Arachnostega (trace fossil) on a cyclidan (Crustacea) carapace from the Pennsylvanian of Ohio, USA

Trace fossils and the Cambrian explosion

Lithofacies distribution of invertebrate and vertebrate trace-fossil assemblages in an Early Mesozoic ephemeral fluvio-lacustrine system from Argentina: Implications for the Scoyenia ichnofacies

Discriminating ecological and evolutionary controls during the Ediacaran–Cambrian transition: Trace fossils from the Soltanieh Formation of northern Iran

The increase in trace fossil diversity across the Neoproterozoic-Cambrian boundary often is presented in terms of tabulations of ichnogenera. However, a clearer picture of the increase in diversity and complexity can be reached by combining trace fossils into broad groups defined both on morphology and interpretation. This also focuses attention on looking for similarites between Neoproterozoic and Cambrian trace fossils. Siliciclastic sediments of the Neoproterozoic preserve elongate tubular organisms and structures of probable algal origin, many of which are very similar to trace fossils. Such enigmatic structures include Palaeopascichnus and Yelovichnus, previously thought to be trace fossils in the form of tight meanders.A preliminary two or tripartite terminal Neoproterozoic trace fossil zonation can be be recognized. Possibly the earliest trace fossils are short unbranched forms, probably younger than about 560 Ma. Typical Neoproterozoic trace fossils are unbranched and essentially horizontal forms found associated with diverse assemblages of Ediacaran organisms. In sections younger than about 550 Ma a modest increase in trace fossil diversity occurs, including the appearance of rare three-dimensional burrow systems (treptichnids), and traces with a three-lobed lower surfaces.

Chapter 34 - Trace Fossils in an Archaeological Context: Examples from Bison Skeletons, Texas, USA

In recent years trace fossils have been studied in carbonate and siliceous rocks. Shales have largely been ignored. This study describes trace fossils from the anoxic Upper Devonian black shale in east-central End_Page 729------------------------------ Kentucky along the western margin of the Appalachian basin. Trace fossils occur where dolomite overlies black shale in the lower part of the Huron Member (basal New Albany or Ohio Shale). Cruziana, Zoophycos, Planolites, Phycodes, Chondrites (Type A), Trichichnus, Teichichnus, Laevicyclus, and a newly described large burrow form are common. Up section, trace fossils are found where gray shale overlies black shale in the upper lower part of the Huron Member (Teichichnus, Planolites, Chondrites-Type B, Rhizocorallium, and Zoophycos) and the Three Lick Bed (Chondrites-Types C and D, Planolites-like burrows, Zoophycos, and pyritic burrows). A combination of interpretations based on the stratigraphy, lithology sedimentary structures, and trace fossils suggests that the Devonian black shale was deposited in an upward-deepening sequence transgressive over the axis of the present Cincinnati arch in east-central Kentucky. The carbonate environment of the underlying Middle Devonian Boyle dolomite contains trace fossils and features suggestive of shallow water. At the beginning of the Upper Devonian, migration of black muds onto the platform rimming the Cincinnati arch allowed interbedding with the carbonates. Up section, the carbonate-black shale environment was replaced by entirely black shale deposition. Periodic oxygenation allowed brief periods of burrowing. Trace fossil correlation will be helpful in understanding the detailed stratigraphy within the mid-continent Upper Devonian black shale. End_of_Article - Last_Page 730------------

Over the years, we've participated in several different workshops and short courses on trace fossils. So why this one? Our intention in bringing together these papers for the Trace Fossil Short Course is to give an overview of how trace fossils can be used in paleontology. Historically, trace fossil research has centered on paleoenvironmental and depositional reconstructions—areas where trace fossils have much to tell. Indeed, the use of trace fossils by sedimentologists has flourished and is experiencing another burst of activity through the use of ichnofabrics in sequence stratigraphic studies. But trace fossils have paleontological stories to tell as well. Their use in uncovering the first occurrences of life in different parts of the stratigraphic column is well documented (e.g., the classic example of trace fossils occurring before body fossils in Precambrian/Cambrian transitional strata) as is their use in detailing different morphological details of unpreserved taxa or body parts.

