchers discovered the artifact in Ashalim Cave, a sprawling underground cavern that's been on archaeologists' radar since the 1970s. In 2012, the Israel Cave Research Center remapped the cave, and called in a team of archaeologists when they discovered artifacts. Archaeologists Mika Ullman and Uri Davidovich led the archaeological survey and studied the mazelike rooms, including one used for a burial chamber. The chamber was so small and low that they had to get down on their stomachs and wiggle forward to see the secluded space, Yahalom-Mack said. It was there that they found the lead artifact. "It was just lying there," Yahalom-Mack said. "All they needed to do was pick it up from the surface of the cave." The artifact is small — a stick of wood attached to a sculpted lead piece. The wood measures 8.8 inches (22.4 centimeters) long, and is made of tamarisk (a group of plants common in the Negev desert, from the genus Tamarix). The lead piece is 1.4 inches (3.7 cm) long and weighs about 5.5 ounces (155 grams), according to the study. Radiocarbon dating suggests the wood was created between 4300 B.C. and 4000 B.C., "which is extremely early," Yahalom-Mack said. "For a wooden artifact to be preserved [that long] is incredible." Lead, a bluish-white and malleable metal, is typically found with other elements — such as zinc, silver and copper — in nature. Lead is rarely found by itself, meaning that metal workers have to smelt it — or heat and extract it from rocks known as ore that contain metals and other minerals. In fact, smelted lead is unheard of during the Late Chalcolithic, Yahalom-Mack said. During that time, people had figured out how to smelt copper and copper alloys — which is unusual, given that copper is more difficult to smelt than lead because lead can be smelted at lower temperatures. Lead doesn't tend to occur naturally in the Negev desert, so after discovering the artifact, the researchers studied its isotopes (variations of an element) to determine its origin. An analysis showed that the artifact "was made of almost pure metallic lead, likely smelted from lead ores originating in the Taurus [mountain] range in Anatolia," the researchers wrote in the study. [In Photos: Amazing Ruins of the Ancient World] Perhaps the finished artifact was brought from Anatolia, or maybe the raw materials made their way to the southern Levant, where the object was assembled, the researchers said. "In this respect, it fits very well with what we know about the Chalcolithic culture, which was a highly developed culture with amazing abilities in art and craft," Yahalom-Mack said. People from the Chalcolithic period also carved ivory and used a sophisticated method known as "lost-wax casting" to fashion metal objects, she said. How the Late Chalcolithic people used the artifact, however, is anyone's guess. It could be a mace-head used mostly for ceremonial purposes, as mace-heads (clublike objects) were found at another Late Chalcolithic archaeology site known as Nahal Mishmar, or the Cave of the Treasure, in the southern Levant. But unlike the Nahal Mishmar mace-heads, the newfound artifact is likely not made of cast metal, and it's also smaller, so it may have served another purpose, Yahalom-Mack said. Another idea is that the artifact is a spindle, with the wooden shaft serving as the spindle rod and the lead object serving as a weight known as a whorl. There are abrasions on the lead that could have been made by spinning, and Dafna Langgut, a co-researcher of the study and the director of the Laboratory of Archaeobotany and Ancient Environments at Tel Aviv University, is investigating this idea. If the object were a spindle, its whorl would have been slightly heavier than most known whorls (which are typically made of stone), meaning the artifact would have produced only coarse yarn, Yahalom-Mack noted. Because of this discrepancy, the researchers speculate that the artifact was used for some unknown purpose before being repurposed as a spindle whorl, they said in the study. "Its eventual deposition in the deepest section of Ashalim Cave, in relation to the burial of selected individuals, serves as evidence of the symbolic significance it possessed until the final phase of its biography," the researchers wrote. There are a few examples of lead work during the Late Chalcolithic, but none has been studied as thoroughly as the new artifact. For instance, archaeologists have found two lead objects dating to before the fourth millennium B.C. in northern Mesopotamia and eastern Anatolia. But because these objects haven't been examined, it's unknown whether they were smelted or crafted from native lead, Yahalom-Mack said. However, if these two objects were smelted, it would suggest that ancient people in the Middle East had learned how to smelt lead but that the groups likely learned this skill independently of each other, at around the same time during the Late Chalcolithic, Yahalom-Mack said. The findings were published online Wednesday (Dec. 2) in the journal PLOS ONE. Copyright 2015 LiveScience, a Purch company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Burrow C.J.,Ancient Environments | Rudkin D.,Royal Ontario Museum
PLoS ONE | Year: 2014

