Ben Creisler
A special issue not yet mentioned of open access journal Annales Societatis Geologorum Poloniae 88(2) with papers from the 2nd International Conference of Continental Ichnology (2017).
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Papers that may be of particular interest to the DML:
Sean J. FISCHER & Stephen T. HASIOTIS (2018)
Ichnofossil assemblages and palaeosols of the Upper Triassic Chinle Formation, south-eastern Utah (USA): Implications for depositional controls and palaeoclimate.Â
Annales Societatis Geologorum Poloniae 88(2): 127â162
The Upper Triassic Chinle Formation in the Stevens Canyon area in south-eastern Utah represents fluvial, palustrine, and lacustrine strata deposited in a continental back-arc basin on the western edge of Pangea. Previous investigations interpreted a megamonsoonal climate with increasing aridity for the Colorado Plateau towards the end of the Triassic. In this study, we systematically integrate ichnological and pedological features of the Chinle Formation into ichnopedofacies to interpret palaeoenvironmental and palaeoclimatic variations in the north-eastern part of the Chinle Basin. Seventeen ichnofossil morphotypes and six palaeosol orders are combined into twelve ichnopedofacies, whose development was controlled by autocyclic and allocyclic processes and hydrology. Ichnopedofacies are used to estimate palaeoprecipitation in conjunction with appropriate modern analogue latitudinal and geographic settings. In the north-east Chinle Basin, annual precipitation was ~1100â1300 mm in the Petrified Forest Member. Precipitation levels were >1300 mm/yr at the base of the lower Owl Rock Member, decreased to ~700â1100 mm/yr, and then to ~400â700 mm/yr. Two drying upward cycles from ~1100 mm/yr to ~700 mm/yr occurred in the middle and upper part of the Owl Rock Member. In the overlying Church Rock Member, precipitation decreased from ~400 mm/yr at the base of the unit to ~25â325 mm/yr at the end of Chinle Formation deposition. Ichnopedofacies indicate monsoonal conditions persisted until the end of the Triassic with decreasing precipitation that resulted from the northward migration of Pangea. Ichnopedofacies in the northeast Chinle Basin indicate both long-term drying of climate and short-term, wet-dry fluctuations.
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Previously posted in advance publication form on the DML:
Akhil RAMPERSADH, Emese M. BORDY, Lara SCISCIO & Miengah ABRAHAMS (2018)
Dinosaur behaviour in an Early Jurassic palaeoecosystem -- uppermost Elliot Formation, Ha Nohana, Lesotho.
Annales Societatis Geologorum Poloniae 88(2): 163â179
The Ha Nohana palaeosurface in southern Lesotho preserves tridactyl and tetradactyl tracks and trackways attributable to Early Jurassic bipedal, theropod-like dinosaurs. Complementary sedimentological and ichnological observations along the palaeosurface and in the strata below and above it allow detailed interpretations of climatically driven changes in this southern Gondwana palaeoecosystem. Sedimentological evidence suggests trackmaking under a semi-arid climate with heavy storms and episodic flash flooding that induced ephemeral, unconfined sheetwashes. The palaeosurface is overlain by rhythmically bedded, organic-matter rich mudstones that formed in a deep, stratified lake indicative of a longer and wetter period in the history of the site. The unique morphological details of the Ha Nohana tracks help refine the properties of the substrate during track making, the ichnotaxonomic affinities of the footprints and the interpretation of the foot movement relative to the substrate. Two footprint morphotypes, ~300 m apart, are defined on the palaeosurface. Tracks of morphotype I are tridactyl, shallow, contain digital pad impressions and were impressed on a firm, sand rippled substrate that underwent desiccation. Conversely, tracks of morphotype II are tetradactyl, deep, and have an elongated posterior region. These tracks are preserved on the surface of a massive sandstone and are associated with soft sediment collapse structures related to the animalâs foot sinking into the water-saturated, malleable sediment layer. Morphotype II tracks show that as the animal waded across the substrate, the liquefied sediment lost its cohesive strength and could only partially support the weight of the animal. In so doing, the animalâs foot sunk deep enough into the sediment such that the impression of the metatarsal and digit I (hallux) are now visible. Thus, the palaeosurface was walked on by small-to-medium sized theropods that traversed over ripple marks in firmer moist sand, as well as a larger theropod that tottered through water-logged sand.
