Recent borings in limestone cobbles from Marloes Bay, southwest Wales

Limestone clasts from the beach at Marloes Sands, southwest Wales, contain slender, straight to sinuous borings cross-cut by younger, clavate borings. The former were probably produced by sipunculids or polychaetes; the latter preserve shells of the boring bivalve Gastrochaena dubia (Pennant). Unusually, the calcareous linings of the clavate bivalve borings extend into many of the slender worm borings. Such linings are considered part of the hard parts of the producing bivalve, but the chance association of the two morphologies of borings has led to the lining becoming intimately associated with both of them. The modified linings of the bivalve borings have a similar morphology to the crypt of certain clavagellid bivalves, perhaps presenting an analogue for the morphology of a pre-clavagellid, boring ancestor.     

Skimming the surface with Burgess Shale arthropod locomotion

The first arthropod trackways are described from the Middle Cambrian Burgess Shale Formation of Canada. Trace fossils, including trackways, provide a rich source of biological and ecological information, including direct evidence of behaviour not commonly available from body fossils alone. The discovery of large arthropod trackways is unique for Burgess Shale-type deposits. Trackway dimensions and the requisite number of limbs are matched with the body plan of a tegopeltid arthropod. Tegopelte, one of the rarest Burgess Shale animals, is over twice the size of all other benthic arthropods known from this locality, and only its sister taxon, Saperion, from the Lower Cambrian Chengjiang biota of China, approaches a similar size. Biomechanical trackway analysis demonstrates that tegopeltids were capable of rapidly skimming across the seafloor and, in conjunction with the identification of gut diverticulae in Tegopelte, supports previous hypotheses on the locomotory capabilities and carnivorous mode of life of such arthropods. The trackways occur in the oldest part (Kicking Horse Shale Member) of the Burgess Shale Formation, which is also known for its scarce assemblage of soft-bodied organisms, and indicate at least intermittent oxygenated bottom waters and low sedimentation rates.     

Erratum

Abstract

Bored relict log-grounds are locally abundant in hybridized glauconitic fossiliferous muddy sands and associated carbonate concretions in the Eocene Tallahatta Formation, southern Alabama. Log-ground ichnofabrics are dominated by commonly stenomorphic, calcite-lined, variably filled clavate borings assigned to Teredolites longissimus and attributed to teredinid bivalves. Differences in axial morphology and occurrence of accessory tube features (e.g., retrusive calcite caps, concamerations, etc.) within and between borings (1) reflect ontogeny and variable behavioral responses to substrate overcrowding and/or degradation and (2) help to assess previously proposed models for teredinid bivalve life histories. Wood preservational state and significant textural variability among tube-filling sediments reflect extended residence time of log-grounds at or near the sediment-water interface. Like similar accumulations in other marine shelf sequences, the abundance of Teredolites-bearing log-ground accumulations in the Tallahatta can be attributed to both an influx pulse of xylic material and sediment starvation associated with transgression. The low ichnologic diversity (T. longissimus and very rare Thalassinoides) of these and other marine log-grounds may reflect a limited medley of wood-inhabiting tracemakers, but also likely reflects poor substrate preservation associated with physical reworking, biochemical degradation, and the bioerosion process itself.     

Non-marine Teredolites from the Middle Eocene of southern England

Middle Eocene, non-marine sediments from southern England contain examples of Teredolites borings in two contrasting palaeoenvironmental settings, viz.: (A) as in situ borings in an allochthonous lignite in an abandoned river channel and (B) as bored logs in cross-bedded fluvial sandstones of probable point-bar origin. The lignite is 0.30 m thick, of which the upper 0.20 m is intensely bored. Rounded pebbles of ?charcoal at its base also show small borings. A log in a fluvial sandstone shows densely-packed. radial club-shaped borings. now filled with sandstone. The wood substrate has subsequently been oxidized away. To our knowledge, this is the first detailed account of Teredolites from an ancient freshwater setting.     

The glossifungites ichnofacies in the area of its nomenclatural archetype,lviv, Ukraine

An occurrence of "Glossifungites saxicava”; Lomnicki (=Rhizocorallium jenense Zenker) is redescribed from its type area in Lviv, Ukraine, after more than 100 years since its first report. This trace fossil densely penetrates a Miocene transgressive surface cut in Cretaceous marlstones. Its occurrence is restricted to the top layer of the marlstones, where it was formed in a firmground typical of the Glossifungites ichnofacies. Most probably, the trace fossil was produced during a period of non‐deposition shortly before and at the beginning of deposition of Miocene strata by opportunistic suspension‐feeding organisms, possibly crustaceans.     

