Ichnospecies Research Articles

A new etching trace from the Savignone Conglomerate (Oligocene), NW Italy, probably produced by limpet gastropods

A new ichnogenus and ichnospecies ( Solealites ovalis ) of etching trace is preserved on the surfaces of clasts from the Savignone Conglomerate (Oligocene) in the Palaeogene Piemonte Basin in NW Italy. It is a shallow, oval depression with a central elevation, which was produced probably by limpet gastropods and served as their home scar, but other gastropods or even sea anemones are not excluded as the trace makers. The conglomerate is interpreted as a deposit of a fan delta, whose clasts have been bioeroded in an intertidal and shallow subtidal shore zone and redeposited to the deeper sea.

NEW RECORDS AND ICHNOSPECIES OF LINEAR LEAF MINES FROM THE LATE MIOCENE-PLIOCENE FROM ARGENTINA AND THE ESTABLISHMENT OF LEAF-MINING ICHNOTAXOBASES

The ichnospecies Cuniculonomus parallelus Givulescu 1984 and Stigmellites serpentina Kozlov 1988 are recorded for the first time in Argentina and the new ichnospecies Cuniculonomus saltensis isp. nov., Stigmellites vitatus isp. nov. and Stigmellites pervenae isp. nov are defined from two Miocene localities: Penas Blancas and Quebrada del Horno, from northwestern Argentina. A set of characters to identify fossil linear mines is provided as well as five ichnotaxobases to differentiate the ichnogenera Cuniculonomus , Stigmellites and Phytomyzites. Two ichnospecies are now revised and included in Phytomyzites: P. arcuata (Krassilov 2008a) comb. nov. ( Ophionoma ) and P. crucitracta (Krassilov 2008a) comb. nov. ( Troponoma ). Finally, a review of fossil record of linear mines is provided.

LOWER PALEOGENE COMPLEX ANT NESTS FROM ARGENTINA: EVIDENCE FOR EARLY POLYDOMY IN ANTS?

Fil: Genise, Jorge Fernando. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales Bernardino Rivadavia; Argentina

TAPHONOMIC ASPECTS OF THE RADIAL BACKFILL OF ASTEROSOMIDS IN OLIGO-MIOCENE TURBIDITES OF CENTRAL ITALY (NORTHERN APENNINES)

One hundred asterosomid specimens from 24 sections of several flysch facies of the Northern (Tuscan-Romagna-Umbrian) Apennines have been analysed to study their radial backfill using taphonomic characteristics. These characteristics include the stratinomic position in the bed, the shape and morphology of concave or convex tunnels, the type of subhorizontal crossing, the disposition and shape of wrinkles and cracks, and newly recognized fan-shaped, micro-debris flow deposits in the sides of tunnels induced by the radial backfilling compression causing shock in mud. Many types of preservation have been found in Halopoa ichnospecies while other preservational aspects ( Asterosoma and Lennea in primis, while the Fucusopsis preservation and aspect has been included in ichnogenus Halopoa ). This comparative taphonomic study enhances, for the first time in the turbidites of Apennines, the role of radial backfill as a type of deposit-feeding in deep-sea firmgrounds and softgrounds, produced by soft-bodied organisms (probably worms).

On the doctrine of ichnotaxonomic conservatism: the differences between ichnotaxa and biotaxa

On the doctrine of ichnotaxonomic conservatism: the differences between ichnotaxa and biotaxa

TAXONOMIC REVIEW OF CHONDRITES AFFINIS (STERNBERG, 1833) FROM CRETACEOUS-NEOGENE OFFSHORE-DEEP-SEA TETHYAN SEDIMENTS AND RECOMMENDATION FOR ITS FURTHER USE

The branched trace fossil Chondrites affinis (Sternberg, 1833), synonymised so far with C. targionii (Brongniart, 1828), has been analyzed in an exceptionally well preserved specimen from the Saraceno Formation (?Upper Cretaceous; ?Eocene-Miocene) in the southern Italy, its holotype (Prague Museum), and in other materials. It appeared that C. affinis displays a smaller burrow system/burrow width ratio and a larger size (burrow width typically over 4 mm and burrow system width over 150 mm) than C. targionii , without continuity of the latter parameters between these ichnospecies. Therefore, Chondrites affinis is considered as a separate ichnospecies, and is recommended for further use. It occurs in Upper Cretaceous to Neogene offshore, deep-sea, mostly marly sediments, and its unquestionable occurrences are known so far from the European Alpides.

