Taenidium Barretti Research Articles

Paleobiology and paleoecology of an arid–semiarid Miocene South American ichnofauna in anastomosed fluvial deposits

Miocene deposits of the Toro Negro Formation in La Rioja province, Argentina, host a rich vertebrate and invertebrate ichnofauna. Trace fossils are recorded from the lower part of the Lower Member of the Toro Negro Formation at Quebrada de La Troya. This succession consists of sandstone, intraformational breccia, mudstone and few conglomerate deposited in sandy anastomosing fluvial systems developed under a semi-arid climate. The invertebrate ichnofauna is composed of meniscate trace fossils ( Taenidium barretti, Scoyenia gracilis), dwelling structures ( Palaeophycus tubularis) and grazing trails ( Helminthopsis hieroglyphica). The vertebrate ichnofauna includes avian ( Fuscinapeda sirin, incumbent footprint, slender anisodactyl footprint) and mammalian footprints ( Macrauchenichnus rector, cf. Venatoripes riojanus, small heteropod footprint, kidney-like footprints, and oval impressions). Tetrapod footprints and rare Palaeophycus and Helminthopsis are preserved on the top of exposed sandbars. Crevasse splay deposits preserve abundant meniscate trace fossils and dwelling tubes (e.g. Taenidium, Scoyenia and Palaeophycus) ascribed to the Scoyenia ichnofacies. Two suites of invertebrate trace fossils can be differentiated: meniscate backfill structures ( T. barretti) and other burrows ( P. tubularis) without ornamentation, developed in a soft substrate, and striated traces ( S. gracilis), that crosscut the former, developed in a firmer substrate. The Toro Negro depositional system displays a high preservation potential for tracks due to seasonal flooding events, which rapidly buried the footprints. The favorable preservational conditions and good exposure of the track-bearing surface enable us to interpret the track assemblage of the Toro Negro Formation as a sample of the original tetrapod fauna that inhabited that region at central-western Argentina during the Miocene. The identification of possible trackmakers is utilized in this work as a useful tool that contributes to our understanding of the ancient environment. The paleoichnocommunity is characterized by the number of trackmakers and the relative abundance of each type of footprints. A new method to measure footprint abundance is proposed; the relative bioturbed area (RBA). This measurement provides numerical characterization of the degree of bioturbation of the whole tracking surface caused by each ichnotaxa. The tetrapod fauna indicated by the footprint record was compared with the body fossil record of the Toro Negro Formation. These records overlap in some ways, and in other ways they are complementary. The presence of large and medium to small ground sloth, proterotheriid litopterns, caviid rodents, and birds is pointed out by both body fossils and ichnofossils. Body fossils include remains attributed to dasypodids, glyptodontids, and abrocomid rodents. Ichnofossils indicate the presence of macraucheniid litopterns and three types of birds: shorebirds, perching birds, and large cursorial birds.

Complex palaeosol ichnofabrics from Late Jurassic–Early Cretaceous volcaniclastic successions of Central Patagonia, Argentina

