Traces Of Bioerosion Research Articles

О ПАЛЕОЭКОЛОГИЧЕСКОЙ ЦЕННОСТИ КОЛЛЕКЦИЙ НИЖНЕФРАНСКИХ БЕСПОЗВОНОЧНЫХ ГЛАВНОГО ДЕВОНСКОГО ПОЛЯ В ФОНДАХ ГОРНОГО МУЗЕЯ

The article describes two groups of facies most widely represented in the collections of Lower Frasnian invertebrates of the Main Devonian Field in the Mining Museum (hardgrounds and pelecypod banks). The presence of three types of hardgrounds has been established, differing in the nature of the original bottom and the time of exposure of each hardground, and hence structural and textural features of rocks and systematic composition of oryctocenoses. The first type is crinoidal limestone with an extensive complex of sclerobionts and traces of bioerosion by Trypanites Mägdefrau, an uneven surface and a visually almost complete absence of impregnation. In hardgrounds of this type, three generations of sclerobionts are distinguished, namely: abiogenic substrates (first), incrustators of the remains of organisms of the first generation (second), and bioerosion organisms (third). The second type is micritic limestone with a smooth glass-type surface, a small complex of sclerobionts and traces of bioerosion by Trypanites Mägdefrau. The third type is pelecypod limestones with an uneven surface, isolated sclerobionts, numerous traces of bioerosion by Trypanites Mägdefrau and strong ferruginous impregnation. For the most widespread hardgrounds of the first type, the presence of specific taphofacies has been established, characterized by good preservation of organic remains of the first generation, an almost complete absence of organic remains of the second generation, and a complete absence of bioerodible organisms. The appearance of such taphofacies is due to the short exposure time of the hardground and the beginning of a rapid process of new accumulation immediately after the appearance of the first organisms of the second generation. The presence of such taphofacies emphasizes the importance of distinguishing taphofacies in certain paleofacies and certain types of oryctocenoses. In the oryctocenoses of pelecypod shells, three morphological and ethological types of cornulitids have been established. The most representative settlements of cornulithids were characteristic of calcareous clay soils with small areas of compacted bottom.

Іхнофосилії з відкладів бучацької світи (лютецький ярус, еоцен) Луганщини та їхнє палеогеографічне значення

Eleven Fodinichnia, Pascichnia, and Domichnia ichnotaxa (Apectoichnus longissimus (Kelly et Bromley, 1984), cf.Conichnus isp., Gastrochaenolites isp., Gnathichnus isp., Macaronichnus segregatis Clifton et Thompson, 1978,Ophiomorpha nodosa Lundgren, 1891,Palaeophycus isp., cf.Rosselia isp.,Skolithos linearis (Haldeman, 1840),Spongeliomorpha isp., and Thalassinoides isp.) were identified from seven sections of shallow marine sediments of the Buchak Formation (Lutetian, middle Eocene) located in Luhansk Oblast, eastern Ukraine. Traces of bioerosion on the contact surface between the Upper Cretaceous marls and the Buchak Formation indicate the development of the Trypanites Ichnofacies in conditions of high water activity with almost absent sedimentation. Most of the sediments of the Buchak Formation in the study area was formed in the conditions of the Skolithos Ichnofacies, namely in littoral environments with significant water activity, to resist which organisms were forced to build burrow systems. Some time intervals were also characterized by a decrease in the activity of the water, during which the sands of the littoral and probably sublittoral zones were colonized by the trace-makers of Macaronichnus segregatis burrows. In places of mass accumulation of wood, the Teredolites Ichnofacies is recognized, which is characterized by the development of teredenid bivalves specializing in feeding on wood. The contact surface of the Buchak and Kyiv formations is a firmground with the Glossifungites Ichnofacies developed on its surface and under it, which was already functioning during the accumulation of Kyiv Formation sediments. This ichnofacies was characterized by high water activity and the presence of organisms capable of bioturbating relatively dense substrates. The origin of massifs and blocks of quartzite-like sandstones among the sands of the Buchak Formation of Luhansk Oblast and many other sections of eastern and north-eastern Ukraine is not fully understood, but their hydrothermal genesis is most likely. The obtained data are of great importance for the reconstruction of the depositional environment of the middle Eocene sediments in eastern Ukraine.