IV International Workshop on Ichnotaxonomy, June 21–26

The 4th International Workshop on Ichnotaxon� omy took place June 21–26, 2010 at the Geological Institute RAS, Moscow, Russia. Investigation of trace fossils is a branch of sedimentary geology that is devel� oping vigorously at present. The study of ichnofossils is of theoretical and practical value to paleontology, paleoecology, paleogeography, sedimentology, stratig� raphy, facies and basin analysis. The results of pale� oichnology are frequently applicable to sequence stratigraphy and for prospecting for hydrocarbon pools. The active development of this branch of sci� ence during the last 10–15 years is evident from the regular organization of workshops on key problems of paleoichnological research. In particular, these have covered bioerosion, ichnofacies, ichnotextures, and ichnotaxonomy. Due to the specific character of the research objects, their correct diagnosis, description, and nomenclature is a significant problem in pale� oichnology.

MORPHOLOGIC VARIATIONS OF THE TRACE FOSSIL RUTICHNUS IN CM-THICK TURBIDITES FROM THE VERGHERETO FORMATION (NORTHERN APENNINES, ITALY)

The analysis of 56 specimens of the branched, walled post-depositional trace fossil Rutichnus , sampled from 31 thin-bedded, overbank turbidites from the Verghereto Formation, Romagna Apennines, indicates high morphologic variability of this ichnotaxon in hypichnial preservation. The variability concerns the arrangement of outer and inner walls, number and shape of annulations, distribution of pustules, the (false) branching arrangement and the general external shape. Highest variability has been observed mainly in the Rutichnus rutis ichnospecies, clearly less in the R. irregularis ichnospecies that is rare. The Dino-Lite microscope camera analysis of oriented thin sections indicates that endichnial preservation exhibits many structures due to burrowing in soft substrate, destroying laminae of sand. Consequently Rutichnus probably was produced by a worm or arthropod, inducing strong deformation in turbidite sand during the feeding activity on phytodetritus and organic matter transported by the turbidity flow.

BORING SPONGES (ICHNOGENUS ENTOBIA ) IN MESOZOIC LITHOCODIUM CALCIMICROBIAL CRUSTS

Globular cavities in calcimicrobial Lithocodium crusts are interpreted as trace fossils of boring sponges belonging to the ichnogenus Entobia . Two informal groups can be differentiated: a Norian-Rhaetian group from Tabas area(NE Iran) and Adnet (near Salzburg, Austria), characterized by large chambers and broad bifurcating apertural canals, and a second group from the Aptian of central Italy presenting smaller chambers and canals. The distal ends of these canals are closed by alveolar structures, preventing water circulation and leading to the death of the sponge.

TAPHONOMIC ASPECTS OF THE MIOCENE ICHNOFOSSIL-LAGERSTÄTTE FROM CALCARENITE TURBIDITIC BEDS IN THE VERGHERETO MARLS (NORTHERN APENNINES, ITALY)

Five, 3-8 cm-thick calcarenitic turbiditic beds belonging to overbank deposits in the marginal sector of Marnoso-arenacea Basin, close to the intrabasinal high of Verghereto (Romagna, Northern Apennines, Upper Miocene), exhibit a well preserved ichnofossil-lagerstatte. The lagerstatte is composed by 43 ichnotaxa: 31 of them are preserved as casts at the sole of turbidites (background hypichnia) (group a), while 12 of them occur at the top (post-turbidite epichnia) and within (endichnia) (group b). The ichnodensity reaches its maximum at the top of the turbiditic beds. Background hypichnia (group a) is represented by graphoglyptids and non-graphoglyptid resting traces (background ichnofauna), with three-dimensional networks and shafts, meander systems, radiate, plug-shaped or stellatae structures forming clusters and unbranched systems of strings. Many taphonomic features suggest a fluting induced by bottom currents; graphoglyptids should have colonised the substrate after the action of these currents being not destroyed or fluted. All hypichnial structures are perfectly preserved by the turbidite casting and in this phase also endichnial burrows could develop. Post-turbidite epichnia (group b) concern vagile feeding burrows that developed horizontal patterns in a post-turbiditic regime, during the suspension phase of fine material; they were probably produced by organisms transported by suspension flows. Here, the very high ichnodensity suggests a competition among burrowers under stable currents with occurrence of vagile opportunistic organisms immediately followed by others that produced radiate spreite structures. SHORT NOTE