Late Jurassic–Early Cretaceous volcaniclastic continental deposits from central Patagonia, Argentina were analyzed for an integral characterization of palaeosol ichnofabrics. These units contain complex continental ichnofabrics that were also recorded in other late Jurassic–late Miocene extended volcaniclastic successions from Patagonia. According to a recently proposed method, ichnofabric, pedofabric and original bedding of selected intervals were measured separately in order to determinate the degree in which the deposits are affected by soil features besides the ichnofabrics. Four recurrent ichnofabrics were recognized in studied palaeosols: the Loloichnus, large Taenidium– Beaconites, diffuse boxwork, and Dagnichnus ichnofabrics. The Loloichnus ichnofabric is characterized by sub-vertical Loloichnus baqueroensis and subordinate, similarly arrenged large Taenidium barretti and Beaconites coronus. L. baqueroensis is a crayfish dwelling structure while large T. barretti and B. coronus are assigned to locomotion of the same organisms. Root traces are additional components of this ichnofabric. The large Taenidium– Beaconites ichnofabric is formed by large, irregular and curved T. barretti and B. coronus and by L. baqueroensis in low proportion. This ichnofabric is also assigned to crayfish activity. The diffuse boxwork ichnofabric is characterized by a pervasive and intricate three-dimensional boxwork of burrows; occasionally joined to subspherical chambers (possible Castrichnus). The diffuse boxwork is interpreted as an earthworm burrow system and the associated chambers are probably for aestivation. Rare and scattered discrete trace fossils in this ichnofabric include L. baqueroensis, T. barretti and B. coronus. The Dagnichnus ichnofabric is formed by Dagnichnus titoi, root traces and, subordinately, Loloichnus baqueroensis, Cellicalichnus meniscatus and tangled groups of meniscate burrows. D. titoi and C. meniscatus has been interpreted as crayfish breeding structures and the tangled groups of meniscate burrows are probably related to juvenile crayfish activity. The studied ichnofabrics were formed in weakly to moderately developed palaeosols in lowland areas with frequent reworking of pyroclastic material by unconfined flows. The recognized ichnofabrics show that in Patagonia, for the Late Jurassic–Early Cretaceous times, crayfishes and earthworms were the dominant soil organisms and, along with plants, rapidly colonized deposits exposed subaerially. After sediment deposition and with high soil moisture content or high water table crayfishes probably crawled in moist sediments forming the large Taenidium– Beaconites ichnofabric. With a better drained soil profile or lower water tables, the Loloichnus ichnofabric, representing the dwelling structures of adult crayfishes, overprinted the previous ichnofabric. The diffuse boxwork ichnofabric, usually located in the uppermost portion of palaeosols, correspond to extensive fossil earthworm burrow systems. The Dagnichnus ichnofabric occurs in very weakly developed palaeosols and probably reflects the optimal palaeoenvironmental conditions for breeding crayfish.

Paleohydrological significance of trace fossil distribution in Oligocene fluvial-fan-to-lacustrine systems of the Ebro Basin, Spain

The ichnological study of fluvial fan and lacustrine Oligocene deposits in the NE Ebro Basin has allowed the recognition of three ichnoassemblages having a strong correlation with depositional facies associations. Lacustrine deposits lack bioturbation due to the hydrologically closed character of the lake that caused hypersalinity and made it inhospitable for benthic life. Terminal lobe deposits of the fluvial fan, which were sedimented in low wetland areas around the lake, bear a moderately diverse ichnoassemblage dominated by horizontal Taenidium barretti, Cochlichnus anguineus and bird footprints ( Gruipeda isp.). This assemblage can be assigned to the 'shorebird ichnofacies', a subset of the Scoyenia ichnofacies that characterizes the subaerial part of low-energy shore areas. Crevasse splay deposits in medial fluvial fan areas present a different assemblage also belonging to the Scoyenia ichnofacies. It includes most of the trace fossils found in the terminal lobes, except for the bird tracks, plus very abundant vertical burrows ( Taenidium barretti and unnamed ornamented burrows). The presence of deep-tier traces of terrestrial invertebrates is consistent with the more proximal fan setting, having greater relief and consequently a lower mean groundwater position than lowland areas. Fluvial channels only bear irregularly clustered tunnel structures of unknown affinity formed after abandonment of the channel. Thus, trace fossil assemblages are mostly controlled by the position and fluctuations of water tables, which are the cause for their composite nature.

