New Ichnospecies of Cardioichnus from the Miocene of the Guadalquivir Basin,Huelva, Spain

A new ichnospecies of Cardioichnus, Cardioichnus reniformis isp. nov., is documented and described from marine strata of the Late Miocene of southwestern Spain. It is a bilobate resting trace with a heart‐shaped outline and is related to the work of a wedge‐shaped irregular echinoid of the spatangoid group.     

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.      

Lower Jurassic Arthropod Resting Trace from the Hartford Basin of Massachusetts,USA

Cheliceratichnus lockleyi ichnogen. nov. et ichnosp. nov. is a new ichnotaxon of arthropod resting trace (cubichnium) from the Lower Jurassic (Hettangian) East Berlin Formation in Holyoke, Massachusetts, USA. The trace fossil is preserved as showing many of the external anatomical features of the exoskeleton, which resemble those of some chelicerates, notably sun spiders (Solifugae). The resting trace is directly associated with a trackway of the ichnospecies Acanthichnus cursorius Hitchcock. This is the first described fossil resting trace of a solifugan-like arthropod, and the first direct evidence of a trackmaker of A. cursorius.     

Tonganoxichnus a new insect trace from the Upper Carboniferous of eastern Kansas

Upper Carboniferous tidal rhythmites of the Tonganoxie Sandstone Member (Stranger Formation) at Buildex Quarry, eastern Kansas, USA, host a relatively diverse arthropod-dominated ichnofauna. Bilaterally symmetrical traces displaying unique anterior and posterior sets of morphological features are well represented within the assemblage. A new ichnogenus, Tonganoxichnus, is proposed for these traces. T. buildexensis, the type ichnospecies, has an anterior region characterized by the presence of a frontal pair of maxillary palp impressions, followed by a head impression and three pairs of conspicuous thoracic appendage imprints symmetrically opposite along a median axis. The posterior region commonly exhibits numerous delicate chevron-like markings, recording the abdominal appendages, and a thin, straight, terminal extension. T. buildexensis is interpreted as a resting trace. A second ichnospecies, T. ottawensis, is characterized by a fan-like arrangement of mostly bifid scratch marks at the anterior area that records the head- and thoracic-appendage backstrokes against the substrate. The posterior area shows chevron-like markings or small subcircular impressions that record the abdominal appendages of the animal, also ending in a thin, straight, terminal extension. Specimens display lateral repetition, and are commonly grouped into twos or threes with a fix point at the posteriormost tail-like structure. T. ottawensis is interpreted as a jumping structure, probably in connection with feeding purposes. The two ichnospecies occur in close association, and share sufficient morphologic features to support the same type of arthropod producer. T. buildexensis closely mimics the ventral anatomy of the tracemaker, whereas T. ottawensis records the jumping abilities of the animal providing significant ethologic and paleoecologic information. The presence of well-differentiated cephalic, thoracic, and abdominal features, particularly in T. buildexensis, resembles the diagnostic tagmosis and segmentation of insects. Detailed analysis of trace morphology and comparison with described Paleozoic insect fossils and extant related forms suggest a monuran as the most likely tracemaker.     

Scorpionid Resting Trace from The Lower Permian of Southern New Mexico,USA

We describe an arthropod body impression associated with arthropod trackways of the ichnogenus Stiaria from the Lower Permian (upper Wolfcampian) Robledo Mountains Formation (Hueco Group) in the Prehistoric Trackways National Monument of southern New Mexico. The probable producer of these traces was a scorpion, and we name the likely scorpionid resting trace Alacranichnus braddyi, new ichnogenus and ichnospecies. There are no prior reports of scorpionid body impressions from terrestrial settings in the fossil record.     

A New Ichnospecies of Gyrolithes from the Austin Chalk,Upper Cretaceous,Texas, USA

Gyrolithes, a helical marine trace fossil, occurs in beds of the Austin Chalk near Waco, McLennan County, Texas. The new ichnospecies Gyrolithes texanus is characterized by unique morphology and wall construction. This discovery expands the current geographic and environmental range of Gyrolithes, extending this ichnogenus into the chalk-dominated beds of the Cretaceous of Texas. Irregular bedding features from the Gyrolithes locality indicate this section of the Austin Chalk was deposited within a storm-dominated depositional regime, interspersed with periods of quiescence which allow for firm ground formation and colonization by the trace maker. Occurrences of Gyrolithes have been associated by previous publications with marginal marine settings but not associated with storm deposits; therefore, this discovery constitutes an expansion of associated environment for this ichnogenus.     

