Trace Fossils with Spreiten from the Late Ediacaran Nama Group, Namibia: Complex Feeding Patterns Five Million Years Before the Precambrian–Cambrian Boundary

2014 ◽  
Vol 88 (2) ◽  
pp. 299-308 ◽  
Author(s):  
Francis A. Macdonald ◽  
Sara B. Pruss ◽  
Justin V. Strauss
Keyword(s):  
Shallow Water ◽  
Feeding Habits ◽  
Bedding Plane ◽  
Trace Fossils ◽  
Trace Fossil ◽  
Outer Tube ◽  
Feeding Patterns ◽  
Large Complex

Here we describe large, complex trace fossils in the late Ediacaran Omkyk Member of the Zaris Formation, Nama Group, southern Namibia. The horizontal trace fossils are preserved on a number of talus blocks from a bedding plane of a cm-thick sandstone lens from a single stratigraphic horizon less than 100 m below an ash bed dated at 547.3 ± 0.7 Ma. The forms consist of overlapping U-shaped spreiten elements with parallel limbs surrounded by an outer tube. Individual U-shaped elements are 0.2 to 1 cm in diameter, the outer tube is less than 3 mm in diameter, and the forms as a whole range from 5 to 30 cm long and 3 to 10 cm wide. The specimens commonly show a change in direction and change in diameter. The morphology of these trace fossils is comparable to backfill structures, particularly specimens of Paleozoic Zoophycos from shallow water environments. Here we interpret these horizontal spreiten-burrows to record the grazing of the trace-maker on or below a textured organic surface. The identification of large late Ediacaran trace fossils is consistent with recent reports of backfilled horizontal burrows below the Precambrian–Cambrian boundary and is suggestive of the appearance of complex feeding habits prior to the Cambrian trace fossil explosion.

scholarly journals Pleistocene golden mole and sand-swimming trace fossils from the Cape coast of South Africa

2021 ◽  
pp. 1-18
Author(s):  
Martin G. Lockley ◽  
Charles W. Helm ◽  
Hayley C. Cawthra ◽  
Jan C. De Vynck ◽  
Michael R. Perrin
Keyword(s):  
South Africa ◽  
Trace Fossils ◽  
Trace Fossil ◽  
South Coast ◽  
Environmental Reconstruction ◽  
Cape Coast ◽  
Southeast Coast ◽  
Show Evidence ◽  
Golden Mole ◽  
Body Fossil

Abstract More than 250 Pleistocene vertebrate trace fossil sites have been identified on the Cape south coast of South Africa in aeolianites and cemented foreshore deposits. These discoveries, representing the epifaunal tracks of animals that moved over these sand substrates, complement traditional body fossil studies, and contribute to palaeo-environmental reconstruction. Not described in detail until now, but also important faunal components, are the infaunal traces of animals that moved within these sandy substrates. Six golden mole burrow trace sites (Family Chrysochloridae) have been identified on the Cape south coast. In addition, three sites, including one on the Cape southeast coast, have been identified that show evidence of sand-swimming, probably by a golden mole with a means of locomotion similar to that of the extant Eremitalpa genus. Such traces have not been described in detail in the global ichnology record, and merit the erection of a new ichnogenus Natatorichnus, with two ichnospecies, N. subarenosa ichnosp. nov and N. sulcatus ichnosp. nov. Care is required in the identification of such traces, and the orientation of the trace fossil surface needs to be determined, to avoid confusion with hatchling turtle tracks. Substantial regional Pleistocene dune environments are inferred from these sand-swimming traces.

scholarly journals Lower Cambrian trace fossils from northern Greenland

1988 ◽  
Vol 137 ◽  
pp. 43-53
Author(s):  
J Bergström ◽  
J.S Peel
Keyword(s):  
Lower Cambrian ◽  
Trace Fossils ◽  
Trace Fossil ◽  
East Greenland ◽  
North West ◽  
North Greenland

Rusophyciform and cruzianaeform trace fossils are described from Lower Cambrian siliciciastic shelf deposits in North-West and North Greenland. Cruziana cf. C. dispar Linnarsson, 1869 is reported from the Dallas Bugt Formation of Inglefield Land while a new ichnospecies, Rusophycus marginatus, occurs in the Buen Formation of Peary Land and in the equivalent Humboldt Formation of Daugaard-Jensen Land. These species show no similarity to the Cruziana sp. previously described from East Greenland. The occurrence of C. cf. C. dispar could indicate some similarity in Cambrian trace fossil 'ichnofaunas' between Greenland and Europe but available material is insufficient to ciarify this relationship.

scholarly journals CHONDRITES-CLADICHNUS ICHNOCOENOSIS FROM THE DEEP-SEA DEPOSITS OF PIERFRANCESCO (CRETACEOUS; ITALY): OXYGEN- OR NUTRIENT-LIMITED?