HISTORY OF ICHNOLOGY—Ichnological Eccentrics: The Curious Case of Dr. Joseph Barratt of Middletown,Connecticut

Joseph Barratt was a British-born and educated physician who settled in the United States in 1819. He had a great interest in natural history, collecting both plants and insects and studying geology, mycology, ornithology, chemistry, meteorology, Native Americans, and local history. He was apparently a man of great energy and ambition but one who could not focus to see a project to completion. Barratt was active in the early history of the discovery of vertebrate footprints in the Newark Supergroup in the eastern United States but latter developed some very strange theories regarding the age and significance of these deposits. In his latter years, Barratt's mental state deteriorated and he became even more obsessed with trying to publicize his outlandish theories. Dr. Joseph Barratt is remembered in ichnology for basically two things; he sold Edward Hitchcock a superb specimen of vertebrate tracks; and he may have the most elaborate ichnological tombstone ever constructed.     

Taphonomy of Logs Bored with Teredolites longissimus Kelly and Bromley in the Danian (Lower Paleocene) of West Greenland

The boring Teredolites longissimus Kelly and Bromley is recorded infesting silicified logs in the Fossil Wood Member, Kangilia Formation (Lower Danian, Paleocene) of West Greenland. There are two morphologies of T. longissimus, probably representing two different episodes of invasion of the wood. The initial borings of Morphology 1 are large, deformed to an elliptical section, and confined to a direction of boring parallel to sub-parallel to the wood grain. Morphology 2 borings are less common, narrower and shorter, sinuous, markedly crosscut the grain of the wood and, where preserved intact, retain their circular cross-section. They were a later infestation than Morphology 1. Following the infestation by Morphology 1, the logs were deformed, probably by weight of overburden, and then reworked, when some of them were infested by Morphology 2 producers. Final burial was followed by brittle collapse of some Morphology 2 borings and lithification before further deformation could occur. The occurrence of T. longissimus in deeper water deposits close to a land mass with a steep slope indicates that transport in the marine realm was minimal before waterlogging.     

Mayfly Burrows in Firmground of Recent Rivers from the Czech Republic and Poland,with Some Comments on Ephemeropteran Burrows in General

U-shaped, pouch-like burrows with parallel limbs, covered with short scratches arranged in sets, occur in the thalweg of the Oh?e river in NW Czech Republic. Similar, but smaller burrows with rare scratches, not arranged in sets, occur in the thalweg of the Drw?ca river in N Poland. Probably, they are produced by larvae and/or nymphs of Palingenia and Polymitarcis (Ephoron), respectively. In both localities, they burrowed in firmground surfaces at shallow depths. The burrowed surfaces were emerged during low water levels. A review of recent mayfly burrows shows that they are 1) U-shaped pouches with parallel limbs and septum, which may be covered with short scratches and are oriented perpendicular to the bottom, irrespective of its inclination, or 2) wide U-shape burrows with divergent limbs, which may be branched. In the fossil record, the ichnogenera Fuersichnus, Asthenopodichnium, and Rhizocorallium are partly ascribed to mayfly burrows, but their comparison to the recent burrows shows that such interpretations are somewhat problematic. The mayfly burrows are potentially good indicators of aquatic, non-marine, well oxygenated, clean water environments.     

A new ichnospecies of Fuersichnus from the Cretaceous of Antarctica and its paleoecologic and stratigraphic implications

A new ichnotaxon is recognized in the Hidden Lake Formation, Upper Cretaceous of James Ross Island, Antarctica. Fuersichnus striatus consists of horizontal to subhorizontal, isolated or loosely clustered, U‐shaped, curved to banana‐like burrows, characterized by distinctive striations parallel to the trace axis. It is interpreted as a dwelling structure probably produced by crustaceans or polychaetes. This recording of Fuersichnus extends its stratigraphic range from the Triassic‐Jurassic to the Cretaceous and its environmental setting from nonmarine to marine environments. F. striatus typified consolidated, but unlithified substrates. Accordingly, it must be considered a member of the Glossifungites ichnofacies.     

Bivalve Wood Borings of the Ichnogenus Teredolites Leymerie from the Bohemian Cretaceous Basin (Upper Cretaceous,Czech Republic)

Finds of fossil wood with bivalve wood borings (Teredolites clavatus and T. longissimus) occur in various facies and presumed sedimentary settings of the platform, shallow-marine Bohemian Crectaceous Basin. The basin comprises areas with sandy-dominated sediments, with marl and clay-dominated sediments, areas with predominat sandy-marly rocks, and finally areas dominated by calcareous nearshore sediments. Teredolites clavatus is common in fossil wood of sandstones, originating in beach or deltaic settings; marl and clay-dominated rock frequently bear wood fragments densely bored by Teredolites longissimus. When accompanied by evidence of marine environments as body fossils, glauconite or typical trace fossils, most of the wood fragments are bored. The presence/absence of borings in wood fragments can be considered the most reliable and easily useable criterion of distinction of marine settings in sandy sediments of the margin of the Bohemian Cretaceous Basin.