Lower Cretaceous (Albian) shell-armoured and associated echinoid trace fossils from the Sácaras Formation, Serra Gelada area, southeast Spain

The Sácaras Formation (Albian, Lower Cretaceous) of the Serra Gelada succession (Prebetic of Alicante), southeast Spain, comprises carbonate‐rich, upwards thickening parasequences in which many types of trace fossils have been identified. The present study focuses on two types of tubular trace fossil characterized by features of their external coating. The first type is represented by a shell‐covered, structured trace fossil, up to 4?cm in diameter and 40?cm in length, built horizontally, from rectilinear (type 1) to gently curved (type 2), which envelopes an unstructured pipe of grey silty sediment. The coating is characterized by imbricated, flat particles, mainly orbitolinid foraminifers and other planar bioclasts, forming thin concentric layers; in cross section the bioclasts produce a typical plumed structure. This trace fossil represents a new ichnogenus and ichnospecies, here named Ereipichnus geladensis. Particle arrangement of the external coating is similar to that of terebelloid tubes, but Ereipichnus is a horizontal trace fossil, whereas structured worm tubes are vertical. The second type is a grain‐coated trace fossil, tubular in shape, with a simple internal structure. The coating is often reddish with respect to the neighbouring dark grey sediment and shows a slightly coarser‐grained texture, which envelopes the internal muddy pipe. This type, which yielded echinoids, was produced by irregular or heart‐shaped sea‐urchins (spatangoids) and is attributed to Scolicia or Cardioichnus. Facies analysis of the Serra Gelada succession with Ereipichnus and Scolicia or Cardioichnus locally shows other types of branched trace fossils (primarily represented by different forms of Thalassinoides) and bioturbation is developed in tiers, increasing upwards in abundance and diversity.     

Taxonomic reassessment ofBolonia Meunier, 1886 (trace fossil) based on new material from the type area in Boulonnais, northern France

The ichnospeciesBolonia lata Meunier, 1886 is a straight, bilobate trace fossil with a somewhat heart-shaped outline in cross-section. It has previously been reported from various localities mainly from the Jurassic by different authors under various names such asGyrochorte, Scolicia, orProtovirgularia. Because none of these previous determinations fully agrees with the trace fossils’ morphology, the ‘forgotten name’ is reintroduced, and due to a lack of type material a neotype from the type area of Boulonnais, France is proposed. The ichnogenus is currently represented only by one ichnospecies,B. lata Meunier, 1886. Diagnostic criteria ofBolonia and morphologically related trace fossils such asScolicia, Gyrochorte, Bichordites, “Taphrhelminthopsis nelsoni”, andProtovirgularia are discussed, the synonymy ofB. lata is provided and finally a discussion on the possible producer ofBolonia is given.      

湖北三峡地区埃迪卡拉系灯影组“蝌蚪状”遗迹化石*

遗迹化石是埃迪卡拉纪存在两侧对称动物最有力的证据。但多数埃迪卡拉纪遗迹化石为简单、水平的表面爬迹或潜穴。在湖北三峡地区灯影组石板滩段含典型埃迪卡拉软躯体化石的地层中新发现一类形态特别的化石,呈蝌蚪状,一端膨大,一端细管状。通过对化石形态、同位素分析以及沉积学特征的研究,说明该化石为遗迹化石,而不是实体化石。蝌蚪状化石为一种复合迹,垂向活动形成球状的膨大端,平行藻席层活动形成近于水平的潜穴,反映了造迹生物垂向切穿藻席层并沿藻席层进行觅食的行为。该发现说明了在埃迪卡拉纪晚期已有两侧对称动物开始形成较为复杂的潜穴。     

Evidence for targeted elasmobranch predation on thalassinidean shrimp in the Miocene Taliao Formation,NE Taiwan