2022 ◽  
Vol 128 (1) ◽  
Author(s):  
ANDREA BAUCON ◽  
GIROLAMO LO RUSSO ◽  
CARLOS NETO DE CARVALHO ◽  
FABRIZIO FELLETTI
Keyword(s):  
Late Cretaceous ◽  
Deep Sea ◽  
Trace Fossils ◽  
Northern Apennines ◽  
Trace Fossil ◽  
Ecological Succession ◽  
Rhythmic Pattern ◽  
Low Oxygen ◽  
Fossil Assemblage

The Italian Northern Apennines are acknowledged as the place where ichnology was born, but there is comparatively little work about their ichnological record. This study bridges this gap by describing two new ichnosites from the locality of Pierfrancesco, which preserve an abundant, low-disparity trace-fossil assemblage within the Late Cretaceous beds of the M. Cassio Flysch. Results show that lithofacies and ichnotaxa are rhythmically organized. The base of each cycle consists of Megagrapton-bearing calciclastic turbidites, which are overlain by marlstone beds with an abundant, low-disparity assemblage of trace fossils. This includes Chondrites intricatus, C. patulus, C. targionii, C. recurvus and Cladichnus fischeri. The cycle top consists of mudstones with no distinct burrows. The rhythmic pattern of Pierfrancesco reflects a deep-sea ecological succession, in which species and behaviour changed as turbidite-related disturbances altered the seafloor. This study opens the question of whether the Chondrites-Cladichnus ichnocoenosis represents low-oxygen or nutrient-poor settings.

The trace fossil Dactyloidites ottoi (Geinitz, 1849) from the Neogene August Town Formation of south-central Jamaica

1993 ◽  
Vol 67 (6) ◽  
pp. 1070-1074 ◽  
Author(s):  
Ron K. Pickerill ◽  
Stephen K. Donovan ◽  
Harold L. Dixon
Keyword(s):  
Detailed Analysis ◽  
Trace Fossils ◽  
Trace Fossil ◽  
Marine Environments ◽  
Biogenic Origin ◽  
South Central ◽  
Rock Record ◽  
Distinctive Morphology ◽  
Detailed Interpretation ◽  
Deposit Feeding

Rosette-shaped problematica are relatively common structures in the Phanerozoic rock record. Historically, they have been accorded a variety of names and documented from various shallow to deep marine environments. Unfortunately, the detailed interpretation of many such structures as biogenic (trace fossils, medusoids, or other body fossils; see, for example, Häntzschel, 1970, 1975) or nonbiogenic (for example, Pickerill and Harris, 1979) in origin still remains to be resolved. However, a detailed analysis of one such structure by Fürsich and Bromley (1985), namely Dactyloidites Hall, 1886, convincingly demonstrated its biogenic origin. The distinctive morphology of Dactyloidites and its synonyms was interpreted by Fürsich and Bromley (1985) to result from successive probings of an essentially stationary deposit-feeding, worm-like organism, possibly possessing a proboscis, to produce a rosetted, vertical spreiten with a centrally located, vertical or subvertical shaft.

Martian stick-like structures are not trace fossils: a new protocol for testing ichnogenicity synthesized from paleosol ichnology

2021 ◽  
pp. 1-8
Author(s):  
Jorge F. Genise
Keyword(s):  
Surface Morphology ◽  
Trace Fossils ◽  
Trace Fossil ◽  
The Future ◽  
Study Case ◽  
First Time

Abstract There are different criteria that are usually analysed independently before identifying a new trace fossil, such as morphological regularity, completeness, dispersion, recurrence and complexity, surface morphology, and context. The synthesis of these criteria, as utilized in paleosol ichnology, composes a protocol that is presented herein for the first time and can be used for testing the ichnogenicity of trace-like structures in any paleoenvironment of Earth or Mars. As a study case, the Martian ‘stick-like structures’ do not fulfil any of the requirements posed by this protocol to be postulated as trace fossils. The ichnogenicity test, focussed exclusively on morphology and context, is simpler but equally useful as the biogenicity ones. It may be applied in the future with other potential cases before carrying on more complex analyses or to evaluate the astrobiological interest of trace-like structures.

