An overview of Upper Cretaceous dinosaur tracks and other trace fossils from the Barreales lake area, Neuquén Province, Patagonia, Argentina

Author(s):  
Jorge O. Calvo ◽  
Cynthia Rivera ◽  
Laura Avila
2014 ◽  
Vol 35 (4) ◽  
pp. 541-552 ◽  
Author(s):  
Tomasz Sulej ◽  
Andrzej Wolniewicz ◽  
Niels Bonde ◽  
Błażej Błażejowski ◽  
Grzegorz Niedźwiedzki ◽  
...  

Abstract The Fleming Fjord Formation (Jameson Land, East Greenland) documents a diverse assemblage of terrestrial vertebrates of Late Triassic age. Expeditions from the turn of the 21st century have discovered many important fossils that form the basis of our current knowledge of Late Triassic Greenlandic faunas. However, due to the scarcity and incompleteness of the fossils and their insufficient study, our understanding of the taxonomic diversity of the Fleming Fjord Formation is hindered. Here, we report the preliminary findings of a Polish-Danish expedition to the Fleming Fjord Formation that took place in 2014. Three areas were visited – the fairly well known MacKnight Bjerg and Wood Bjerg and the virtually unexplored Liasryggen. MacKnigth Bjerg and Liasryggen yielded fossils which promise to significantly broaden our knowledge of vertebrate evolution in the Late Triassic. Stem-mammal remains were discovered at Liasryggen. Other fossils found at both sites include remains of actinopterygians, sarcopterygians, temnospondyl amphibians and various archosaurs (including early dinosaurs). Numerous vertebrate trace fossils, including coprolites, pseudosuchian footprints, theropod and sauropodomorph dinosaur tracks, were also discovered. Newly discovered skeletal remains as well as abundant trace fossils indicate higher tetrapod diversity in the Late Triassic of Greenland than previously thought. Trace fossils also allow inferences of early theropod and sauropodomorph dinosaur behaviour.