Terrestrial and marine invertebrate organisms both leave records of their activities in the sediment in the form of trace fossils, at least during certain stages of their ontogeny. In contrast, trace fossils produced by vertebrate organisms are scarce, although terrestrial trace fossils provide exclusive insights into the social behaviour of their producers. In the marine realm, vertebrate trace fossils are relatively rare, difficult to identify and problematic to interpret. However, in certain settings, observations on serendipitously preserved and exposed trace fossils can shed light on the predatory behaviour of marine vertebrates. In Miocene outer shelf to nearshore sandstones of the Taliao Formation in NE Taiwan, large numbers of bowl‐shaped trace fossils can be observed. Morphology and size range (diameter typically 10–30 cm, average depth around 10 cm) of these trace fossils agree well with feeding traces of modern stingrays, and the trace fossil Piscichnus waitemata, which has been attributed to bottom feeding rays. Stingrays direct a jet of water from their mouths to excavate a bowl‐shaped pit to expose their prey. In the material filling the excavated bowl, broken pieces of two other common trace fossils, Ophiomorpha and Schaubcylindrichnus, are often found, and in a number of cases, vertical shafts of Ophiomorpha surrounded by dispersed pieces of wall material have been observed. In contrast, surrounding sediment rarely contains this kind of broken pieces of wall material. These observations clearly indicate that stingrays specifically targeted the producers of the trace fossils: thalassinoid crustaceans and worms, respectively. The targeted predation of these relatively deep burrowers furthermore suggests that the rays used their electroreceptive organs to locate the prey; as such, direct targeting of buried prey only based on olfactory senses has been shown to be ineffective in experiments with extant myliobatiform rays.     

An ethological framework for animal bioerosion trace fossils upon mineral substrates with proposal of a new class, fixichnia

Animal bioerosion trace fossils upon mineral substrates are analyzed from the point of view of the Seilacherian ethological classification. Several of the currently accepted ethological classes: cubichnia, fugichnia, repichnia, fodinichnia, agrichnia, calichnia and aedificichnia are not represented in these substrates. This fact points out a lower behavioral diversity of hard substrate trace fossils when compared with soft sediment trace fossils. Bioerosion traces can be classified in just five classes: domichnia, pascichnia, equilibrichnia, praedichnia and fixichnia. Fixichnia is here erected to gather superficial etching scars resulting from the anchoring of fixation of sessile epiliths by means of a soft or skeletal body part. Praedichnia and fixichnia are exclusive of the bioerosion realm.     

A VARVITE ICHNOCOENOSIS FROM THE DWYKA SERIES OF NATAL

Arthropod trails and resting impressions are described from an horizon in the Dwyka Series of northern Natal. The sediments have been deposited in freshwater periglacial lakes and are of late Carboniferous or early Permian age. All the trails and resting impressions appear to have been made by crustacean arthropods, and it is suggested that syncarids or peracarids were probably responsible. Numerous fish traces are also present in this ichnocoenosis but these are still being studied by several workers and are not described below. The trace fossils described herein are Umfolozia sinuosa gen. et sp. nov., Diplichnites govenderi sp. nov., Diplichnites sp., Protichnites sp. A, Protichnites sp. B, Gyrochorte sp., Isopodichnus sp., Kingella natalensis gen. et sp. nov., and Gluckstadtella cooperi gen. et sp. nov.     

Reassessment of sediments and trace fossils from old red sandstone (Lower devonian) of Dunure,Scotland, described by John Smith (1909)

In 1909 John Smith, a Scottish naturalist and geologist,described 23 «genera and 51 «species of trace fossils from small patches of sediment associated with andesite lava flows at Dunure, Ayrshire. He interpreted the traces as evidence of a diverse invertebrate fauna which inhabited small pools and fissures in the lava surface between eruptions. Smith's collection (c. 300 specimens) was presented to the British Geological Survey, Edinburgh but has remained largely unstudied.Re-examination of the Smith collection shows thatit came from 3 separate localities which differ in composition of the ichnofaunas, associated sediments and sedimentary structures. Arthropod trackways dominate the ichnofauna occurring in laminated siltstone frequently with ripple marks and foam marks suggesting formation in shallow lacustrine conditions. Preservational and behavioural analysis of trace fossils reveals about 10 valid ichnogenera of locomotion and swimming trackways, resting traces, feeding trails but few burrows. Presence of early terrestrial arthropod traces is uncertain. Palaeocological interpretation is of ephemeral lakes in distal braid-plain situation subject to subsurface invasion of andesite lava producing fluidization and deformation of wet sediment. The Dunure ichnocoenosis shows unique diversity of Devonian arthropod trace fossils.     

Infaunal augurs of the Cambrian explosion: An Ediacaran trace fossil assemblage from Nevada,USA

Morphologically complex trace fossils, recording the infaunal activities of bilaterian animals, are common in Phanerozoic successions but rare in the Ediacaran fossil record. Here, we describe a trace fossil assemblage from the lower Dunfee Member of the Deep Spring Formation at Mount Dunfee (Nevada, USA), over 500 m below the Ediacaran–Cambrian boundary. Although millimetric in scale and largely not fabric‐disruptive, the Dunfee assemblage includes complex and sediment‐penetrative trace fossil morphologies that are characteristic of Cambrian deposits. The Dunfee assemblage records one of the oldest documented instances of sediment‐penetrative infaunalization, corroborating previous molecular, ichnologic, and paleoecological data suggesting that crown‐group bilaterians and bilaterian‐style ecologies were present in late Ediacaran shallow marine ecosystems. Moreover, Dunfee trace fossils co‐occur with classic upper Ediacaran tubular body fossils in multiple horizons, indicating that Ediacaran infauna and epifauna coexisted and likely formed stable ecosystems.     