Background: The relationships between early jawed vertebrates have been much debated, with cladistic analyses yielding little consensus on the position (or positions) of acanthodians with respect to other groups. Whereas one recent analysis showed various acanthodians (classically known as 'spiny sharks') as stem osteichthyans (bony fishes) and others as stem chondrichthyans, another shows the acanthodians as a paraphyletic group of stem chondrichthyans, and the latest analysis shows acanthodians as the monophyletic sister group of the Chondrichthyes. Methodology/Principal Findings: A small specimen of the ischnacanthiform acanthodian Nerepisacanthus denisoni is the first vertebrate fossil collected from the Late Silurian Bertie Formation Konservat- Lagerstätte of southern Ontario, Canada, a deposit well-known for its spectacular eurypterid fossils. The fish is the only near complete acanthodian from pre-Devonian strata worldwide, and confirms that Nerepisacanthus has dentigerous jaw bones, body scales with superposed crown growth zones formed of ondontocytic mesodentine, and a patch of chondrichthyan-like scales posterior to the jaw joint. Conclusions/Significance: The combination of features found in Nerepisacanthus supports the hypothesis that acanthodians could be a group, or even a clade, on the chondrichthyan stem. Cladistic analyses of early jawed vertebrates incorporating Nerepisacanthus, and updated data on other acanthodians based on publications in press, should help clarify their relationships. © 2014 Burrow et al.

White M.A.,University of Newcastle | Falkingham P.L.,Royal Veterinary College | Falkingham P.L.,Brown University | Cook A.G.,Ancient environments | And 2 more authors.
Alcheringa | Year: 2013

Various comparisons of left metacarpal I of the Australovenator wintonensis holotype have been made with Rapator ornitholestoides. These specimens were identified as being morphologically more similar than either was to that of the neovenatorid Megaraptor namunhuaiquii. Owing to the poor preservation of A. wintonensis and R. ornitholestoides, distinct morphological separation between the two appeared minimal. The recent discovery of a near perfectly preserved right metacarpal I of A. wintonensis enables a direct and accurate comparison with R. ornitholestoides. Distinct morphological differences exist between the metacarpals of the two species. A re-evaluation of the age of the A. wintonensis holotype site (AODL 85 'Matilda Site') with zircon dating reveals a maximum age of 95 Ma, 10 Ma younger than the Griman Creek Formation at Lightning Ridge, from which R. ornitholestoides was recovered. This age difference detracts from the probability that the specimens belong to the same genus. © 2013 Association of Australasian Palaeontologists.

Newman M.J.,Vine Lodge | Burrow C.J.,Ancient Environments | den-Blaauwen J.L.,University of Amsterdam | Davidson R.G.,35 Millside Road
Geodiversitas | Year: 2014

The five species of genus Euthacanthus Powrie, 1864 are reduced to two species on morphological and stratigraphical evidence. Euthacanthus macnicoli Powrie, 1864 and Euthacanthus grandis Powrie, 1870 are here synonymised in the type species E. macnicoli Powrie, 1864. In a previous article, Euthacanthus gracilis Powrie, 1870 and Euthacanthus elegans Powrie, 1870 were combined in the species E. gracilis, and the fifth species, Euthacanthus curtus Powrie, 1870, was reassigned to Uraniacanthus curtus (Powrie, 1870). In this work, we give an in-depth study of the full range of morphological and histological structure of scales over the body of E. macnicoli, as well as of fin spine structure. Our study reveals new features of E. macnicoli, including a large ornamented dorsal sclerotic bone, ornament on the branchiostegal plates, a separate series of gular rays, calcified cartilage forming the jaws, and a postbranchial protruding spinose plate rather than the flat prepectoral plate previously described. © Publications Scientifiques du Muséum national d’Histoire naturelle, Paris.

Burrow C.J.,Ancient Environments | Newman M.J.,Vine Lodge | Davidson R.G.,35 Millside Road | den Blaauwen J.L.,University of Amsterdam
Alcheringa | Year: 2013

Parexus Agassiz was one of the first Early Devonian 'spiny sharks' to be described. The genus is readily recognized by the large size and ornament of its anterior dorsal fin spine. Although two species were erected, reappraisal of all known specimens indicate they should be synonymized in the type species Parexus recurvus. Farnellia tuberculata Traquair, originally described as a vertebral column, is actually tooth rows of jaw dentition, and is also now considered to be a junior synonym of P. recurvus. Parexus has a perichondrally ossified scapulocoracoid of typical acanthodian shape, and diagnostic features of the family Climatiidae, but has distinctive scales comprising appositional growth zones that closely resemble those of the putative stem chondrichthyan Seretolepis elegans Karatajute-Talimaa. © 2013 Copyright Taylor and Francis Limited.