Insights on the Behavior of Late Paleozoic Aquatic Crustaceans (Pygocephalomorpha?): Compound Trace Fossils from Western Argentina

We describe intergradations between the arthropod repichnial trace fossils Diplichnites gouldi (Gevers et al., 1971), Dendroidichnites Demathieu et al., 1992, and Monomorphichnus Crimes, 1970 with two distinct cubichnial traces, Gluckstadtella cooperi Savage, 1971 and Huilmuichnus santracruzensis new ichnogenus and ichnospecies. These compound ichnofossils are part of high ichnodiversity arthropod-dominated trace fossil associations from the Late Carboniferous Agua Escondida Formation of the San Rafael Basin (Argentina). The complex ichnotaxonomy of Diplichnites and the ichnospecies D. gouldi are discussed and some possible working solutions are proposed. The most likely producer of the compound trace fossils are the Pygocephalomorpha, a group of Late Paleozoic crustaceans that are recorded in nearby basins from Uruguay and Brazil. The compound trace fossils are used to infer a number of complex behaviors of pygocephalomorphs in a subaqueous setting, including caridoid (tail flip) or more primitive escape reactions, landing followed by resting and transient resting during normal walking. In addition, different gaits can be inferred from well-preserved D. gouldi, which can be correlated with contrasting trackway morphology.     

New trace fossils of termites (Insecta: Isoptera) from the late Eocene‐early Miocene of Egypt,and the reconstruction of ancient isopteran social behavior

Three new ichnogenera and five new ichnospecies are described for new trace fossils of termitaria (including associated gallery systems) of subterranean termites from upper Eocene through lower Miocene rocks of northern Egypt. All but two ichnospecies (Krausichnus trompitus, ichnogen, and ichnosp. nov., and A’, altus, ichnosp. nov.) show varying degrees of affinity to nests of the extant subterranean termite species Sphaerotermes sphaerothorax (Termitidae, Macro‐termitinae).

Termitichnus qatranii (Bown, 1982) is divided into two ichnospecies, the previously named T. qatranii, and a more generalized form, T. simplicidens, ichnosp. nov. Vondrichnus obovatus, ichnogen. and ichnosp. nov., is named for simple, possibly macrotermitine nests with oblate form, and Fleaglellius pagodus, ichnogen. and ichnosp. nov., records a nest form similar to V. obovatus, but one in which successive vertical growth by chamber apposition has produced a subterranean, tower‐like structure, reminiscent of that built by extant, epigeous Cubitermes. Krausichnus trompitus, ichnogen. and ichnosp. nov., and A’, altus, ichnosp. nov., record two unique nest architectures probably produced by unknown but related species of humivorous termites. The nest architecture expressed by Krausichnus is of wholly unknown affinity and is only distantly related in form to the ichnofossils of other termite nests known from the Tertiary of Egypt.

Study of the architecture of the nests of these ancient termites reveals details important in reconstructing the phylogeny of termite nests and documents two novel blueprints for chamber expansion and society budding in what were probably primitive Macrotermi‐tinae. It also indicates that at least two constructed edifices, earlier known only as epigeous manifestations of extant termite species, were almost certainly first developed by species living underground.

The extant Macrotermitinae are a subfamily of termites originally believed to have evolved in the post‐Eocene of the Ethiopian biogeo‐graphic region. We offer fossil evidence of four distinct, possibly macrotermitine structures from upper Eocene rocks. This evidence suggests that this termite subfamily (or at least their peculiar mode of nest construction) might have evolved considerably earlier, as it is already well established and exhibits several variants by the late Eocene in Egypt.     

The New Ichnogenus Flagrichnus—A Paleoenvironmental Indicator for Cold-Water Settings?

The new marine microboring ichnogenus Flagrichnus is described from Pleistocene mollusc shell beds of Rhodes (Greece) and the Costa Brava (Spain). Recent equivalents are studied in detail from the cold-temperate setting of the Swedish Kosterfjord area. Two ichnospecies are recognized: Flagrichnus profundus consists solely of a deeply penetrating gallery with a basal swelling while Flagrichnus baiulus comprises a single to multiple sack-shaped cavity at the base of a branching filamentous gallery that is penetrating deeply into the substrate. The traces are distributed from the euphotic zone down to aphotic depths suggesting (chemo)heterotrophic microendoliths and more specifically marine fungi as the trace makers. For Flagrichnus profundus, the thraustochytrid fungus Schizochytrium is recognized as its trace maker; for Flagrichnus baiulus, no definite candidate has been identified. While Flagrichnus profundus is distributed from tropical to arctic waters, Flagrichnus baiulus is only known from fossil and Recent non-tropical settings suggesting an applicability of this ichnospecies as an indicator for low paleotemperatures.     