Turbulence,displacement, death and worms: a day in the life of a fluvial Carboniferous bivalve

Kane, I.A. 2010: Turbulence, displacement, death and worms: a day in the life of a fluvial Carboniferous bivalve. Lethaia, Vol. 43, pp. 381–395. In the Pennsylvanian Rough Rock Flags and Rough Rock of northern England trace fossils attributed to the non‐marine bivalve Carbonicola are found. Carbonicola, recorded by Lockeia and associated trace fossils, lived a semi‐infaunal lifestyle and thus were influenced by both the sediment in which they were hosted, and the currents which supplied their nutrients and oxygen. A number of palaeocurrent indictors are commonly associated with Lockeia: (1) downstream inclination of vertical burrows; (2) palaeoflow‐parallel orientation of long axes; (3) steeper scouring and higher sediment surface on the upstream side; and (4) diffuse lamination downstream of the trace or more widespread downstream erosion. Semi‐infaunal, Carbonicola bivalves were partly exposed to the prevailing flow and acted as bed defects; flow separation and acceleration enhanced flow turbulence around the bivalve leading to erosion and the development of a variably developed fan‐shaped zone of scour immediately downstream. Disturbance and destabilization of sediment in this way may have affected bivalves immediately downstream, plausibly explaining the relatively regular spacing pattern of individual or clustered Lockeia, exposed on bedding planes and revealed by nearest neighbour analyses. Bivalves that did not survive high‐energy flow events were either trapped within the sediment, or transported downstream and deposited in lower energy environments within the otherwise high‐energy deposits of the Rough Rock.     

Ichnology of Lower Jurassic beach deposits in the Shemshak Formation at Shahmirzad,southeastern Alborz Mountains,Iran

A 19 m thick package of well-sorted lowermost Jurassic (Hettangian-Lower Sinemurian?) sandstones within the Shemshak Formation of the southeastern Alborz Mountains displays features characteristic of foreshore to upper shoreface environments such as tabular bedding, low-angle lamination, trough cross-stratification, parting lineation, and oscillation ripples. In contrast to most other beach successions recorded in the literature the sandstones contain a trace fossil assemblage characterised by low abundance but comparatively high diversity. The assemblage, comprising 14 ichnotaxa, is dominated by Palaeophycus heberti, Rhizocorallium irregulare, Gyrochorte comosa, and Parahaentzschelinia surlyki. Contrary to predictions, which assume a dominance of suspension-feeders in such high-energy environments, the trace fossil assemblage represents a variety of ethological groups ranging from suspension-feeders to deposit-feeders, detritus-feeders, scavengers, and a possible trap constructor (Ctenopholeus), whereby deposit-feeders predominate. This anomaly is explained by a high amount of organic detritus in the sediment, indicated by abundant plant material, and a position of the beach in the vicinity of a river mouth.     

Fossil bee nests,coleopteran pupal chambers and tuffaceous paleosols from the Late Cretaceous Laguna Palacios Formation,Central Patagonia (Argentina)

The Late Cretaceous Laguna Palacios Formation in Central Patagonia (San Jorge Basin), southern South America, is composed of tuffaceous deposits supplied by periodical volcanic ash falls partly reworked by rivers, on broad plains. Variations in ash-fall rates allowed the formation of stacked, mature paleosols, which are one of the most characteristic features of this formation. The mature paleosols show well-developed horizons, ped structure and bear an intricate network of trace fossils mostly produced by small roots and invertebrates. Two different insect trace fossils could be recognized in this formation: sweat bee nests and coleopteran pupal chambers. Fossil bee nests are composed of inclined tunnels with cells attached to them by means of short necks, a typical construction of bees of the subfamily Halictinae. Similar halictine constructions were reported from the Cretaceous of the USA. Coleopteran pupal chambers are discrete, ovoid structures, having an internal cavity with a smooth surface, and an outer wall of lumpy appearance composed of different layers of soil material. They are commonly constructed by the larvae of different families of Coleoptera. Similar trace fossils were previously reported from the Asencio Formation (Late Cretaceous–Early Tertiary) of Uruguay and from the Djadokhta Formation of Mongolia (Late Cretaceous). These trace fossils constitute some of the only paleontological data from the Laguna Palacios Formation, allowing inferences about its paleoecology, paleoclimatology and paleogeography. Ecological preferences of Halictinae, as well as some features of the nests, suggest a temperate, seasonal climate and an environment dominated by low vegetation for the Laguna Palacios Formation, which is also compatible with sedimentologic and pedogenic evidence. The morphology of the nests, typical of North American halictinae, adds more evidence to the hypothesis of the existence of faunal interchange between North and South America by the Late Cretaceous. The fossil nests constitute some of the oldest evidence of bees in the fossil record, the third known record of bees of Cretaceous age and the first for the Southern Hemisphere. The two traces described are, together with those of Dakota and the Gobi Desert, the only trace fossils from paleosols of Cretaceous age that can be certainly attributed to insects.     