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Derek C. W. RAISANEN & Stephen T. HASIOTIS (2018)
New ichnotaxa of vertebrate burrows from the Salt Wash Member, Upper Jurassic Morrison Formation, south-eastern Utah (USA).Â
Annales Societatis Geologorum Poloniae 88(2): 181â202
Large-diameter burrows in pedogenically modified floodplain deposits in the Salt Wash Member, Upper Jurassic Morrison Formation, southeast Utah, U.S.A., are interpreted to have been constructed by mammals. They are distinguished as Daimonelix martini isp. nov., which exhibits a helical shaft down to a horizontal tunnel with a mean depth of 71.4 cm from the inferred palaeosurface. The mean path length of the shaft is 99.4 cm; mean dip of the whorls is 39Â. The mean tunnel length is 42.3 cm. Shafts and tunnels are oval or elliptical in cross section with the horizontal diameter slightly larger than the vertical (ratio of ~1.26:1); the shaft averages 9.2 cm wide and 7.3 cm tall; the tunnel averages 10.7 cm wide and 10.7 cm tall. The tracemaker was likely a fossorial mammal that used the burrow as a den to shelter when not foraging above ground; the burrows are domichnia. The other from the same member is Fractisemita henrii igen. nov. et isp. nov., a network of interconnected shafts and tunnels; shaft and tunnel segments are straight, curved, or helical. The segments are at angles of 0â89Â; mean length of a section is 30.7 cm. The cross sections of all elements are oval or elliptical; the mean width is 6.3 cm and the mean height is 4.9 cm (ratio of ~1.29:1). The burrows are interpreted as the work of a social mammal and represent multiple tracemaker behaviours: protection, denning, foraging, and possibly food storage. The burrows are polychresichnia. Surficial morphologic features preserved on the burrow walls of both types are interpreted as scratches made by the tracemaker claws and/or teeth. The burrows reveal the actions of small vertebrates not recorded by body fossils showing potential partitioning of the environment and availability of resources for small vertebrates.
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Sandra BARRIOS-DE PEDRO & Ãngela D. BUSCALIONI (2018)
Scrutinizing Barremian coprolite inclusions to record digestive strategies.Â
Annales Societatis Geologorum Poloniae 88(2): 203â221
The exceptional preservation of the Las Hoyas coprolites allows the taphonomic study of inclusions on twelve morphotypes and twenty-three specimens. Non-destructive techniques were applied to study the digestion features (pitting, corrosion lines, shape of the fractures at the ends) and the arrangement, number, and size of inclusions. An analysis based on non-metric, multidimensional scaling ordination identified the similarities among the inclusion features and morphotypes. The morphotypes are clustered on the basis of the way of ingestion and the digestive process. The authors recognize three digestive strategies for the Las Hoyas coprolites: (1) ingestion of prey with limited processing in the mouth, scarce to less effective acid secretions, and/or defecation in a short period of time; (2) ingestion of the prey with mastication prior to deglutition, and defecation over a longer period of time; (3) mastication and long retention time of food in the digestive system with more effective acid secretions. This study is a first step in the understanding of the feeding ecology of the Las Hoyas Barremian lentic ecosystem, based on coprolites.
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Christian A. MEYER, Daniel MARTY & Matteo BELVEDERE (2018)
Titanosaur trackways from the Late Cretaceous El Molino Formation of Bolivia (Cal Orckâo, Sucre).Â
Annales Societatis Geologorum Poloniae 88(2): 223âââ241Â
Dinosaur tracks in South America are well-known since the seminal work of Leonardi (1989, 1994), although reports from Argentina were known earlier (e.g., Alonso, 1980). The first account of dinosaur tracks from Bolivia is that of Branisa (1968), who briefly mentioned surfaces from the El Molino Formation of Toro Toro. In 1994, Leonardi figured four different Cretaceous localities with dinosaur tracks, i.e., Toro Toro, Parotani (not verified), Arampampa (not verified) and Camargo (not verified). The footprints of ankylosaurs, theropods and sauropods from the Toro Toro site were figured by Leonardi (1994), but a detailed description of the site is missing. Furthermore, the presence of dromaeosaurid footprints at Toro Toro was mentioned by ApesteguÃa et al. (2007, 2011). In 1994, Jose Hugo Heymann (geologist) and Klaus Schuett (at that time Director of Tourism in Sucre) discovered tracks in the Cal Orckâo Quarry and brought them to the attention of the first author. In 1998, the first field work was carried out (mapping, casting) and the tracks were subsequently studied during field seasons in 2002, 2003, 2006, 2009, 2015 and 2017, respectively. The first results and subsequent studies revealed 3,500 footprints of five different dinosaur morphotypes (Meyer et al., 1999a, b; Meyer et al., 2001; McCrea et al., 2001; Meyer et al., 2006; ApesteguÃa et al., 2007). During these visits, other sites also have been brought to the attention of the authors. In 1998, a site in the Maragua syncline was mapped close to the village of Humaca, in the Chaunaca Formation (Lockley et al., 2002a).Â
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