THE FISH AND AMPHIBIAN SWIMMING TRACES UNDICHNA AND LUNICHNIUM, WITH EXAMPLES FROM THE LOWER PERMIAN OF NEW MEXICO, USA

Abstract: The ichnotaxonomy and stratigraphic, geographic and environmental distribution of fish (Undichna) and amphibian (Lunichnium) swimming traces are reviewed. The ichnospecies of Undichna consist of various combinations of sinusoidal waves of differing complexity. Some of the more complex ichnospecies are made up of elements of the simpler forms, and morphological subset relationships between them are presented. Such subset series represent potential taphoseries relationships (i.e. preservational variants that reflect, for example, undertrails), or series of minor behavioural variations. Such a system can be used to highlight that different ichnospecies occurring at a locality may be taphonomic or minor behavioural variants of each other. Caution should, therefore, be exercised before erecting new ichnospecies on the basis of limited material if its morphology is a subset of an existing ichnospecies. However, the naming of such simpler ichnospecies is valid if they represent a recurrent morphology, and it is valid to erect new ichnospecies whose morphology is not a subset of an existing ichnospecies. Specimens that demonstrate intergradation between ichnotaxa can be used to justify their synonomy. Ichnotaxonomic revisions reduce the number of ichnospecies in Undichna from 14 to nine. U. radnicensis, a highly variable ichnospecies, is synonymized with U. britannica on the basis of material from China that demonstrates they can intergrade. U. prava is a partial U. tricosta, which falls within the minimum diagnosis of U. simplicitas. U. gosiutensis is regarded as a subjective junior synonym of U. quina. U. westerbergensis, originally attributed to a ‘crossopterygian’ fish performing a tetrapod‐like gait, is reassigned as a distinct ichnospecies within Lunichnium because it demonstrates the same morphology, representing similar behaviour, albeit by a different producer. L. anceps and L. gracile are synonymized with L. rotterodium. New specimens of U. bina and L. rotterodium are also described from the Lower Permian Robledo Mountains Formation of southern New Mexico, USA.     

The Ichnogenus Kouphichnium and Related Xiphosuran Traces from the Steven C. Minkin Paleozoic Footprint Site (Union Chapel Mine), Alabama,USA: Ichnotaxonomic and Paleoenvironmental Implications

Abstract

The ichnogenus Kouphichnium and associated ichnofossils attributed to xiphosuran activity are here re-examined from samples collected from the Pennsylvanian-age Steven C. Minkin Fossil Site at the Union Chapel Mine, in Walker County, Alabama, USA. The large sample size offers an unique opportunity to evaluate some Kouphichnium ichnospecies. Thus, the morphological variability resulting from the taphonomic, ethological, taxonomic variability and underprint fallout are evaluated using this large sample set. Three morphotypes have been segregated from the material previously assigned to K. aspodon discovered at this and adjacent sites. Ichnospecies of Kouphichnium identified at the Union Chapel Mine site include: K. lithographicum, K. aspodon and two new ichnospecies (K. atkinsoni and K. minkinensis). Additionally, Kouphichnium-like traces that are associated with “jumper” traces have been previously misinterpreted as Kouphichnium and Selenichnites, respectively, and are excluded from this study, leaving them in open nomenclature as they will be the subject of a subsequent publication. We here redescribe the holotype of K. aspodon and designate lectoparatypes to better define the ichnospecies. New trace makers for some Kouphichnium ichnospecies are hypothesized, in contrast to the traditional xiphosuran attribution.     