Ichnology of deep‐sea fan overbank deposits of the Ganei slates (Eocene,Switzerland)— a classical flysch trace fossil locality studied first by Oswald Heer

Ganei (Switzerland) is a classical locality for trace fossils. At this site, Heer (1877) described a large number of trace fossils, several of which were new taxa. The trace fossils occur in thin‐bedded turbidites in which the basal divisions of the Bouma sequence are typically absent; the turbidites are assigned to the Ganei Slates and are Eocene in age. They are interpreted to have been deposited in an overbank environment within an upper to middle fan area distal to a channel. Two trace‐fossil associations occur: the first (I) is characterized by bulldozing organisms producing biodeformational structures, Scolica, and Nereites irregularis; the second (II) association shows a distinct tiering pattern with near‐surface graphoglyptids and a mixed layer with simple tubes such as cf. Palaeophycus and Planolites, plus patterned tubes such as Nereites cirrinalis, and Chondrites. Deeper turbidite layers were colonized by Chondrites and Gyro‐phyllites. All trace fossils show a normal size spectrum compared to previously studied trace‐fossil associations, so the degree of oxygenation probably did not influence the composition of either trace‐fossil association. Seafloor sediment was probably soft and did not affect the trace‐fossil associations. Sedimentation rate and event frequency did not change and are estimated to have been in a range of 5–10 cm/1000 years and 2–5 events per 1000 years, respectively. The composition of trace‐fossil associations I and II is therefore interpreted to have been controlled by the benthic food content being higher for trace‐fossil association I than for II.     

LATE PRECAMBRIAN TRACE FOSSILS FROM NEW SOUTH WALES

Seven trace-fossil species are described from the upper part of the Torrowangee Group (Upper Proterozoic) of western New South Wales, and a variety of other traces are illustrated. A few forms occur in the Fowlers Gap Beds, and a more diverse and abundant fauna is recorded from the stratigraphically higher Lintiss Vale Beds. Virtually all the traces are preserved in the plane of bedding, as semi-reliefs. The named trace fossils all come from the Lintiss Vale Beds, and are as follows: Planolites ballandus sp. nov., Planolites? sp., Cochlichnus serpens sp. nov., Gordia? sp., Torrowangea rosei gen. et sp. nov., Phycodes? antecedent sp. nov., and Curvolithus? davidis sp. nov. Three of these species are regarded as feeding burrows (endogene), and are thought to represent the activity of infaunal, worm-like deposit feeders. Others may be either feeding burrows or crawling trails. There are also a few impressions which seem to be rest marks. A discussion of the significance of the trace-fossil occurrences is presented.     

贵州台江早、中寒武世凯里组的遗迹化石

凯里组发现遗迹化石９属１４种，主要是以ＰｈｙｃｏｄｅｓｐｅｄｕｍＳｅｉｌａｃｈｅｒ为主的遗迹群落，重要的遗迹属如：Ｃｏｃｈｌｉｃｈｎｕｓ，Ｇｏｒｄｉａ，Ｍｏｎｏｍｏｒｐｈｉｃｈｎｕｓ，Ｏｌｄｈａｍｉａ，Ｐｌａｎｏｌｉｔｅｓ，Ｔｒｅｐｔｉｃｈｎｕｓ等常见于世界各地寒武纪Ｃｒｕｚｉａｎａ遗迹相。根据遗迹化石表明凯里组沉积于盐份、含氧量正常，海水能量中等的浅海软基底潮下带环境。     

Digital image treatment applied to ichnological analysis of marine core sediments