Trace fossils of Ordovician radiolarian chert and siliceous mudstone in Newfoundland, Canada

In the past an ‘explosion’ in diversity and abundance of small shelly fossils and of trace fossils has served to mark the base of the Cambrian. However, no evidence has been presented to prove that the ‘explosions’ of the two groups were synchronous. We describe small shelly fossils and trace fossils from the same phosphatic limestone beds that indicate that the two events were separate in time. The small shelly fossils are Anabarites trisulcatus, Hyolithellus cf. H. isiticus, Microcornus? sp., Protohertzina anabarica, P. unguliformis, P. sp. A, Pseudorthotheca sp. A, Rushtonia? sp. A, four types of tuberculate plates and one type of reticulate plate. These fossils represent a restricted, ‘pre-explosion’ fauna and are assigned to the Anabarites-Circotheca-Protohertzina Assemblage Zone, an uppermost Precambrian zone in the Meishucun Stage, Yunnan Province, China. A point at the top of this zone has received strong international endorsement for future designation as the base of the Cambrian. Associated with the small shelly fossils are the trace fossils Cruziana sp. A, Cruziana? sp. B, Rusophycus sp. A, Palaeophycus rubdark and arthropod scratch marks. If found in isolation, this trace fossil assemblage would be considered as post-Precambrian because it includes large, highly organized arthropod traces that are traditionally accepted as occurring above the trace fossil ‘explosion’. We therefore conclude that the trace fossil ‘explosion’ predates the small shelly fossil ‘explosion’. If the proposed location of the base of the Cambrian in Yunnan is accepted, the small shelly fossil ‘explosion’ concept and its relationship to the boundary would not be greatly modified. The trace fossil ‘explosion’, however, would no longer indicate the base of the Cambrian and the ranges of some trace fossils would be extended into the Precambrian.

Trace fossils from Carboniferous floodplain deposits in western Argentina: implications for ichnofacies models of continental environments

Chapter 8 - The Application of Trace Fossils to Biostratigraphy

This report documents the discovery of repichnia trace fossils Ptychoplasma (P. excelsum and P. vagans) and Dendroidichnites (D. irregulare); the fodichnia traces ?Ctenopholeus (?C. kutcheri) and cubichnia traces Bergaueria (B. hemishperica) from silty limestones of the Cretaceous Bagh Formation. These trace fossils have significant implications for the depositional facies and the paleo-environmental interpretations of the Bagh Formation, which have long been debated. Previously identified traces of Protovirgularia were also found in association with the newly discovered trace fossils, indicating the coexistence of both wedge and cleft-foot bivalves. The western area of the mainland Gujarat is known for its abundance and diversity of trace fossils. The trace fossil bearing Cretaceous rocks in the region occur as thin irregular detached patches and linear outcrops. Previous studies documenting trace fossil assemblages from the Bagh Formation characterised them as a combination of dwelling, feeding and locomotion forms, with the stratigraphic unit becoming less fossiliferous westward. Trace fossils in this formation have been studied and described by many workers in the surrounding areas; however, ichnofossils described in this study are new to the Bagh Formation in this area. These trace fossils were observed on recently exposed outcrops along road cuts associated with new road construction from Khasra to Mogra village around Kadipani in Mainland Gujarat.