Carboniferous Psammichnites: Systematic Re-Evaluation,Taphonomy and Autecology

The ichnogenus Psammichnites Torell 1870 includes a wide variety of predominantly horizontal, sinuous to looped, backfilled traces, characterized by a distinctive median dorsal structure. Though commonly preserved in full relief on upper bedding surfaces, some ichnospecies of Psammichnites may be preserved in negative hyporelief. Psammichnites records the feeding activities of a subsurface animal using a siphon-like device. Several ichnogenera reflect this general behavioral pattern, including Plagiogmus Roedel 1929 and the Carboniferous ichnogenera Olivellites Fenton and Fenton 1937a and Aulichnites Fenton and Fenton 1937b. Based on analysis of specimens from the United States, Spain, and the United Kingdom, three Carboniferous ichnospecies of Psammichnites are reviewed in this paper: P. plummeri (Fenton and Fenton, 1937a), P. grumula (Romano and Meléndez 1979), and P. implexus (Rindsberg 1994). Psammichnites plummeri is the most common Carboniferous ichnospecies and is characterized by a relatively straight, continuous dorsal ridge/groove, fine transverse ridges, larger size range, and non-looping geometric pattern. It represents a grazing trace of deposit feeders. Psammichnites grumula differs from the other ichnospecies of Psammichnites by having median dorsal holes or protruding mounds. The presence of mounds or holes in P. grumula suggests a siphon that was regularly connected to the sediment-water interface. This ichnospecies is interpreted as produced by a deposit feeder using the siphon for respiration or as a device for a chemosymbiotic strategy. Psammichnites implexus is characterized by its consistently smaller size range, subtle backfill structure, and tendency to scribble. Although displaying similarities with Dictyodora scotica, P. implexus is a very shallow-tier, grazing trace. Changes in behavioral pattern, preservational style, and bedform morphology suggest a complex interplay of ecological and taphonomic controls in Carboniferous tidal-flat Psammichnites. A first distributional pattern consists of guided meandering specimens preserved in ripple troughs, probably reflecting food-searching of buried organic matter concentrated in troughs. A second is recorded by concentration of Psammichnites on ripple crests and slopes. In some cases, the course is almost straight to slightly sinuous and closely follows topographic highs, suggesting a direct control of bedform morphology on trace pattern. Occurrences of Carboniferous Psammichnites most likely represent an opportunistic strategy in marginal-marine settings. Analysis of Carboniferous Psammichnites indicates the presence of a siphon-like device in the producer and reestablishes the possibility of a molluscan tracemaker.     

New ichnospecies of Linichnus Jacobsen & Bromley, 2009

Abstract

A new ichnospecies, Linichnus bromleyi, is described on bone substrate as the result of a very likely predator/scavenger interaction. L. bromleyi consists of a single groove with a non-serrated edge. This new ichnotaxon is compared with L. serratus which was defined as a single elongate serrate-edged groove. L. bromleyi has been identified over the surface of bones of marine mammals (in particular, cetaceans and pinnipeds) from two Pliocene outcrops of Andalusia, southern Spain. The new ichnospecies can be clearly related with a trophic interaction between sharks and marine mammals (mainly whales, dolphins and seals).     

Ophiomorpha irregulaire, Mesozoic trace fossil that is either well understood but rare in outcrop or poorly understood but common in core

The distinctive trace fossil, Ophiomorpha irregulaire, differs from other ichnospecies of Ophiomorpha in the so-called “meander maze” configuration of its horizontal course, and by the possession of unevenly distributed, elongated, tapering wall-lining pellets. The ichnospecies has been described, without doubt, from only two outcrop localities, both Late Cretaceous in age and both lying within the Cretaceous Western Interior Seaway. Only a single, almost convincing example of the trace fossil has been reported elsewhere, in a Lower Jurassic outcrop in Italy. Apart from this last occurrence, the distribution of O. irregulaire in outcrop suggests that the trace fossil has a restricted time span and geographical range. In contrast, O. irregulaire is identified more commonly in cores, and these occurrences show no clear geographical restrictions and are reported in sediments of Jurassic as well as Cretaceous age. Outcrop exposures of Jurassic and Cretaceous sediments have been extensively studied by ichnologists and if the large, eye-catching O. irregulaire were as common as is suggested by core material, then the trace fossil would not have escaped notice in outcrop.Identification of the trace fossil in core is generally made on the basis of two-dimensional, vertical sections. The characteristic meander maze form cannot be seen in this view, and the identification is thus based almost entirely on the special shape of the lining pellets. As is well known, the identification of large trace fossils in the restricted format of core lacks the security of extensively exposed trace fossils in outcrop. The discrepancy between age and geographic distribution of O. irregulaire in outcrop and core suggests that some misidentification is occurring in core analysis.     