Palaeoecology of an Early Permian playa lake trace fossil assemblage from Castle Peak, Texas, USA

The Early Permian Choza Formation of the Clear Fork Group at Castle Peak in Texas, USA, contains a diverse and remarkably abundant trace fossil assemblage comprising exquisitely preserved arthropod trackways ( Diplichnites gouldi types A and B, Diplichnites isp. A and B, Lithographus isp. and cf. Kouphichnium isp.), striated trails ( Cruziana problematica) and isolated resting traces ( Rusophycus carbonarius and R. furcosus), surface or shallow subsurface grazing trails or burrows ( Gordia indianensis, Helminthoidichnites tenuis, Treptichnus isp., a nodular trail and unilobate epichnial trails), backfilled deposit-feeding burrows ( Planolites beverleyensis), meniscate backfilled burrows ( Taenidium barretti), horizontal branching networks, and tetrapod trackways ( Dromopus palmatus, Erpetopus willistoni, Varanopus curvidactylus and cf. Amphisauropus isp.). Trace fossils formed in, and around the margins of, a shallow, ephemeral (playa) lake within an alluvial plain, and provide evidence of temporary communities, comprising arthropods, most notably notostracan branchiopod crustaceans, as well as euthycarcinoids, myriapods, insects, and tetrapods, including protorothyridid, captorhinid and araeoscelid reptiles and rare amphibians. Periodic influxes of water into the alluvial plain filled various depressions, creating temporary habitats and flourishes of life and activity. The trace fossil assemblage is typical of the Scoyenia ichnofacies, and is similar to other assemblages from a range of different transitional subaqueous to subaerial settings, indicating that the distribution of trace fossils is not inextricably linked to the depositional setting itself, but rather to the environmental factors that arise. Such diverse trace fossil assemblages probably reflect relatively long-lived ephemeral water bodies, whereas more impoverished examples probably represent shorter-lived ephemeral water bodies. Assemblages such as Castle Peak, with abundant delicate arthropod trackways, probably reflect low energy conditions, conducive to the presence of an abundant vagile epifauna and the preservation of their trackways, whereas assemblages with open vertical burrows tend to lack arthropod trackways and probably reflect higher energy conditions. Trace fossil assemblages dominated by arthropod and tetrapod trackways may represent fleeting preservation windows following sheetfloods on floodplains.

Invertebrate ichnofossils from the Adamantina Formation (Bauru Basin, late Cretaceous), Brazil

The Bauru Group is a sequence at least 300 m in thickness, of Cretaceous age (Turonian- Maastrichtian), located in southeastern Brazil (Bauru Basin), and consists of three formations, namely Adamantina, Uberaba and Marilia. Throughout the Upper Cretaceous, there was an alternation between severely hot dry and rainy seasons, and a diverse fauna and flora was established in the basin. The ichnofossils studied were found in the Adamantina Formation outcrops and were identified as Arenicolites isp., ?Macanopsis isp., Palaeophycus heberti and Taenidium barretti, which reveal the burrowing behavior of the endobenthic invertebrates. There are also other biogenic structures such as plant root traces, coprolites and vertebrate fossil egg nests. The Adamantina Formation (Turonian-Santonian) is a sequence of fine sandstones, mudstones, siltstones and muddy sandstones, whose sediments are interpreted as deposited in exposed channel-bars and floodplains associated areas of braided fluvial environments.

Lithofacies distribution of invertebrate and vertebrate trace-fossil assemblages in an Early Mesozoic ephemeral fluvio-lacustrine system from Argentina: Implications for the Scoyenia ichnofacies