Marine sponge bioerosion in the forensic taphonomy of terrestrial bone

Bone and teeth, specialised bio-mineralized connective tissues, are left after the typical decomposition process of any vertebrate organism. Their analysis can reveal insights into an organism's life and retrace the history of the remains after death (also known as taphonomy), which ultimately evolves to destruction or fossilization. Studies on the taphonomy of terrestrial mammalian bio-mineralized tissues have mostly focussed on terrestrial depositional environments. Here, samples submerged in the marine environment are investigated.Five archaeological bones of terrestrial mammalian species (pig and oxen) with historically known post-mortem submersion interval (PMSI) (69–316 years) and recovery sites, were analysed macroscopically, microscopically and by microCT. The aim was to characterize for the first time the alterations produced by marine bioeroding sponges, and to discuss their potential interdisciplinary application, with special focus on forensic investigations.The pig samples showed microanatomical preservation (Oxford Histological Index = 3–5), increased total porosity, the presence of old tissue flakes with sponge spicules and traces of bioerosion, such as papillary holes, canals and chambers with microsculptured walls. The presence of such tissue flakes suggested that, at the time of recovery, they may have been free of sediment and inhabited by live sponges. The shape of one internal chamber was identified as the ichnospecies Entobia convoluta as typically produced by shallow, warm-water Cliothosa spp. Surface analyses for further biological evidence remained inconclusive.The taphonomy of skeletal remains has always been relevant in anthropological, natural and forensic studies. In forensics, the role of taphonomy is to contribute to personal identification, cause of death and post-mortem interval (PMI). This study detected the past colonization of terrestrial mammalian bone by marine bioeroding sponges, and aimed to link the taphonomic findings to natural processes and environments. Bioeroding sponges are for the first time confirmed to colonize terrestrial mammalian bone submerged in marine environments, and to promote diagenesis through bioerosion.

Sclerobionts and some representatives of the endobenthos of soft substrates of the Lower Frasnian of the East of the Main Devonian Field

The article considers sclerobionts on the shells of the Frasnian bivalves and brachiopods of the east of the Main Devonian field, as well as common traces of bioerosion of biogenic and abiogenic substrate. In contrast to the averaged data on the Frasnian brachiopod sclerobionts, which demonstrate a clear dominance of auloporids, craniform brachiopods, bryozoas and microconchids, microconchids predominate among Frasnian bivalves sclerobionts and brachiopods of the Main Devonian field and among the eroding sclerobionts — the ichnogenus Arachnostega Bertling. Next in the degree of frequency of occurrence are cornulitids, then auloporids and eroding sclerobionts of the ichnogenus Trypanites Mägdefrau. The ichnogenus Arachnostega Bertling was first identified in the Frasnian rocks of this region. Some Frasnian sclerobionts of the east of the Main Devonian field were inhabitants of a fairly wide range of conditions. For example, microconchida Palaeoconchus omphalodes (Goldf.) are found both on shells burrowing bivalves of inhabitants of soft muddy bottom, and on shells of various representatives of epifauna that lived in conditions of both firmground and hardground. Representatives of three different ethological groups have been identified in cornulitids — fully cemented to the substrate; with a raised anterior part and free-living, attached only at the juvenile stage. The maximum morphological and ethological diversity of cornulitids was recorded on the bivalves of the Main Devonian field from the Dubnik beds corresponding to the maximum of the Frasnian regression. The active development of cornulitids in the Dubnik time was probably favored by the lack of competition with other groups of organisms of similar ethology. A fairly wide range of morphological types of cornulitids isolated within one stratigraphic level indirectly confirms O. Vinn's hypothesis about cornulitids as a group of biological opportunists. The author proved for the first time the presence of two morphologically similar ichnogenera Trypanites Mägdefrau and Palaeosabella Clarke in the Frasnian rocks of the Main Devonian field.