Trace fossils and tropical karst

2016 ◽  
Vol 154 (1) ◽  
pp. 166-168 ◽  
Author(s):  
STEPHEN K. DONOVAN
Keyword(s):  
Trace Fossils ◽  
Trace Fossil ◽  
The Tropics ◽  
Growth Deformity ◽  
Tropical Karst

AbstractTwo crinoid pluricolumnals from Permian rocks of Timor show similar patterns of external pitting. Platycrinitid sp. preserves circular, parabolic pits that do not cross-cut between columnals, some have raised rims and at least one columnal shows a growth deformity. These pits are interpreted as the trace fossil Oichnus paraboloides Bromley. Crinoid sp. indet. has particularly dense pits cross-cutting columnals on one side of the pluricolumnal only and extending onto the contiguous limestone; it is a Holocene microkarstic solution feature. Care must be taken to separate true bioerosive trace fossils from modern microkarstic features in limestones in the tropics.

Trace fossils from the Lower Muschelkalk of Raciborowice Górne (North Sudetic Synclinorium, SW Poland) and their palaeoenvironmental interpretation

2013 ◽  
Vol 63 (3) ◽  
pp. 315-353n ◽  
Author(s):  
Alina Chrząstek
Keyword(s):  
Trace Fossils ◽  
Carbonate Ramp ◽  
Trace Fossil ◽  
Germanic Basin ◽  
Sw Poland ◽  
Bathymetric Changes ◽  
Lower Muschelkalk ◽  
Short Episode

Abstract The following trace fossils have been recognised in the Lower Muschelkalk of Raciborowice Gorne (North Sudetic Synclinorium, SW Poland): Archaeonassa fossulata, Balanoglossites triadicus, ?Gastrochaenolites isp., Lockeia isp., Palaeophycus tubularis, Palaeophycus isp., ?Planolites beverleyensis, P. montanus, Planolites isp., ?Protovirgularia isp., Rhizocorallium commune var. auriforme, R. commune var. irregulare, R. jenense, Skolithos linearis, Thalassinoides suevicus and Trypanites weisei. Coprolites and an unidentified trace fossil A are also described. The trace fossils allow the discrimination of five ichnoassociations in the Raciborowice Gorne section: (IA 1) Rhizocorallium- Pholeus, (IA 2) Rhizocorallium-Palaeophycus, (IA 3) Thalassinoides, (IA 4) Trypanites-Balanoglossites and (IA 5) Planolites-Palaeophycus. The Lower Muschelkalk succession was deposited on a shallow carbonate ramp affected by frequent storms. Deposition commenced with sedimentation in a restricted lagoon on the inner ramp with a short episode of sabkha formation. It continued on the middle and outer ramp and then on a skeletal shoal of the outer ramp and in an open basin. Ichnoassociation IA 5 is related to a maximum transgression that commenced with the deposition of the Spiriferina Bed and which probably marked the opening of the Silesian-Moravian Gate. The basin underwent two shallowing episodes, as evidenced by ichnoassociations IA 3-IA 4, resulting in the formation of hardgrounds. Bathymetric changes in the Raciborowice Gorne section correspond well with a general transgressive trend in the Germanic Basin.

New ichnofabrics of the Cenomanian–Danian Chalk Group

2020 ◽  
Vol 90 (7) ◽  
pp. 701-712
Author(s):  
Kasper H. Blinkenberg ◽  
Bodil W. Lauridsen ◽  
Dirk Knaust ◽  
Lars Stemmerik
Keyword(s):  
Trace Fossils ◽  
Trace Fossil ◽  
Shelf Area ◽  
Fine Grained ◽  
Fossil Assemblages ◽  
Facies Types ◽  
Body Fossil ◽  
Substrate Hardness ◽  
Nw Europe ◽  
Different Levels