Author(s):  
Max Wisshak

Dendritic and/or rosetted microborings in calcareous and osteic skeletal substrates have a diverse trace fossil record, spanning most of the Phanerozoic, whereas the ichnodiversity of comparable bioerosion traces produced in modern seas is rather limited. The most prominent occurrences are known from Devonian brachiopods and from Upper Cretaceous belemnite rostra. Ichnotaxonomically, they are comprised within one of the few ichnofamilies established to date, the Dendrinidae Bromley et al., 2007. As an outcome of the present revision of this ichnofamily, the plethora of 84 ichnospecies established within 25 ichnogenera since the erection of the type ichnogenus Dendrina Quenstedt, 1849 was considerably condensed to 22 ichnospecies included in 7 ichnogenera, based on a coherent morphological categorisation and ichnotaxobasis assessment. The suite of ichnogenera now subsumed within the Dendrinidae includes Dendrina Quenstedt, 1849; Clionolithes Clarke, 1908; Calcideletrix Mägdefrau, 1937; Dictyoporus Mägdefrau, 1937; Abeliella Mägdefrau, 1937; Nododendrina Vogel et al., 1987; and Pyrodendrina Tapanila, 2008. New combinations thereby concern Dendrina dendrina (Morris, 1851) comb. nov., Clionolithes pannosus (Solle, 1938) comb. nov., C. alcicornis (Vogel et al., 1987) comb. nov., C. convexus (Hofmann, 1996) comb. nov., Calcideletrix anomala (Mägdefrau, 1937) comb. nov., C. fastigata (Radtke, 1991) comb. nov., Dictyoporus balani (Tavernier et al., 1992) comb. nov., Nododendrina europaea (Fischer, 1875) comb. nov., N. incomposita (Mägdefrau, 1937) comb. nov. and N. paleodendrica (Elias, 1957) comb. nov. Investigation of new material and a reassessment of 63 dendrinid microborings previously addressed in informal nomenclature allowed the establishment of two complementing ichnogenera, Rhopalondendrina igen. nov. and Antodendrina igen. nov., and eight new ichnospecies, comprising Pyrodendrina arctica isp. nov., P. belua isp. nov., P. villosa isp. nov., Rhopalondendrina avis igen. et isp. nov., R. acanthina igen. et isp. nov., R. contra igen. et isp. nov., R. tigris igen. et isp. nov. and Antodendrina ligula igen. et isp. nov. In densely bioeroded calcareous substrates, different dendrinids and other bioerosion traces may be found in direct contact with each other, forming composite trace fossils, but some of these associations appear rather systematic in nature and could be the work of the same tracemaker under different behavioural modes, thus forming compound trace fossils. In these cases, however, the distinction between the two concepts remains largely equivocal. Dendrinid microborings are primarily found in living and dead calcareous skeletal substrates of bivalves, brachiopods, belemnites and corals, with complementing records from six other substrate types. Facing considerable sampling artefacts, evidence for true substrate specificity or symbiotic relationships is inconclusive as yet, whereas there is direct evidence for post-mortem infestation in several cases, such as the diverse dendrinid associations in Upper Cretaceous belemnite guards. Despite a wealth of available interpretations, the actual biological identity of the dendrinids’ tracemakers remains largely speculative. The most convincing evidence has been put forward in support of foraminiferans as the producers of Nododendrina, and excavating micro-sponges producing Clionolithes and some Calcideletrix. Since most of the dendrinids are found in aphotic (palaeo-)environments, these two principal types of organotrophic tracemakers are also potential candidates for the other ichnogenera. With regards to evolutionary patterns through geologic time, strong adaptive radiations are evident from the ichnodiversity of dendrinid ichnospecies in the Early to Mid-Palaeozoic, reflecting the “Ordovician Bioerosion Revolution” (sensu Wilson & Palmer 2006) and the “Mid-Palaeozoic Precursor of the Mesozoic Marine Revolution” (sensu Signor & Brett 1984), respectively, and in the Mesozoic, coinciding with the prominent “Marine Mesozoic Revolution” (sensu Vermeij 1977). This pattern mimics that of other micro- and macro-bioerosion trace fossils and is interpreted as a reflection of increased predation pressure and consequent infaunalisation. For extinction events, in turn, a differential effect is recorded in that the first four of the “Big Five” mass extinctions appear not to have had any noticeable effect on dendrinid ichnodiversity, whereas the end-Cretaceous mass-extinction resulted in a 77% drop following the Cretaceous peak ichnodiversity of 13 dendrinid ichnospecies.


Author(s):  
Daniel Sedorko ◽  
Luciano Alessandretti ◽  
Lucas Warren ◽  
Mariano Verde ◽  
Caio Rangel ◽  
...  

Author(s):  
Martin Lockley ◽  
R. Fleming ◽  
Kelly Conrad

Dinosaur National Monument (DINO) encompasses an area that has rocks with a high potential for preservation of vertebrate trace fossils, especially dinosaur tracks. The purpose of this research is to document the presence, type, and distribution of vertebrate trace fossils in Mesozoic rocks exposed in DINO. These rocks include the Moenkopi Formation, Chinle/Popo Agie Formation, Glen Canyon Sandstone, Carmel Formation, Entrada Sandstone, Morrison Formation, Cedar Mountain Formation, Dakota Formation, and Frontier Formation. This study will increase our knowledge of the stratigraphic and geographic distribution of vertebrate tracks as well as provide taxonomic, behavioral, and paleoenvironmental data. During the 1990 field season, reconnaissance of the western part of DINO revealed the presence of vertebrate trace fossils in the Chinle/Popo Agie Formation. In addition, our examination of the Moenkopi Formation suggests that vertebrate tracks are probably present in this unit. Locality information was also obtained for probable track-sites in the Carmel Formation, Entrada Sandstone, and Morrison Formation.


