Trace fossils, also called ichnofossils (IPA: /ˈɪknoʊfɒsɨl/, Greek: ιχνος or ikhnos meaning "trace" or "track"), are geological records of biological activity. Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly Trace fossils may be impressions made on the substrate by an organism: for example, burrows, borings (bioerosion), footprints and feeding marks, and root cavities. A burrow is a hole or tunnel dug into the ground by an Animal to create a space suitable for habitation temporary refuge or as a byproduct of locomotion Bioerosion describes the Erosion of hard ocean substrates by living organisms by a number of mechanisms The term in its broadest sense also includes the remains of other organic material produced by an organism - for example coprolites (fossilized droppings) or chemical markers - or sedimentological structures produced by biological means - for example, stromatolites. A Coprolite is Fossilized animal dung Coprolites are classified as trace fossils as opposed to body fossils as they give evidence for the animal's behaviour (in Stromatolites (from Greek στρώμα strōma, mattress bed stratum and λιθος lithos, rock are layered accretionary Structures formed in Trace fossils contrast with body fossils, which are the fossilised remains of parts of organisms' bodies, usually altered by later chemical activity or mineralisation.
Sedimentary structures, for example those produced by empty shells rolling along the sea floor, are not produced through the behaviour of an organism and not considered trace fossils.
The study of traces is called ichnology, which is divided into paleoichnology, or the study of trace fossils, and neoichnology, the study of modern traces. Ichnology is the branch of Biology that deals with traces of organismal behavior This science is challenging, as most traces reflect the behaviour--not the biological affinity--of their makers. As such, trace fossils are categorised into form genera, based upon their appearance and the implied behaviour of their makers.
Contents |
Occurrence
Traces are better known in their fossilised form than in modern sediments. [1] This makes it difficult to interpret some fossils by comparing them with modern traces, even though they may be extant or even common. [1] The main difficulties in accessing extant burrows stem from finding them in consolidated sediment, and being able to access those formed in deeper water.
Trace fossils are best preserved in sandstones;[1] the grain size and depositional facies both contributing to the better preservation. They may also be found in shales and limestones. [1]
Classification
Trace fossils are generally difficult or impossible to assign to a specific maker. Trace fossils are classified in various ways for different purposes Only in very rare occasions are the makers found in association with their tracks. Further, entirely different organisms may produce identical tracks. Therefore conventional taxonomy is not applicable, and a comprehensive form taxonomy has been erected. At the highest level of the classification, five bahavioural modes are recognised:[1]
- Domichnia, dwelling structures reflecting the life position of the organism that created it.
- Fodinichnia, three-dimensional structures left by animals which eat their way through sediment, such as deposit feeders;
- Pascichnia, feeding traces left by grazers on the surface of a soft sediment or a mineral substrate;
- Cubichnia, resting traces, in the form of an impression left by an organism on a soft sediment;
- Repichnia, surface traces of creeping and crawling.
Fossils are further classified into form genera, a few of which are even subdivided to a "species" level. Classification is based on shape, form, and implied behavioural mode.
Information provided by ichnofossils
Because identical fossils can be created by a range of different organisms, trace fossils can only reliably inform us of two things: the consistency of the sediment at the time of its deposition, and the energy level of the depositional environment. [2] Attempts to deduce such traits as whether a deposit is marine or non-marine have been made, but shown to be unreliable. [2]
Paleoecology
Trace fossils provide us with indirect evidence of life in the past, such as the footprints, tracks, burrows, borings, and feces left behind by animals, rather than the preserved remains of the body of the actual animal itself. Unlike most other fossils, which are produced only after the death of the organism concerned, trace fossils provide us with a record of the activity of an organism during its lifetime.
Trace fossils are formed by organisms performing the functions of their everyday life, such as walking, crawling, burrowing, boring, or feeding. Tetrapod footprints, worm trails and the burrows made by clams and arthropods are all trace fossils. Tetrapods ( Greek τετραποδη tetrapoda, Latin Quadruped, "four-footed" are Vertebrate Animals A worm is a common name given to a diverse group of invertebrate animals that have a long soft body and no legs Clam is a word which can be used for all some or only a few Species of Bivalve Mollusks the word is a Common name which has Arthropods are Animals belonging to the Phylum Arthropoda (from Greek ἄρθρον arthron, " Joint "
Perhaps the most spectacular trace fossils are the huge, three-toed footprints produced by dinosaurs and related archosaurs. Archosaurs ( Greek for 'ruling lizards' are a group of Diapsid Reptiles represented by Modern birds and Crocodilians This group also These imprints give scientists clues as to how these animals lived. Although the skeletons of dinosaurs can be reconstructed, only their fossilized footprints can determine exactly how they stood and walked. FOSSIL is a standard protocol for allowing serial communication for Telecommunications programs under the DOS Operating system. Such tracks can tell much about the gait of the animal which made them, what its stride was, and whether or not the front limbs touched the ground.