Fossil microbial shark tooth decay documents in situ metabolism of enameloid proteins as nutrition source in deep water environments

Alteration of organic remains during the transition from the bio- to lithosphere is affected strongly by biotic processes of microbes influencing the potential of dead matter to become fossilized or vanish ultimately. If fossilized, bones, cartilage, and tooth dentine often display traces of bioerosion caused by destructive microbes. The causal agents, however, usually remain ambiguous. Here we present a new type of tissue alteration in fossil deep-sea shark teeth with in situ preservation of the responsible organisms embedded in a delicate filmy substance identified as extrapolymeric matter. The invading microorganisms are arranged in nest- or chain-like patterns between fluorapatite bundles of the superficial enameloid. Chemical analysis of the bacteriomorph structures indicates replacement by a phyllosilicate, which enabled in situ preservation. Our results imply that bacteria invaded the hypermineralized tissue for harvesting intra-crystalline bound organic matter, which provided nutrient supply in a nutrient depleted deep-marine environment they inhabited. We document here for the first time in situ bacteria preservation in tooth enameloid, one of the hardest mineralized tissues developed by animals. This unambiguously verifies that microbes also colonize highly mineralized dental capping tissues with only minor organic content when nutrients are scarce as in deep-marine environments.

An assessment of the Arabic RH5 Neolithic fishing community’s mortuary practices by examining human rib cross-sections for bioerosion patterns

The purpose of this research is to offer a micro-anatomical skeletal means for understanding the funeral practices of the Neolithic fishing community of Ra’s al Hamra 5, which is located on the Arabian Peninsula. The archaeological site is located on the Oman gulf of the Arabian Sea coast near the suburb of Qurum; located near the Omani capital Muscat. Archaeological evidence dates the graveyard between 3800 BCE. and 3300 BCE. The burials focused on in this research come from Area 43, a part of the site that held partially burnt and commingled human remains. The study was conducted on 24 histological samples taken from ribs. The traces of bioerosion found on the non-burnt and burnt samples are analyzed. The percentage of bioerosion for each samplehas been documented (area of involvement; Ct.BAD/Ct.Ar.). Less than 5% of the rib cross-sections lack diagenetic alteration. Of the remaining samples, 52.2% show less than 49% diagenetic alteration of the cortical cross-sectional area, while 47.8% of the samples show greater than 50% or more of diagenetic change to the bone matrix. The variability in bioerosion indicates that different lengths of surface decomposition time were involved during funeral practices.This suggests that there may have been a degree of cultural variation employed as these Neolithic people buried their dead. Our results suggest that some of the remains were buried shortly after death. Other remains were exposed to open-air decomposition prior to both burning and burial.

Bioerosion on Late Quaternary Planktonic Foraminifera Related to Paleoproductivity in the Western South Atlantic

AbstractPlanktonic Foraminifera are widely used in paleoceanographic reconstructions, although studies of their trophic interactions are still rare, especially those focusing on predation. Drilling holes are the most frequent traces of bioerosion in foraminifer tests, but environmental factors that control bioerosion are not yet understood. To determine if paleoceanographic variables are associated with bioerosion rates in late Quaternary planktonic foraminifers of the western South Atlantic, geochemical and assemblage analyses were made on a 46 kyr record from a piston core. An age model was constructed based on 10 AMS 14C dates. To reconstruct the paleoproductivity, δ13C, benthic/planktonic foraminifer and the relative abundances of Globigerina bulloides and Globigerinoides ruber (high and low productivity, respectively) were used. Bioeroded tests were counted and found in 21 of the 25 identified species, with frequencies ranging from 8.84% to 16.7%. Bioerosion was different in two groups identified by cluster analysis, with a higher intensity during glacial times, showing a strong correlation with paleoceanographic fluctuations. Paleoproductivity estimates and bioerosion rates show a significant correlation, suggesting that bioerosion is more frequent in eutrophic environments and more inhibited in oligotrophic conditions. However, even with a strong correlation between bioerosion and productivity, there is also a negative correlation with sea surface temperature in the study area. Since conditions that promote higher productivity are accompanied by a decrease in surface temperature, the precise distinction between the influence of both variables is hampered. Further research will allow us to explore the potential of planktonic foraminiferal bioerosion as a tool in paleoceanographic studies.