2018 ◽  
Vol 83 ◽  
pp. 194-206 ◽  
Author(s):  
David Javier Candia Halupczok ◽  
Maria Lidia Sánchez ◽  
Gonzalo Diego Veiga ◽  
Sebastián Apesteguía

2001 ◽  
Vol 172 (2) ◽  
pp. 237-244 ◽  
Author(s):  
Marcelo de la Fuente ◽  
France de Lapparent de Broin ◽  
Teresa Manera de Bianco

Abstract A new pleurodiran (side necked) turtle is described on material from the Upper Cretaceous of Patagonia, from sediments outcropping at Cerro Blanco, Yaminue Creek, Rio Negro, Argentina. The sediments are compared to those from the Pellegrini lake area referred to the middle Member of the Allen Formation, Upper Campanian-Lower Maastrichtian. Yaminuechelys gasparinii n.g., n.sp., is a pleurodiran turtle on the pelvis sutured to the shell and a chelid on the formula of cervical vertebrae and the lateral cheek emargination, deeply extended towards (as here) or up to the posterior emargination. It is the oldest record of a nearly complete skeleton of a chelid, long necked (elongated cervical vertebrae, lowered skull), and the first sufficiently known of the Chelodina-Hydromedusa group (elongated skull, lowered neural arch and centrum of the cervicals, low zygapophyses processes, strong polygoned decoration) and of the Hydromedusa sub-group (widened inner nares by reduced palatine ossification). The carapace is 41,8 cm long. It is more primitive than Hydromedusa (Eocene-Extant, South America) and retains primitive characters either still present or no more present in the other chelids of the Pseudemydura, Emydura and Phrynops groups (short necked) and Chelus group (long necked), representing the anterior clades of phyletic diversification [Gaffney, 1977], or evolutive grades, of the family. Such are plesiomorphic, relative to Hydromedusa, the less pronounced lateral skull emargination, wider and longer hyoid elements, wider nucal and cervical, this not drawn back, presence of lateral mesoplastra, not shortened bridge, straight borders of the not shortened and not widened posterior plastral lobe, amphicoelous sacrals and caudal vertebrae uniting amphicoelous, concavoplaty--(i.e. anteriorly concave, posteriorly flat) and procoelous or weakly procoelous elements. As Hydromedusa, Yaminuechelys n. g. retains primitive characters such as the long series of neurals, the very lateral attachment of the axillar and inguinal processes and the attachment of the pelvis, below pleural 8 (and 7 in the extant form) and a small part of the suprapygal, and the ischitatic sutures prolonged on the xiphiplastral points. It is distinguished by the apomorphic presence of a wide and week anterior carapacial notch. Yaminuechelys n.g., or aff. Yaminuechelys spp. are known in Patagonia by fragmentary remains in a dozen of Upper Cretaceous and two Palaeocene localities. Before them, chelids are known in the world only by undefined smaller forms from Lower Albian and Upper Albian-Cenomanian Patagonian localities. In Australia, they are known from Palaeocene-Lower Eocene (no Cretaceous data before) with already extant Australian diversified forms. Yaminuechelys n.g. demonstrates how long the diversification in chelids is realized in South Gondwana before the full break of the continents.


1984 ◽  
Vol 21 (2) ◽  
pp. 200-219 ◽  
Author(s):  
James D. Howard ◽  
Robert W. Frey

More than 20 trace fossil species occur in marine facies of the Cretaceous Star Point and Blackhawk formations in the Book Cliffs and Wasatch Plateau provinces of Utah. Major genera include Ancorichnus, Arenicolites, Aulichnites, Chondrites, Conichnus, Cylindrichnus, Medousichnus, Ophiomorpha, Palaeophycus, Planolites, Rosselia, Schaubcylindrichnus, Scolicia, Skolithos, Teichichnus, Teredolites, and Thalassinoides. Newly named taxa include Ancorichnus capronus, Medousichnus loculatus, and Rosselia chonoides.Most trace fossils occur in characteristic, albeit intergradational ichnofacies correlative with major lithofacies of regressive nearshore to offshore sequences. The latter include foreshore, foreshore–shoreface transition, shoreface, and offshore facies. Landward facies are typified by clean, well sorted, well stratified, sparsely burrowed sandstones. Seaward facies, except where interrupted by hummocky bedded sandstones, exhibit successively less pure, less well sorted and stratified, more intensely bioturbated, finer grained sandstones, siltstones, and mudstones.Characteristic ichnofacies and lithofacies in the Cretaceous of east-central Utah should provide potentially useful models for reconstruction of nearshore to offshore sequences elsewhere, especially in the Western Interior Region of North America.


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