A THEROPOD DOMINATED ICHNOCOENOSIS FROM LATE HAUTERIVIAN-EARLYBARREMIAN OF BORGO CELANO (GARGANO PROMONTORY, APULIA, SOUTHERN ITALY)

Several dinosaur footprints were discovered on three different levels cropping out in the CO.L.MAR quarry, south of the village of Borgo Celano in the Gargano Promontory (Apulia, southern Italy). The track-bearing levels belong to a carbonate inner platform succession referred to the Lower Cretaceous (upper Hauterivian-lower Barremian). This paper describes only the lowest dinoturbated bed, where footprints are preserved as natural cast. Forty footprints, mostly tridactyl, have been attributed to medium-sized theropods. Tridactyl tracks are similar to Kayentapus Welles, 1971 regarding ichnotaxonomy. Round shaped footprints, previously not described from this site, are found in association with tridactyl footprints and are related to ornitischian dinosaurs.

THE ICHNOFOSSIL GENUS PARADICTYODORA OLIVERO, BUATOIS & SCASSO(2004) FROM THE PLIOCENE OF THE NORTHERN APENNINES, ITALY

The ichnospecies Paradictyodora flabelliformis (Di¦Alessandro & Fursich) is reported for the first time from the Pliocene i§Argille Azzurre Formationi¨ of Northern Italy. The horizon has an older age and is deeper than the shallow-water protected shoreface environment where the type specimens have been found. A narrow tubular structure exceptionally preserved on the specimen studied possibly supports the tellinid bivalve model instead of the Arenicola model for the origin of the trace fossil.

Notostraca trackways in Permian playa environments of the Lodève basin (France)

For nearly 20 years, Dr. Lapeyrie, surgeon at Lodeve, has gathered many fossils coming from the Salagou Formation of the Lodeve Permian basin. They are Insects, Notostraca, plants and ichnofossils. Among the latter, appears a multitude of Arthropoda trackways, finely preserved, which were collected in the top of sequences deposited in a playa environment. The locomotion experiments undertaken with extant animals suggested allocation of the majority of these trackways to Notostraca which are also known by several hundreds of remains (carapace, appendages, body whole). From these different parts, it was described as Triops cancriformis permiensis and Lepidurus occitaniacus. All these trackways were made under water and correspond to various etho-morphotypes known in the literature under the name of Acripes for the walking prints, Rusophycus for resting traces (= stationary digging; horizontal, procline and opisthocline positions) and Cruziana for locomotion active and digging. Many fossiliferous slabs clearly allow to see the passage from one activity to another. A similar situation was also filmed with the modern Lepidurus. The following ichnotaxa were distinguished: Acripes multiformis nov. isp, Rusophycus eutendorfensis, R. carbonarius, R. versans, R. minutus, R. furcosus, Cruziana problematica, C. pascens and Scoyenia, isp., less common. With also numerous footprints, this assemblage characterizes the Scoyenia facies restricted to overbank settings. For the Salagou Formation, they correspond to a floodplain/playa in which shallow and temporary pools were inhabited by Nostotraca, Insects, Arachnids and Conchostraca (= Spinicaudata + Laevicaudata), this last group only known by body-fossils. This distal playa environment under arid climate lasted during most of the Permian, possibly between Upper Cisuralian to lower Lopingian.

BIOEROSION SCARS OF ACORN BARNACLES FROM THE SOUTHWESTERN IBERIAN PENINSULA, UPPER NEOGENE

New etching trace fossils produced by the attachment of balanid barnacles on fossil molluscs, mainly bivalves, from the Upper Miocene of Cacela (southern Portugal) and Lower Pliocene of Huelva (southwestern Spain) are described. These traces are named as Anellusichnus igen. n. due to the ring-like shape of the scars. Two ichnospecies are recognized: A. circularis n. isp., consisting in a circular scar defined by a discoloured area or by a circular to subcircular trench and A. undulatus n. isp. that has a sinuous perimeter reflecting the undulate pathway of the furrow and a flat shelf etched into the substrate. Within the outer furrow both can display a cluster of circular, oval or subpolygonal concentric lines. A. undulatus n. isp. shows several morphologies that correspond to different ontogenetic stages. SHORT NOTE