BIOEROSION ON SPINICAUDATA SHELLS FROM A TRIASSIC FRESHWATER PALEOLAKE, MENDOZA, ARGENTINA

ABSTRACTBioerosion by microorganisms is termed microbioerosion. In aquatic systems, microbioerosion affects various substrates, most commonly relatively soluble ones such as sulfates, phosphates, and carbonates. However, the record of microbioerosion in fossil calcareous organisms in lake environments is limited. In northern Mendoza Province, at the locality Paramillos de Uspallata, Triassic sedimentary rocks outcrop, including the Agua de la Zorra Formation, which was deposited in a deltaic and lacustrine system. This study assesses possible bioerosion by microorganisms on spinicaudata shells from the lacustrine sequence and discusses their preservation potential in lacustrine environments. Spinicaudatans from the Agua de la Zorra Formation were analyzed under a binocular microscope and via scanning electron microscopy. Traces, the product of microbioerosion, preserved as molds, were assigned as Type 1 and 2 and were then compared with those generated by cyanobacteria, bacteria, chlorophyte, and fungi that inhabit fresh and brackish water environments. Microbioerosion occurs post-mortem and enhances dissolution of the spinicaudata shells. This, together with bias in extraction methodologies and sampling, is considered the reason for the rarity of spinicaudatans with traces of bioerosion in the lacustrine record.

Conch structures, soft-tissue imprints and taphonomy of the Middle Ordovician cephalopod Tragoceras falcatum from Estonia

Abstract Tragoceras falcatum (Schlotheim, 1820) is a common, loosely coiled estonioceratid (Tarphycerida, Cephalopoda) occurring in the Kunda Regional Stage (early Darriwilian, Middle Ordovician) of Estonia. Although the species is quite well-known, we document some features for the first time. For example, one specimen from the Harku quarry (Estonia) with a phosphatized replacement shell exhibits growth halts (megastriae) on the body chamber. As they are not preserved in smaller specimens, we suggest that these megastriae formed at the approach of maturity, possibly also reflecting sexual dimorphism and cycles of reproduction (iteroparity?). Additionally, the specimen shows minute soft-tissue imprints (drag bands and pseudosutures). These imprints are comparable to patterns in other cephalopods such as ammonoids, bactritids and other nautiloids, but have not yet been reported from Palaeozoic nautiloids. However, they might have been misinterpreted as oncomyarian muscle attachment scars previously. Lastly, we discuss the taphonomy of the specimen, which was encrusted by multiple bryozoan colonies post-mortem. Furthermore, it shows questionable traces of bioerosion.

Bioerosion and encrustation: Evidences from the Middle ‒ Upper Jurassic of central Saudi Arabia

The Middle ‒ Upper Jurassic hard substrates of central Saudi Arabia displayed considerable signs of bioerosion and encrustations. They include organic (oysters, other bivalves, gastropods, corals and brachiopods) and an inorganic carbonate hardground that marks the boundary between the Middle Jurassic Tuwaiq Mountain Limestone and the Upper Jurassic Hanifa Formation. Traces of bioerosion in organic substrates include seven ichnotaxa produced by bivalves (Gastrochaenolites Leymerie, 1842), polychaete annelids (Trypanites Mägdefrau, 1932; MaeandropolydoraVoigt, 1965 and CaulostrepsisClarke, 1908), sponges (Entobia Bronn, 1837), acrothoracican cirripedes (Rogerella Saint-Seine, 1951), gastropods (Oichnus Bromley, 1981) and probable ?Centrichnus cf. eccentricus. The encrusting epifauna on these substrates consist of several organisms, including oysters, serpulid worms, corals and foraminifera. In contrast, the carbonate hardground was only bioeroded by Gastrochaenolite, Trypanites and Entobia. Epibionts on this hardground include “Liostrea Douvillé, 1904-type” oysters, Nanogyra nana Sowerby, 1822 and serpulids. In general, bioerosion and encrustation are less diversified in hardground than in organic substrates, indicating a long time of exposition of organic substrates with slow to moderate rate of deposition in a restricted marine environment. Both organic and inorganic commuinities are correlated with those of other equatorial, subtropical and temperate equivalents.