The Sácaras Formation (Albian, Lower Cretaceous) of the Serra Gelada succession (Prebetic of Alicante), southeast Spain, comprises carbonate-rich, upwards thickening parasequences in which many types of trace fossils have been identified. The present study focuses on two types of tubular trace fossil characterized by features of their external coating. The first type is represented by a shell-covered, structured trace fossil, up to 4?cm in diameter and 40?cm in length, built horizontally, from rectilinear (type 1) to gently curved (type 2), which envelopes an unstructured pipe of grey silty sediment. The coating is characterized by imbricated, flat particles, mainly orbitolinid foraminifers and other planar bioclasts, forming thin concentric layers; in cross section the bioclasts produce a typical plumed structure. This trace fossil represents a new ichnogenus and ichnospecies, here named Ereipichnus geladensis. Particle arrangement of the external coating is similar to that of terebelloid tubes, but Ereipichnus is a horizontal trace fossil, whereas structured worm tubes are vertical. The second type is a grain-coated trace fossil, tubular in shape, with a simple internal structure. The coating is often reddish with respect to the neighbouring dark grey sediment and shows a slightly coarser-grained texture, which envelopes the internal muddy pipe. This type, which yielded echinoids, was produced by irregular or heart-shaped sea-urchins (spatangoids) and is attributed to Scolicia or Cardioichnus. Facies analysis of the Serra Gelada succession with Ereipichnus and Scolicia or Cardioichnus locally shows other types of branched trace fossils (primarily represented by different forms of Thalassinoides) and bioturbation is developed in tiers, increasing upwards in abundance and diversity.

The study and application of ichnology, or trace fossils, have evolved substantially since trace fossils were first recognized (as such) in the late 19th century. Trace fossils were, in fact, initially interpreted as fossilized remains of marine algae (i.e. fucoids). This notion was not dispelled until A.G. Nathorst (1881) reinterpreted several fucoids — for example Chondrites , Zoophycos , and Palaeophycus — as the burrows of marine invertebrates. Both during the “age of fucoids” and for several decades thereafter, trace fossils were collected with the aim of determining diversities and temporal ranges of ichnofossil types, and the use of trace fossils as paleoecological indicators was not well developed. In the early part of the twentieth century, the ethologic and ecologic significance of ichnofossils was gradually recognized. In 1929, Rudolf Richter, an early leader in trace-fossil analysis, established the Senckenberg Vorschungstelle fur Meeresgeologie und Meerespalaontologie at Wilhelmshaven which was later known as “Senckenberg am Meer” (Senckenberg by the Sea). The purpose of this research station was to study animal-sediment relationships in modern depositional settings, in order to apply the actualistic concepts of Lyell to the ichnological record. An important abstraction needed to be embraced before trace fossils could be employed to aid in the identification of sedimentary environments. That is, a trace fossil represents a “behavior” employed by an animal to live in a sedimentary environment, and that the behavior is a physical response to chemical and physical depositional conditions. Conversely, ichnofossils can be used to interpret some sedimentary and chemical parameters of the depositional setting. …

Terrestrial and marine invertebrate organisms both leave records of their activities in the sediment in the form of trace fossils, at least during certain stages of their ontogeny. In contrast, trace fossils produced by vertebrate organisms are scarce, although terrestrial trace fossils provide exclusive insights into the social behaviour of their producers. In the marine realm, vertebrate trace fossils are relatively rare, difficult to identify and problematic to interpret. However, in certain settings, observations on serendipitously preserved and exposed trace fossils can shed light on the predatory behaviour of marine vertebrates. In Miocene outer shelf to nearshore sandstones of the Taliao Formation in NE Taiwan, large numbers of bowl-shaped trace fossils can be observed. Morphology and size range (diameter typically 10–30 cm, average depth around 10 cm) of these trace fossils agree well with feeding traces of modern stingrays, and the trace fossil Piscichnus waitemata, which has been attributed to bottom feeding rays. Stingrays direct a jet of water from their mouths to excavate a bowl-shaped pit to expose their prey. In the material filling the excavated bowl, broken pieces of two other common trace fossils, Ophiomorpha and Schaubcylindrichnus, are often found, and in a number of cases, vertical shafts of Ophiomorpha surrounded by dispersed pieces of wall material have been observed. In contrast, surrounding sediment rarely contains this kind of broken pieces of wall material. These observations clearly indicate that stingrays specifically targeted the producers of the trace fossils: thalassinoid crustaceans and worms, respectively. The targeted predation of these relatively deep burrowers furthermore suggests that the rays used their electroreceptive organs to locate the prey; as such, direct targeting of buried prey only based on olfactory senses has been shown to be ineffective in experiments with extant myliobatiform rays.