Articulated specimens of jawed fishes, and assemblages of disarticulated elements that can be assigned to a single biological species, are extremely rare from pre-Devonian deposits. The acanthodian species Ischnacanthus? scheii Spjeldnaes is based on a monospecific assemblage, comprising fin spines, dentigerous jaw bone fragments and scales, from the ?Siluro-Devonian boundary beds of the Devon Island Formation in central west Ellesmere Island, Canadian Arctic Archipelago, Nunavut. A new examination of the type material, in particular by scanning electron microscopy and thin sectioning of scales, shows that the species is a porosiform poracanthodid that is now assigned to Radioporacanthodes scheii comb. nov. Scales of the same species are also recognized from the upper Pridoli of Cornwallis Island and the ?Pridoli or Lochkovian of north Greenland.

Newman M.J.,Vine Lodge | Davidson R.G.,35 Millside Road | Den Blaauwen J.L.,University of Amsterdam | Burrow C.J.,Ancient Environments
Geodiversitas | Year: 2012

The acanthodian originally described as Euthacanthus curtus Powrie, 1870 from the Early Devonian (Lochkovian) of Scotland was tentatively reassigned to Diplacanthus Agassiz, 1844 later in the nineteenth century, although doubt was cast on this revision. In 1976 Paton suggested that specimens comparable with the single type could belong to Uraniacanthus Miles, 1973, based on similarities with the type species U. spinosus Miles, 1973 from the Lochkovian of England. Hanke et al. (2001) noted that the Canadian Lochkovian species Gladiobranchus probaton Bernacsek & Dineley, 1977 was also very similar to U. spinosus. Our investigations indicate that all three species belong to the genus Uraniacanthus (which has priority over Gladiobranchus Bernacsek & Dineley, 1977) in the family Gladiobranchidae Bernacsek & Dineley, 1977, order Diplacanthiformes Berg, 1940 (revised). This identification supports a biogeographical connection between the Canadian, Scottish and English Early Devonian based on the common presence of the genus Uraniacanthus, as well as other acanthodian genera, including Ischnacanthus Powrie, 1864. Uraniacanthus could also be represented by isolated scales in coeval deposits in the Baltic. © Publications Scientifiques du Muséum national d'Histoire naturelle, Paris.

Turner S.,Ancient Environments
Geoheritage | Year: 2013

Geology and landscape profoundly influence society, civilization and cultural diversity on our planet. The subtle relationships between peoples have changed irrevocably since our species began its journey in the Ice Age. The last 10,000 years have been a boom time: we planted crops, domesticated animals and built cities; population burgeoned; and in most places, the link to the land was lost. Important geological places (geosites) help us to rekindle and remember our place. Our geoheritage, now with the added designation of 'Geoparks', needs to reflect this intimate relationship: by helping people refind their roots and learning from early and indigenous people through their experiences to answer modern challenges, such as surviving climate change. The Geopark concept has brought economic revitalization to many rural regions, assisting local communities and indigenous populations, and added a new tool for geoconservation. In particular, women are being empowered to pursue new lines of work and to get involved in the Geopark process. Examples from Australian, Chinese, European and Iranian Geoparks show how the Global Geopark Network is supporting UNESCO ideals for women in the twenty-first century. This trend is important because women are traditionally the primary educators of children and they bring different perspectives to understanding geoheritage and to the Geopark process. © 2013 The European Association for Conservation of the Geological Heritage.

Burrow C.J.,Ancient Environments | Turner S.,Ancient Environments | Turner S.,Curtin University Australia
Historical Biology | Year: 2013

Gladbachus adentatus is a putative chondrichthyan, known only from the holotype specimen, which comprises an articulated endoskeleton complete from head to pelvic region with the squamation also preserved. The scales superficially resemble those of placoderms more than sharks, in having a similar gross morphology, lamellar cellular bone forming the base and upright dentinous tubercles comprising the crown. The odontocytic mesodentine in the tubercles is comparable to that in the Osteostraci and in some acanthodian taxa, known only from isolated scales, and is probably the plesiomorphic form of dentine for Gnathostomata. © 2013 Copyright Taylor and Francis Group, LLC.

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