Taphonomic analysis and sequence stratigraphy of the Albarracinites beds (lower Bajocian, Iberian range, Spain). An example of shallow condensed section

Abstract Several ammonite fossil assemblages from Sierra de Albarracín (Teruel, Castilian Branch) contain abundant specimens of the Ovale and Laeviuscula zones (lower Bajocian, Middle Jurassic), including microconchs and macroconchs of the characteristic genus Albarracinites. Over 1500 ammonites from the type horizon of the species A. albarraciniensis, in the outcrop of Masada Toyuela, have been studied. Ammonites are commonly preserved as phosphatized, calcareous, concretionary internal moulds (mean size = 50.5 mm) of unflattened shells, partially or completely filled with relatively heterogeneous mudstone to wackestone sediment. Incomplete, fragmented phragmocones with calcitic septa are the dominant remains, generally bearing traces of rounding, incrustation and bioerosion. Taphonomic data, such as the predominant taphonomic populations of type 3, composed of reelaborated, relatively heterogeneous concretionary internal moulds, isolated concretionary body chambers and hollow ammonites, bearing traces of abrasion, bioerosion and encrusting organisms, are indicative of low rate of sedimentation and occasional high rate of sediment accumulation, due to sedimentary winnowing and bypassing interrupted by storm depositional events, in shallow-water marine environments. The exceptional occurrence of taphonic populations of type 2 belonging to Albarracinites and Hebetoxyites, with dominant shells of pre-adults and absence of juveniles, suggests autochthonous biogenic production of shells by indigenous populations of Sub-Mediterranean taxa at the Iberian platform system. In the outcrop of Masada Toyuela, the Albarracinites beds correspond to a condensed section, developed in shallow-water, open-marine, carbonate environments of the External Castilian platform. The sharp, irregular base of beds and the normal grading of reworked elements suggest these carbonate deposits were affected by tractive currents, scouring and redeposition. Limestone beds represent storm-related sedimentary events, whereas the local marly intervals represent background-sedimentation time-intervals of winnowing and bypassing on the seafloor. This condensed section is composed of at least four, decimetric or centimetric, expanded-deposit intervals, stacked and showing an overall thinning upward, which constitute a deepening sequence developed during two biochrons. Taphonomic results also corroborate the development of an incipient-deepening phase, which represents the first episode of a deepening half-cycle of third order, in the Albarracín area within the Castilian platform, during the Ovale and Laeviuscula biochrons (early Bajocian).

Origin and paleoecology of Middle Jurassic hiatus concretions from Poland

Bored and encrusted carbonate concretions, termed hiatus concretions, coming from the Middle Jurassic (Upper Bajocian and Bathonian) siliciclastics of the Polish Jura, south-central Poland, have been subjected to detailed paleoecological investigation for the first time. The concretions possess variable morphology and bear distinct traces of bioerosion and encrustation as a result of exhumation on the sea floor during intervals of low sedimentation and/or erosion. The borings are dominated by Gastrochaenolites and Entobia. Epilithozoans, represented by at least 26 taxa, are dominated by sabellid/serpulid worm tubes and bryozoans, while sponges and corals are minor. No relationship between the concretion size and the number of encrusters has been found, suggesting that concretion size was not the primary factor controlling diversity. Stable isotope analyses and the presence of crustacean scratch marks and Rhizocorallium traces on many of the hiatus concretions indicate that they formed just below the sediment–water interface, within the sulfate reduction zone. Moreover, crustacean activities may have been a prelude to their origin, as shapes of many concretions closely resemble thalassinoidean burrow systems. It is also possible that crustacean activity around the concretions promoted their exhumation by loosening the surrounding soft sediment. The presence of borings and encrusters on different concretion surfaces, as well as truncated borings and a number of abraded epilithozoans, indicate that after the concretions were exhumed they were repeatedly overturned and moved on the sea floor, probably due to episodic storm-related bottom currents in shallow subtidal environment.

Macro-borings on Late Cretaceous oysters of Egypt

The present study investigated traces of bioerosion in parautochthonous associations of oysters from the Upper Cretaceous of Egypt. These traces occurred in great quantity in the exterior surfaces of left valves and more abundantly than occurred in the interior surfaces, as well as in the surfaces of right valves. The most common bioerosion traces were formed pre- and/or post-mortem. The recognised borings appeared as systems of chambers and tunnels that were attributed to the ichnogenera Entobia (traces of clionaid sponges), Maeandropolydora (traces of polychaetes) and Gastrochaenolites (mostly traces of bivalves). Of these, the ichnogenus Entobia represents the most destructive component. The distribution and frequency of the observed borings varied greatly in the shells from one species to another, and sometimes within the same species. Patterns of borings (i. e., size, shape, distribution and frequency) indicated that the studied oyster species were lived in nearshore, shallow, relatively low-energy marine environments with low sedimentation rate and high level of productivity, i.e., optimal conditions for several bioeroders and, hence, pronounced bioerosion. These environmental aspects prevailed during and after the life of these oyster assem- blages before final burial in the Late Cretaceous.