ABSTRACT The Cenomanian–Danian Chalk Group of NW Europe is characterized by distinct trace-fossil assemblages dominated by Thalassinoides isp., Planolites isp., Zoophycos isp., and Chondrites isp., whereas ichnogenera such as Taenidium and Phycosiphon are rare. The trace fossils form a complex tiering arrangement, which reflects burrowing activities of diverse benthic associations that operate at different levels in the sediment column, dynamic sedimentation rates, and changes in substrate hardness during progressive burial, forming intricate ichnofabrics. In the Danish Basin, studies of chalk ichnofabrics have focused mainly on the Maastrichtian. Studies of the shallower, grain-rich Danian chalk have revealed similar trace-fossil assemblages, whereas the ichnology of the fine-grained, deeper-water Danian deposits is poorly known. Based on detailed facies and ichnofabric analysis of a mid-Danian silica-rich, pelagic chalk located in the central, deeper shelf area of the Danish Basin, four facies types, eight ichnotaxa, and two ichnofabrics are recognized. Most conspicuous and abundant are randomly distributed, variously sized meniscate burrows attributed to Bichordites isp. and Taenidium isp., whereas other common chalk trace fossils are rare or absent. This trace-fossil assemblage outlines two new ichnofabrics in the NW European chalk, which are dominated principally by upper-tier traces. The producer of the abundant Bichordites isp. and Taenidium isp. burrows is identified as a sea urchin on the basis of an exceptionally preserved Bichordites isp. trace aligned with an irregular echinoid body fossil. The identified ichnofabrics controlled early silicification and produced a more complex distribution of silica concretions compared with chalk successions elsewhere. This results in volumetrically thick silica concretion-rich units rather than distinctive silica bands as seen in other Upper Cretaceous and Danian chalk units.

Devonian depositional environments in the Darwin Mountains: Marine or non-marine?

1993 ◽  
Vol 5 (2) ◽  
pp. 211-220 ◽  
Author(s):  
Ken J. Woolfe
Keyword(s):  
Fresh Water ◽  
Depositional Environment ◽  
Trace Fossils ◽  
Depositional Environments ◽  
Trace Fossil ◽  
Glacier Area ◽  
Red Beds ◽  
Fossil Assemblage ◽  
Considerable Debate

The depositional environment of the Devonian Taylor Group has been subject to considerable debate for over 30 years. The debate stems largely from a belief that the abundant and diverse trace fossils represent a marine ichnofauna, whereas sedimentary features, including palaeosols, desiccation polygons and red beds, are more typical of a non-marine setting. The debate is reconciled by a reinterpretation of the trace fossil assemblage which shows that the trace fossils comprise a typical fresh water (Scoyenia ichnofacies) assemblage, and their occurrence in the Taylor Group in the Darwin Glacier area is entirely consistent with deposition in a mixed fluvial-lacustrine-subaerial environment.

New occurrences of Oldhamia and other trace fossils in the Cambrian of the Yukon and Ellesmere Island, arctic Canada

1994 ◽  
Vol 31 (5) ◽  
pp. 767-782 ◽  
Author(s):  
H. J. Hofmann ◽  
M. P. Cecile ◽  
L. S. Lane
Keyword(s):  
North America ◽  
Western Europe ◽  
Trace Fossils ◽  
Trace Fossil ◽  
Ellesmere Island ◽  
Early Cambrian ◽  
Arctic Canada ◽  
North Central ◽  
Middle Cambrian ◽  
New Occurrences

Trace fossil assemblages from green and maroon argillites at 34 localities in the British Mountains and Barn Mountains of northernmost Yukon, and 3 localities in the Grant Land Formation of northern Ellesmere Island contain abundant Planolites spp., Oldhamia curvata, Oldhamia flabellata, and Oldhamia radiata, and rare Oldhamia antiqua, Oldhamia? wattsi (n.comb.), Bergaueria hemispherica, Cochlichnus sp., Didymaulichnus? sp., Helminthoidichnites sp., Monomorphichnus sp., Protopaleodictyon sp., and Tuberculichnus? sp. Additionally, 11 new sites in the Selwyn Mountains of north-central Yukon have yielded an ichnofauna including Helminthorhaphe sp., O. curvata, O. flabellata, O. radiata, Plagiogmus? sp., Planolites spp., and unidentified small hemispherical traces. All these assemblages are interpreted as Early Cambrian to early Middle Cambrian, based on comparison with Oldhamia-bearing ichnofaunas of similar age in North America, Argentina, and western Europe, and on archaeocyathids and olenellids in overlying units.

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