Ichnology of the Early Cambrian Tal Group,Nigalidhar Syncline,Lesser Himalaya,India

Though trace fossils have been recorded from the Tal Group of the Krol-Tal Belt by earlier workers, most of the records are at generic level only. This paper describes, in detail, 24 ichnospecies from 20 ichnogenera, some of which are being reported for the first time, from the Ganog and Koti Dhaman sections of the Nigalidhar Syncline, H.P. Based on the ichnostratigraphic and ichnofabric analyses these ichnofossils have been categorized into three ichnoassemblages, namely Palaeophycus-Phycodes, Daedalus-Phycodes, and Cruziana Ichnoassemblages. An attempt has also been made for correlation of the Tal sections with other Precambrian-Cambrian sections of the world.     

The trace fossil Circulichnis as a record of feeding exploration: New data from deep-sea Oligocene–Miocene deposits of northern Italy

Circulichnis is a puzzling, ring-like trace fossil preserved on bedding planes. It is represented mostly by its type ichnospecies C. montanus, which is characterized by an evenly circular or elliptical course. A new ichnospecies, C. ligusticus, is distinguished based on material from deep-sea Oligocene–Miocene deposits of the Tertiary Piemonte Basin, NW Italy. It shows a winding or irregular course. A new model of Circulichnis is proposed as an exploration burrow produced mostly by the trace makers of Helminthoidichnites, Gordia, or Helminthopsis, as it moved to a different sediment layer to checking its feeding utility. This type of behaviour occurred already by the Ediacaran and is common in marine, mostly deep-sea bedded sediments. The trace makers belong mostly to polychaetes in marine sediments and to oligochaetes in continental sediments.     

A New Ichnospecies of Arthrophycus from the Late Carboniferous (Pennsylvanian) of Michigan,USA

A unique ichnofossil assemblage from Pennsylvanian-age sandstones near Eaton Rapids, Michigan, USA, comprises straight-to-curved traces preserved in convex hyporelief, with the transverse ridges and median grove associated with the ichnogenus Arthrophycus. The Michigan traces show some branching or pseudo-branching (also known from other Arthrophycus specimens) and are among the smallest structures (millimeters in diameter) attributed to this ichnogenus. The orientation of the Michigan Arthrophycus burrows is distinct from other ichnospecies of this taxon in the pronounced co-planar alignment of the burrows, as opposed to the multiplanar, interweaving, “bundled” nature typical of the ichnogenus. On this basis we assign the Michigan specimens to a new ichnospecies of Arthrophycus. The “paralleling behavior” of the new taxon may reflect a strategy of the tracemaker to avoid previous burrows and reflect differences in resource availability or current energy. This new taxon supports previous records of the occurrence of this ichnogenus in Upper Carboniferous strata.     

New occurrences of Ichniotherium and Striatichnium from the Lower Permian Kildare Capes Formation,Prince Edward Island,Canada: palaeoenvironmental and biostratigraphic implications

Abstract: Tracks and trackways of the vertebrate ichnotaxon Ichniotherium sphaerodactylum and a trace of the invertebrate ichnotaxon Striatichnium bromackerense are described for the first time in association outside of Europe. The tracks are identified as I. sphaerodactylum based on their characteristic rounded digit ends, the ovoid sole‐pad of the pedal imprint and the increase in digit lengths from digits I–IV, and the invertebrate trace is identifiable as S. bromackerense based on the band‐like systems of distally bifurcated striae. The tracks of I. sphaerodactylum are the largest known to date and represent rare evidence of large‐bodied terrestrial vertebrates in the Kildare Capes Formation of Prince Edward Island, Canada. Morphometric differences between ichnospecies of Ichniotherium and other ichnospecies previously collected from Prince Edward Island are examined in a multivariate analysis, and results suggest that the distance between the manus and pes of the same imprint pair, the width of pace and the length of certain digits is useful for species identification. The association between I. sphaerodactylum and S. bromackerense was previously known only from the Bromacker quarry, Tambach Formation, Germany, which is interpreted as a seasonally dry, semi‐arid upland environment. The co‐occurrence of these traces suggests that the Eldon locality of Prince Edward Island is similar in depositional environment to the Bromacker quarry in Germany, and allows for comparison of these two localities for the first time. As diadectids are thought to be the trackmakers of Ichniotherium, the Eldon locality of the Kildare Capes Formation may, with further work, be considered as another example of the rare, herbivore‐dominated palaeoenvironment, which is generally uncharacteristic of the Early Permian of North America.