This paper discusses the lithofacies distribution and ichnotaxonomic assignment of invertebrate, vertebrate and plant trace fossils in an Early Mesozoic ephemeral fluvio-lacustrine system from northwest Argentina. The overall palaeoenvironment is envisaged as a distal, low-gradient fluvio-lacustrine setting under semi-arid climate, similar to a terminal fan. Depositional lobes (facies association A) are composed of distributary ribbon channels (facies A1), and associated pond and sheetflood deposits (facies A2). Lowlands between depositional lobes (facies association B) contained poorly drained floodplain zones similar to wetlands (facies B1) and shallow closed lakes (facies B2). Depositional lobes were fringed by playa-lake settings (facies association C), including mudflats (facies C1) that are partially eroded by ephemeral fluvial channels (facies C2). The ichnofauna of the Santo Domingo Formation displays high ichnodiversity (30 trace fossil types) and includes 5 trace fossil assemblages that are linked to sedimentary facies. These trace fossil assemblages are highly distinctive as half of the recognised trace fossil types are assigned to different assemblages. The ephemeral fluvial channel assemblage (facies A1 and C2) displays the lower ichnodiversity ( n = 6) and includes Skolithos linearis, Diplichnites sp., Palaeophycus tubularis, Taenidium barretti, Dicynodontipus sp. and footprints in cross-section. The floodplain pond assemblage (facies A2) shows the higher ichnodiversity ( n = 15) and is composed of Diplichnites sp., Helminthoidichnites tenuis, P. tubularis, Rusophycus carbonarius, S. linearis, Spongeliomorpha carlsbergi, T. barretti, appendage marks, burrows with brush-like features, epichnial bilobed traces, hypichnial bilobed ridges, bird-like footprint type A, tridactyl footprints, footprints preserved in cross-section, and small epichnial rounded pits. The poorly drained floodplain assemblage (facies B1) is of moderate ichnodiversity ( n = 10) and consists of H. tenuis, S. carlsbergi, ? Spongeliomorpha sp., imbricated backfilled burrow fillings, root trace type A, Tetrasauropus sp., bird-like footprint type A, large pentadactyl footprints, tridactyl footprints, and footprints preserved in cross-section. The high ichnodiversity ( n = 13) nearshore lacustrine assemblage (facies B2) is the only assemblage that lacks vertebrate traces, and is composed of Cochlichnus anguineus, Cruziana problematica, H. tenuis, Palaeophycus heberti, P. striatus, P. tubularis, Scoyenia gracilis, S. carlsbergi, T. barretti, epichnial bilobed traces, hypichnial bilobed ridges, root trace type B, and scratch marks. The intermediate ichnodiversity ( n = 9) mudflat assemblage (facies C1) is typified by the largest ichnodiversity of vertebrate tracks and includes H. tenuis, P. tubularis, S. carlsbergi, Dicynodontipus sp., Tetrasauropus sp., bird-like footprints of types B and C, large pentadactyl footprints, and tridactyl footprints. The trace fossil assemblages from Santo Domingo Formation are typical representatives of the Scoyenia ichnofacies. The distinctiveness of the studied trace fossil assemblages suggests that a future division of the Scoyenia ichnofacies would be possible, provided that occurrences of invertebrate, vertebrate and plant trace fossils in definite sedimentary facies are considered. The subdivision of the Scoyenia ichnofacies into recurrent groups of trace fossils (ichnosubfacies) with a palaeoecological and palaeoenvironmental meaning can be based on two approaches: distinction of associations of vertebrate tracks and recognition of ichnocoenoses related to substrates with different degrees of water saturation and firmness. The first approach can be based on an evaluation of the recurrent vertebrate ichnoceonoses used to recognise vertebrate ichnofacies. In this way, some of the candidate vertebrate ichnofacies are proposed as subdivisions of the Scoyenia ichnofacies. The second approach is based on the identification of crosscutting relationships between trace fossils and between trace fossils and sedimentary structures within some trace fossil assemblages. Using this methodology, it is possible to define distinct assemblages of trace fossils: a “pre-desiccation suite” with structures lacking ornamentation and developed in a soft substrate and a “desiccation suite” typified by striated traces that crosscut the former. These trace-fossil assemblages help to characterise the changes in organism–sediment interaction during progressive desiccation of a water-lain substrate. Additional neoichnological studies are necessary to assess the exact meaning of different trace fossil features in terms of substrate consistency.