Characterization of trace fossils in marine core sediments is, most times, difficult due to the weak differentiation between biogenic structures and the host sediment, especially in pelagic and hemipelagic facies. This problem is accentuated where a high degree of bioturbation is associated with composite ichnofabrics. Simple methods are presented here based on modifications to image features such as contrast, brightness, vibrance, saturation, exposure, lightness, and color balance using the software Adobe Photoshop CS6 (Adobe Systems, San Jose, CA, USA) to enhance visibility and thus allow for a better identification of the trace fossils. Adjustments involving brightness, levels and vibrance generally give better results. This approach was applied to marine cores of pelagic and hemipelagic sediments obtained from the Integrated Ocean Drilling Program Expedition 339, Site U1385. Enhancing the digital images facilitates ichnological analysis through improving the visibility of weakly observed trace fossils, and in some cases revealing traces not detected previously.     

湖南新化下石炭统遗迹化石及其沉积环境

鉴定了产自湖南新化地区早石炭世碳酸岩沉积中的遗迹化石6属(Zoophycus, Chondrites, Phycodes, Planolites, Palaeophycus, Skolithos)16种.并根据岩性实体与遗迹化石以及沉积构造等特征,划分为2个沉积亚相、21个微相、19个遗迹相.     

How spatangoids produce their traces: relationship between burrowing mechanism and trace structure

Kanazawa, K. 1995 11 30 How spatangoids produce their traces: relationship between burrowing mechanism and trace structure.
Two spatangoid echinoids, Echinocardium cordatum and Lovenia elongata , were allowed to produce their traces in poorly and well-sorted sediments in aquaria. In poorly sorted sediments they formed distinct traces, comparable to fossil traces. Sorting of sediment occurred during transportation by the lateroventral spines and brought about characteristic patterns in grain size at the bottoms of the burrows and in redeposited sediment, which made the traces visible. Differences in the burrowing mechanism between E. cordatum and L. elongata are reflected in their trace structures. E. cordatum formed a laminated backlill structure which resulted from periodic accumulation of excavated sediment behind it, while L. elongata simply pushed excavated sediment by compression to the posterior sides of the test, so that their traces lack a distinct laminated structure and the width of the trace becomes larger than that of the animal. In well-sorted sediment, the echinoids burrowed in the same way as in poorly sorted sediment, but no visible trace was produced other than a drain tube. These observations reasonably explain some characteristic modes of occurrence of fossil spatangoid traces. Their different morphological expressions depend on sediment texture and the uneven lithification of traces. Spatangoids, trace, burrowing mechanism .     

The proterozoic and earliest cambrian trace fossil record; patterns, problems and perspectives

The increase in trace fossil diversity across the Neoproterozoic-Cambrianboundary often is presented in terms of tabulations of ichnogenera.However, a clearer picture of the increase in diversity andcomplexity can be reached by combining trace fossils into broadgroups defined both on morphology and interpretation. This alsofocuses attention on looking for similarites between Neoproterozoicand Cambrian trace fossils. Siliciclastic sediments of the Neoproterozoicpreserve elongate tubular organisms and structures of probablealgal origin, many of which are very similar to trace fossils.Such enigmatic structures include Palaeopascichnus and Yelovichnus,previously thought to be trace fossils in the form of tightmeanders. A preliminary two or tripartite terminal Neoproterozoic tracefossil zonation can be be recognized. Possibly the earliesttrace fossils are short unbranched forms, probably younger thanabout 560 Ma. Typical Neoproterozoic trace fossils are unbranchedand essentially horizontal forms found associated with diverseassemblages of Ediacaran organisms. In sections younger thanabout 550 Ma a modest increase in trace fossil diversity occurs,including the appearance of rare three-dimensional burrow systems(treptichnids), and traces with a three-lobed lower surfaces.     

Trace fossils of animal‐plant interactions and “pseudointeractions” from maletín (Bohemian cretaceous basin,Czech Republic)

Old collections of the Upper Cretaceous flora at Maletín yield examples of trace fossils of plant‐arthropod interactions, comparable with recent insect galls. Grooves and ridges, often preserved on leaves at this locality, are (in contradiction to several previous authors) interpreted as traces of burrowing organisms, which originated in soft sediment adjacent to the plant remains lying on a lake floor or buried in the substrate. The leaves functioned in the sediment at the time of burrowing and/or during compaction of the substrate as distinctive laminar bodies with specific physical characteristics and therefore they enabled the preservation of some aspects of ichnofabric otherwise invisible in the surrounding strata.