However, most trace fossils are rather less conspicuous, such as the trails made by segmented worms or nematodes. The annelids, collectively called Annelida (from Latin anellus "little ring" are a large phylum of Animals comprising The nematodes or roundworms ( Phylum Nematoda from Greek (nema "thread" + -ode "like" are one of the most common Some of these worm castings are the only fossil record we have of these soft-bodied creatures. A worm is a common name given to a diverse group of invertebrate animals that have a long soft body and no legs
Palæoenvironment
Fossil footprints made by tetrapod vertebrates are difficult to identify to a particular species of animal, but they can provide us with valuable information such as the speed, weight, and behavior of the organism that made them. Vertebrates are members of the Subphylum Vertebrata, Chordates with backbones or spinal columns The grouping sometimes includes Such trace fossils are formed when amphibians, reptiles, mammals or birds walked across soft (probably wet) mud or sand which later hardened sufficiently to retain the impressions before the next layer of sediment was deposited. Prehistoric amphibian Amphibians (class Amphibia such as Frogs Toads Salamanders Newts Gymnophiona, Sirens and Reptiles, or members of the class Reptilia are air-breathing Cold-blooded Vertebrates that have skin covered in scales as opposed to hair or feathers Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands Birds ( class Aves) are bipedal endothermic ( Warm-blooded) Vertebrate animals that lay eggs. Some fossils can even provide details of how wet the sand was when they were being produced, and hence allow estimation of palæo-wind directions. [3]
Assemblages of trace fossils occur at certain water depths,[1] and can also reflect the salinity and turbidity of the water column.
Stratigraphic correlation
Some trace fossils can be used as local index fossils, to date the rocks in which they are found, such as the burrow Arenicolites franconicus which occurs only in a 4 cm (1. Index fossils (also known as guide fossils or zone fossils are Fossils used to define and identify geologic periods (or faunal stages A U-shaped Ichnotaxon dating from Ediacaran times onwards 6") layer of the Triassic Muschelkalk epoch, throughout wide areas in southern Germany. The Triassic is a geologic period and system that extends from about 251 to 199 Ma (million years ago Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. [4]
The base of the Cambrian period is defined by the first appearance of the trace fossil Trichophycus pedum. Trichophycus pedum (or Treptichnus pedum; formerly Phycodes pedum) is regarded as the earliest widespread complex Trace fossil [5]
Trace fossils have a further utility as many appear before the organism thought to create them, extending their stratigraphic range. [6]
Ichnofacies
Trace fossil assemblages are far from random; the range of fossils recorded in association is constrained by the environment in wheich the trace-making organisms dwelt. An ichnofacies is an assemblage of Trace fossils that provide an indication of the conditions that their formative organisms inhabited [1] Palaeontologist Adolf Seilacher pioneered the concept of ichnofacies, whereby the state of a sedimentary system at its time of deposition could be implied by noting the fossils in association with one another. Adolf "Dolf" Seilacher (b February 24 1925) is a German palaeontologist who has made major contributions to evolutionary and ecological palaeobiology in a career stretching [1]
Inherent bias
Most trace fossils are known from marine deposits. Essentially, there are two types of traces, either exogenic ones, which are made on the surface of the sediment (such as tracks) or endogenic ones, which are made within the layers of sediment (such as burrows).
Surface trails on sediment in shallow marine environments stand less chance of fossilization because they are subjected to wave and current action. Conditions in quiet, deep-water environments tend to be more favorable for preserving fine trace structures.