Trace fossils from marginal lacustrine deposits of the Cretaceous Jinju Formation, southern coast of Korea

Trace fossils from the Cretaceous Jinju Formation of the south coast of Korea occur in interbedded medium- to fine-grained sandstone of a moderate-energy lake shoreface, and mudstone–shales of a periodically exposed low-energy shallow lake, and interfingerings of both of the above. The trace fossils are represented by Beaconites antarcticus, Beaconites coronus, Cochlichnus anguineus, Diplichnites ( Octopodichnus) cf. didactylus, Diplichnites type A, Diplichnites isp., Helminthopsis hieroglyphica, Palaeophycus sulcatus, Palaeophycus tubularis, Planolites annularis, Planolites beverleyensis, Protovirgularia dichotoma, Skolithos magnus, Taenidium barretti, and sauropod tracks. The Diplichnites specimens are among the first arthropod trackways recorded from the Cretaceous. Two of the four trackway-bearing ichnocoenoses present in the study area are considered representative of composite ichnofacies. Sinusoidal burrows or trails and simple irregular interface burrows or trails probably formed in wet, possibly submerged, soupground–softground conditions in low- or medium-energy lake margins, and represent the Mermia ichnofacies. Trackways and meniscate burrows probably formed on the subsequently subaerially exposed lake margins following lake regression and represent an overprinting by the Scoyenia ichnofacies. The other two trackway-bearing ichnocoenoses are from the Scoyenia ichnofacies alone.

Fluviodeltaic sedimentology and ichnology of part of the Silurian Grampians Group, western Victoria

The mid‐Silurian Major Mitchell Sandstone of the Grampians Group outcrops at Mt Bepcha, western Victoria, represent a prograding fluviodeltaic sequence comprising four lithofacies and five ichnofacies. The stratigraphically lowest Interbedded Sandstone/Siltstone Facies is characterised by thin sandstone and siltstone beds with soft‐sediment deformation and scours with gravelly lag deposits. This lithofacies contains Thalassinoides, Palaeophycus, Rhizocorallium and intrastratal burrows, together indicative of the Cruziana Ichnofacies, and is interpreted as a shallow‐marine depositional environment on a low‐energy delta front with minor tidal influences. The overlying Massive Sandstone Facies lacks silt, and consists of predominantly massive and some plane‐laminated sandstone, abundant Skolithos linearis , rare Palaeophycus and a single small Cruziana problematica ; the trace‐fossil assemblage is assigned to the Skolithos Ichnofacies. This facies is believed to have been deposited in a marine high‐energy shoreface environment with continuously shifting sands, affected by periodic flooding events from the mouth of a nearby river. Above this is the Trough Cross‐bedded Facies, which contains trough cross‐bedding with gravelly lag deposits, a northwest palaeocurrent direction and large Taenidium barretti burrows (Burrowed Ichnofacies). This facies also contains abundant plane‐laminated sandstone with a northeast‐southwest palaeocurrent direction and ichnofossils of Scoyenia and Daedalus , representing the Scoyenia Ichnofacies. The Trough Cross‐bedded Facies is interpreted to have been deposited in shallow low‐sinuosity channels by overbank‐flooding events, most likely on a delta plain. The uppermost facies, the Plane‐laminated Facies, contains thin beds of current‐lineated, plane‐laminated graded coarse to fine sandstone that preserve arthropod trackways (Arthropod Ichnofacies). This facies was deposited on a periodically sheet‐flooded, subaerially exposed delta plain.