BIOTIC INTERACTIONS RECORDED IN SHELLS OF RECENT RHYNCHONELLIFORM BRACHIOPODS FROM SAN JUAN ISLAND, USA

Biotic interactions between brachiopods and spionid polychaete worms, collected around San Juan Islands (USA), were documented using observations from live-collected individuals and traces of bioerosion found in dead brachiopod shells. Specimens of Terebratalia tranversa (Sowerby), Terebratulina unguicula (Carpenter), Laqueus californianus (Koch), and Hemithiris psittacea (Gmelin) were collected from rocky and muddy substrates, from sites ranging from 14.7–93.3 m in depth. Out of 1,131 specimens, 91 shells showed traces of bioerosion represented by horizontal tubes. Tubes are U-shaped, straight or slightly curved, sometimes branched, with both tube openings communicating externally. On internal surfaces of infested shells, blisters are observed. All brachiopod species yielded tubes, except for H. psittacea. Tubes are significantly more frequent on live specimens, and occur preferentially on larger, ventral valves. This pattern suggests selectivity by the infester rather than a taphonomic bias. Given the mode of life of studied brachiopods (epifaunal, sessile, attached to the substrate, lying on dorsal valve), ventral valves of living specimens should offer the most advantageous location for suspension-feeding infesters. Frequent infestation of brachiopods by parasitic spionids is ecologically and commercially noteworthy because farmed molluscs are also commonly infested by parasitic polychaetes. In addition, brachiopod shells are among the most common marine macroscopic fossils found in the Phanerozoic fossil record. From a paleontological perspective, spionid-infested brachiopod shells may be a prime target for studying parasite-host interactions over evolutionary time scales.

Laminar Micrite Crusts and Associated Foreslope Processes, Red Sea

ABSTRACT Forereef slopes in the Red Sea of Sudan exhibit a uniform biozonation that is independent from the topography of the slopes. Below - 120 m, ledges protrude horizontally from sleep cliffs of barrier reefs and atolls as well as from patches of in situ lithified slope sediment on inclined fringing reef slopes. Free surfaces and cavities within these ledges are partly covered by laminar micrite crusts of 7-20 mm thickness. The ledges are formed by an organic framework of living azooxanthellate corals, bryozoans, serpulids and fossil red algae. They are affected by repeated episodes of boring, infilling, and cementation which obliterate much of the original fabric. Concomitant cementation and boring result in asymmetric cement linings which often show geopetal fabrics. The laminar m crite crusts, however, show no significant traces of bioerosion, which are a typical feature of fossil deep-water stromatolites. Two types of lamination have been observed: 1) vertically stacked, irregular, anastomosing laminate with ragged outlines and little lateral persistence which are often accentuated by iron staining, and 2) 0.5-mm-thick laminae of light-grey micrite, rich in fine bioclasts, showing smooth, thin coatings of dark homogenous micrite, which are weakly fluorescent in ultraviolet light. No algal films are preserved, but micritic tubes 10-30 µm in diameter, often bifurcated, form a dense network on the upper surface of the crusts by overgrowing and binding particles. Associated aragonitic rosettes 30-40 µm in diameter may represent calcified coccoid algae or bacteria. If true, these organisms suggest a formation of the latter type of crust by biogenic processes not related to the photic zone. Fenestral porosity and Frutexites textures are absent. Radiocarbon dates from corals within the ledges provide ages of 10,500 YBP. From the time-related decrease in oxygen isotope ratios (versus PDB) of boring micrite (18O = +3.72), micrite crusts (18O = +1.69), and unlithified mud (18O = +0.47) within the youngest voids of the hard substrates, we conclude that crust formation must have taken place in shallower water when sea level was lower during the Early Holocene rise of sea level.