ICHNOTAXONOMY AND ETHOLOGY OF BORINGS IN SHALLOW-MARINE BENTHIC FORAMINIFERS FROM THE MAASTRICHTIAN AND EOCENEOF NORTHWESTERN AND SOUTHWESTERN TURKEY

Larger benthic foraminiferal tests from the Maastrichtian and Eocene of western Turkey contain a large variety of borings. Two ichnospecies are defined. Maeandropolydora osmaneliensis isp. nov. in tests of Orbitoides is distinguished by a tube, winding sinuously in an irregular manner. This boring was formed by a foraging parasite or scavenger, where the tracemaker specifically exploited certain parts of its substrate. Trypanites helicus isp. nov. in tests of Nummulites is characterized by its tube coiled into a spiral. The boring is interpreted as a dwelling trace. As the boring may be considered to have both idiomorphic and stenomorphic features, it represents an ethological and taxonomic dilemma. To avoid inherent subjectivity within taxonomic classifications, we suggest the exclusion of ethological interpretations from diagnoses. The occurrence of borings may affect the preservational potential of the foraminiferal tests, and thus on the outcome of palaeoenvironmental analyses.

Trace Fossils In The Western Fan Of The Cingöz Formation In The Northern Adana Basin (Southern Turkey)

In this study, the trace fossils in the Lower-Middle Miocene turbiditic Cingoz formation cropping out around the Karaisali - Catalan - Egner regions have been examined for the first time. The trace fossils occur in a sequence, identified as submarine fan deposits. Based on their morphological characteristics, nineteen trace fos- sils have been identified; eleven of them are ichnospecies and eighteen ichnogenus.

Devonian ichnofossils and their environmental significance of northern belt of Western Qinling Mountains

It is beheved that the Shujiaba Formation belongs to a series of thick turbidites. 20 ichnogenera have been found in the formation, of which 14 genera were found in the Devonian System of China for the first time The ichnogenera are mostly of typical deep-water ones and belong to the Nereites ichnofacies A detailed study of morphology and behaviour of the trace fossils indicates that the Shujiaba Formation was deposited in a bathyal-abyssal environment.

Ichnological study of shallow marine endolithic sponges from the Italian coast

Living boring sponges belonging to eight species of the genera Siphonodictyon , Cliona and Cliothosa , were collected from the limestone seafloor of the Apulian coast. Samples were taken in zero to -20 m water depth. Spicule preparations from the sponges, and epoxy casts of the borings, facilitated a comparison of the animal and its work. The borings were analyzed ichnotaxonomically and attributed to 11 ichnospecies of Entobia . Direct correlation between biospecies and ichnospecies was not found in all cases. Several ichnospecies are new, and some of these are named using Pleistocene material. The new ichnospecies are Entobia gigante a, E. magma and E. parva .

The Silurian-Devonian disconformity in southern Ontario

ABSTRACT The sub-Devonian (Gedinnian) disconformity in southern Ontario is developed upon the Upper Silurian Bertie Formation. Two erosion surfaces are recognizable: pre- and post-Oriskany sandstone. An extensive system of Silurian joints and fractures is developed within the Bertie beds. A few of these are filled with Oriskany-type orthoquartzitic sand and conglomerate, and represent subaerial solution prior to Oriskany deposition. The others are filled with Springvale sand and conglomerate and represent solution and widening during subaerial exposure following Oriskany deposition. Below the disconformity surface, a system of solution vugs and extensive leached patches stained with hydrocarbons is present in the uppermost Bertie dolomite. The vugs and leached patches are vadose and represent extensive freshwater solution during subaerial exposure. The mottling is not developed below the disconformity beneath the Oriskany, which suggests that leaching and vug porosity developed only during the second erosional period. The disconformity surface consists of a solution topography of rounded ridges, solution pits and other small-scale karren forms. Straight to gently curved borings of the morphological ichnogenus Trypanites are present on the disconformity surface and were established during the marine transgressions. The walls of the Trypanites borings are penetrated by silica-infilled algal microborings. No evidence for the presence of an encrusting epizoan fauna was found. Rounded solution pitting developed on the surface may be the result of an algal or moss cover. Dendritic, branching and single linear etchings developed on some parts of the disconformity greatly resemble the etchings produced by land-plant root or rhizome systems. Analysis of sedimentological and paleontological data leads to the recognition of a marine transgressive-regressive sequence in which two distinct subaerial disconformities are present.