Cretaceous Nonmarine Trace Fossils from the Hasandong and Jinju Formations of the Namhae Area, Kyongsangnamdo, Southeast Korea

Nonmarine strata of the Cretaceous Hasandong and Jinju formations of the Sindong Group of the Namhae area, Kyongsangnamdo, southeast Korea, contain relatively diverse and abundant ichnofaunas including domichnia, fodinichnia, pascichnia, and repichnia. These ichnofaunas are systematically described herein and three ichnocoenoses, namely the Skolithos, Palaeophycus, and Chondrites ichnocoenoses, are defined based on their paleoenvironmental occurrence.The Skolithos ichnocoenose characterizes tabular laminated sandstone facies deposited on fluvial channel levées. It is dominated by infaunally produced ichnotaxa, particularly Skolithos magnus Howell, Planolites montanus Richter and Chondrites isp. type A, with reduced numbers of Skolithos verticalis (Hall) Taenidium barretti (Bradshaw) and rare examples of Circulichnus montanus (Vyalov), Cochlichnus anguineus Hitchcock, Helminthopsis abeli Książkiewicz, Helimthopsis hieroglyphica Wetzel and Bromley, Laevicyclus isp., Planolites beverleyensis (Billings), Skolithos isp., Spirodesmos isp., Thalassinoides suevicus (Rieth), and rhizoliths.The Palaeophycus ichnocoenose characterizes floodplain environments and occurs in purple mudstones and associated massive sandstone facies of crevasse-splay deposits and dark gray to green shale facies of abandoned channels. Palaeophycus tubularis Hall and Planolites montanus Richter are the most characteristic ichnotaxa, while Beaconites coronus (Frey, Pemberton and Fagerstrom), Planolites annularius Walcott, Skolithos magnus Howell, Thalassinoides paradoxicus (Woodward), and sauropod and ornithopod tracks also occur but in reduced numbers.The Chondrites ichnocoenose occurs in dark gray to black mudstones deposited in marginal lacustrine environments. It is dominated by Chondrites isp. type B. with associated Beaconites antarcticus Vyalov, Helminthopsis hieroglyphica, Palaeophycus tubularis, Skolithos magnus, Taenidium barretti, and Torrowangea rosei Webby.The three ichnocoenoses recognized herein cannot be satisfactorily assigned to currently defined nonmarine ichnofacies, suggesting that existing models of such ichnofacies are in need of additional refinement.

Ichnology, Sedimentology and Paleontology of Eocene Calcareous Paleosols From a Palustrine Sequence, Argentina

Other| February 01, 2002 Ichnology, Sedimentology and Paleontology of Eocene Calcareous Paleosols From a Palustrine Sequence, Argentina RICARDO N. MELCHOR; RICARDO N. MELCHOR 1CONICET & Universidad Nacional de La Pampa, Av. Uruguay 151, 6300 Santa Rosa, La Pampa, Argentina Search for other works by this author on: GSW Google Scholar JORGE F. GENISE; JORGE F. GENISE 2CONICET & Departamento de Icnología, Museo Paleontológico “Egidio Feruglio”, Av. Fontana 140, 9100 Trelew, Chubut, Argentina Search for other works by this author on: GSW Google Scholar SERGIO E. MIQUEL SERGIO E. MIQUEL 3CONICET & Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Av. Ángel Gallardo 470, 1405 Buenos Aires, Argentina Search for other works by this author on: GSW Google Scholar PALAIOS (2002) 17 (1): 16–35. https://doi.org/10.1669/0883-1351(2002)017<0016:ISAPOE>2.0.CO;2 Article history accepted: 05 Jul 2001 first online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation RICARDO N. MELCHOR, JORGE F. GENISE, SERGIO E. MIQUEL; Ichnology, Sedimentology and Paleontology of Eocene Calcareous Paleosols From a Palustrine Sequence, Argentina. PALAIOS 2002;; 17 (1): 16–35. doi: https://doi.org/10.1669/0883-1351(2002)017<0016:ISAPOE>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyPALAIOS Search Advanced Search Abstract Integrated analysis of the ichnology, sedimentology, geochemistry, and fossil content of three trace fossil-bearing calcareous paleosols from the early Eocene Gran Salitral Formation is used to reconstruct the detailed paleoenvironmental and paleoecological setting of this insect-dominated ichnofossil association. This continental sequence, located in southwestern La Pampa province (Argentina), is composed of palustrine marls and minor lacustrine mudstones and sandstones arranged in shallowing-upward cycles. The ichnologic association is the first comprehensively described from a palustrine sequence and could be used for future comparisons with other similar assemblages. The ichnofauna is dominated by bee cells, Celliforma germanica, C. roselli, and Rosellichnus isp.; Teisseirei barattinia, an insect trace fossil that is redescribed and recorded for the first time outside its type locality; Taenidium barretti; and Skolithos linearis. The ichnologic association also includes ovoid structures, ornamented burrow fillings, and plant trace fossils (rootlets, rhizoliths, and a tree / shrub stump). Abundant freshwater (Pomacea sp.) and terrestrial gastropods (Plagiodontes spp., Bostryx sp., and Bulimulus sp.) are used to characterize the paleoenvironmental setting. The weakly developed paleosols are interpreted as Inceptisols, developed in a low-gradient lake margin periodically exposed to pedogenesis with low (probably saline) vegetation and sparse shrubs. They developed under a semi-arid and warm climate (mean annual temperature higher than 20°C). Short saline / alkaline conditions were prevalent during lake lowstands, accompanied by incipient karst development. The association of trace fossils is attributed provisionally to the Coprinisphaera ichnofacies, although its distinctive features and recurrence in time and space may deserve recognition as a separate ichnofacies. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Upper Triassic (Keuper) non-marine trace fossils from the Haßberge area (Franconia, south-eastern Germany)

Various trace fossils from the Hassberge Formation and the Lowenstein Formation (Middle Keuper, Upper Triassic) of the Hasberge region are described. Twenty-three different forms have been identified, 17 of which are named, includingCruziana pascens n. isp.,Lockeia cunctator n. isp., andRusophycus versans n. isp.Lockeia siliquariaJames, 1879,L. amygdaloides (Seilacher, 1953),L. triangulichnusKim, 1994, andL. elongata (Yang, 1984) are revised and synonymized under the oldest available name,L. siliquariaJames, 1879.Rusophycus eutendorfensis (Linck, 1942) andR. carbonariusDawson, 1864 are revised. The diagnosis ofPolykladichnusFursich, 1981 is emended, and a diagnosis forHelminthoidichnitesFitch, 1850 is given for the first time. Among the described ichnotaxa,Skolithos ispp.,Rusophycus carbonarius, andTaenidium barretti are the most common forms. The trace fossil association is typical of theScoyenia ichnofacies, which indicates non-marine, periodically or completely inundated environments, such as floodplains and lake margins. Two palaeoichnocoenoses are identified. One ichnocoenosis, dominated byCruziana problematica, cf.Polykladichnus isp., andSkolithos isp. B characterizes margins of trough cross-bedded sandstones. Another ichnocoenosis, dominated byRusophycus versans n. isp.,Taenidium barretti,Scoyenia gracilis andSkolithos isp. A is related to ephemeral lake deposits. Taxonomic recommendations for the use of hitherto described and figured invertebrate Keuper trace fossils from Germany are given.

A Gondwanan Coastal Arthropod Ichnofauna from the Muth Formation (Lower Devonian, Northern India): Paleoenvironment and Tracemaker Behavior

Other| April 01, 2001 A Gondwanan Coastal Arthropod Ichnofauna from the Muth Formation (Lower Devonian, Northern India): Paleoenvironment and Tracemaker Behavior ERICH DRAGANITS; ERICH DRAGANITS 1Institut für Geologie, Universität Wien, Althanstrasse 14, A-1090 Vienna, Austria Search for other works by this author on: GSW Google Scholar SIMON J. BRADDY; SIMON J. BRADDY 2Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, United Kingdom Search for other works by this author on: GSW Google Scholar DEREK E. G. BRIGGS DEREK E. G. BRIGGS 2Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, United Kingdom Search for other works by this author on: GSW Google Scholar PALAIOS (2001) 16 (2): 126–147. https://doi.org/10.1669/0883-1351(2001)016<0126:AGCAIF>2.0.CO;2 Article history accepted: 18 Nov 2000 first online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation ERICH DRAGANITS, SIMON J. BRADDY, DEREK E. G. BRIGGS; A Gondwanan Coastal Arthropod Ichnofauna from the Muth Formation (Lower Devonian, Northern India): Paleoenvironment and Tracemaker Behavior. PALAIOS 2001;; 16 (2): 126–147. doi: https://doi.org/10.1669/0883-1351(2001)016<0126:AGCAIF>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentBy SocietyPALAIOS Search Advanced Search Abstract The recent discovery of abundant trace fossils in the Lower Devonian Muth Formation (Pin Valley, Spiti, northern India) contributes to our understanding of the diversity and distribution of Early Devonian arthropod activities in a marginal marine environment. The ichnoassemblage consists of abundant Palmichnium antarcticum and Diplichnites gouldi with rarer Diplopodichnus biformis, Taenidium barretti, Didymaulichnus cf. lyelli, Didymaulyponomos cf. rowei, Selenichnites isp., and vertical burrows of unclear affinity. The abundance of trackways enables the documentation of size- and gait-variations among producers of single trackway ichnotaxa. The paleoenvironment of the Muth Formation is interpreted as a barrier island system. Four different facies associations are recognized; arthropod trackways occur only in beach to coastal dune environments (facies association 2). Most of the Palmichnium and Diplichnites trackways are interpreted as subaerial. The abundance and frequently sub-parallel orientation of the Palmichnium antarcticum trackways, predominantly perpendicular to the paleocoastline, suggest that stylonurid eurypterids, which are interpreted as their producer, were migrating across the shoreline and climbing up slip faces of barrier island dunes. The similarity of this ichnofauna to others in marginal marine environments of similar age in Antarctica and Australia allows the identification of a recurrent Lower Devonian ichnocoenosis around the margins of eastern Gondwana. You do not currently have access to this article.

Large Phymatoderma in pliocene slope deposits, northwestern Ecuador: Associated ichnofauna, fabrication, and behavioral ecology

Phytnatoderma is a complex, branching biogenic structure that is seldom mentioned in the ichnologic literature, although it may have been misidentified recently as “Zonarites” and large pellet‐filled “Chondrites”. The ichnogenus is usually interpreted as the product of subsurface deposit‐feeding animals. Well‐preserved examples from Pliocene slope mudstone in Ecuador are assignable to P. granulatum (Schlotheim, 1822). These structures are typically 30–40 cm in overall diameter; consist of outward‐branching, horizontal to subhorizontal, overlapping tunnels grouped in bundles; and have tunnel fills consisting of pelleted volcanic ash. The Ecuadorian Phymatoderma occur with a moderately rich ichnoassemblage that includes Alcyonidiopsis ichnosp., Chondrites intricatus, several kinds of Phycodes‐like structures, Phycosiphon incertum, Planolites ichnosp., Rorschachichnus amoeba, Scolicia ichnosp., Taenidium barretti, and Zoophycos ichnosp. Benthic foraminiferids and geologic context point to deposition on the upper trench slope, ca. 3–4 Ma. Ecuadorian Phymatoderma are large, structurally intricate burrow systems that not only represent surface deposit feeding and below‐surface pellet stowage/food caching, but also behavior that apparently included revisiting runnels to utilize the pellets for food, in response to a variable trophic regime. Together with other morphologically intricate, ethologically complex marine ichnogenera (e.g., Zoophycos, Chondrites, Paleodictyon), Phymatoderma deserves special attention as a complex animal artefact, rather than being considered merely a snapshot of a single or dominant behavior. Such complicated structures appear to record deliberate activity to restructure habitats, modulate natural disturbances, and to control trophic resources.