Most trace fossils are usually readily identified by reference to similar phenomena in modern environments. However, the structures made by organisms in recent sediment have only been studied in a limited range of environments, mostly in coastal areas, including tidal flats. Mudflats (also tidal flats, tide flats, etc are coastal wetlands that form when mud is deposited by tides or rivers
Evolution
Putative "burrows" dating as far back as 1100 million years may have been made by animals which fed on the undersides of microbial mats, which would have shielded them from a chemically unpleasant ocean;[7] however their uneven width and tapering ends make a biological origin difficult to defend. [8] The first evidence of burrowing which is widely accepted dates to the Ediacaran period, around . During this period, burrows are horizontal, or just below the surface. Such burrows must have been made by motile organisms with heads, which would probably have been bilateran animals. The Bilateria (ˌbaɪləˈtɪəriə are all animals having a bilateral symmetry, i [9] The burrows observed imply simple behaviour, and the complex, efficient feeding traces common from the start of the ensuing Cambrian period are absent. Some Ediacaran fossils, especially discs, have been interpreted tentatively as trace fossils, but this hypothesis has not gained widespread acceptance. As well as burrows, some trace fossils have been found directly associated with an Ediacaran fossil. Yorgia and Dickinsonia are often found at the end of long pathways of trace fossils matching their shape;[10] the method of formation of these disconnected and overlapping fossils largely remains a mystery. Yorgia waggoneri Ivantsov 1999is a member of the Ediacara biota, and resembles the organisms Dickinsonia and Spriggina. Dickinsonia is an iconic fossil of the Ediacaran biota. It (roughly resembles a bilaterally symmetrical ribbed oval The potential mollusc Kimberella is associated with scratch marks thought to have been formed by its radula,[11] further traces from appear to imply active crawling or burrowing activity. Molluscs are animals belonging to the phylum Mollusca. There are around 250000 extant Species within the phylum with an estimated 70000 The radula is a toothed Chitinous ribbon typically used for scraping cutting and chewing food before it enters the Esophagus. [11]
As the Cambrian got underway, new forms of trace fossil appeared, including vertical burrows[12] and traces normally attributed to arthropods. Arthropods are Animals belonging to the Phylum Arthropoda (from Greek ἄρθρον arthron, " Joint " [13] These represent a “widening of the behavioural repertoire”,[14] both in terms of abundance and complexity. [15]
Trace fossils are a particularly significant source of data from this period because they represent a data source that is not directly connected to the presence of easily-fossilized hard parts, which are rare during the Cambrian. Whilst exact assignment of trace fossils to their makers is difficult, the trace fossil record seems to indicate that at the very least, large, bottom-dwelling, bilaterally symmetrical organisms were rapidly diversifying during the early Cambrian. "Bilateral symmetry" redirects here For bilateral symmetry in mathematics see Reflection symmetry. [16]
Further, less rapid diversification occurred since, and many traces have been converged upon independently by unrelated groups of organisms. [1]
Trace fossils also provide our earliest evidence of animal life on land. The earliest arthropod trackways date to the Cambro-Ordovician,[17] and trackways from the Ordovician Tumblagooda sandstone allow the behaviour of these organisms to be determined. The Tumblagooda sandstone is a Geological formation deposited during the Silurian or Ordovician periods around four to five hundred million years ago [3] The enigmatic trace fossil Climactichnites may represent an earlier still terrestrial trace, perhaps made by a slug-like organism. Climactichnites is an enigmatic late Cambrian fossil formed on sandy tidal flats around.
Common ichnogenera
- Skolithos: One well-known occurrence of Cambrian trace fossils from this period is the famous 'Pipe Rock' of northwest Scotland. Skolithos (formerly spelt Scolithus or Skolithus) is a common Trace fossil Ichnogenus whose original form Scotland ( Gaelic: Alba) is a Country in northwest Europethat occupies the northern third of the island of Great Britain. The 'pipes' that give the rock its name are closely packed straight tubes- which were presumably made by some kind of worm-like organism. A worm is a common name given to a diverse group of invertebrate animals that have a long soft body and no legs The name given to this type of tube or burrow is Skolithos, which may be 30 cm (12") in length and between 2 to 4 cm (0. 8 to 1. 6") in diameter. Such traces are known worldwide from sands and sandstones deposited in shallow water environments, from the Cambrian period (542 to 488 m. Sandstone is a Sedimentary rock composed mainly of Sand -size Mineral or rock grains. The Cambrian is a geologic period and system that began about Ma (million years ago at the end of the Proterozoic eon and ended about Ma with y. a) onwards.
- Chondrites are small branching burrows of the same diameter, which superficially resemble the roots of a plant. Chondrites are stony Meteorites that have not been modified due to Melting or Differentiation of the parent body The most likely candidate for having constructed these burrows is a nematode (roundworm). The nematodes or roundworms ( Phylum Nematoda from Greek (nema "thread" + -ode "like" are one of the most common Chondrites are found in marine sediments from the Cambrian period of the Paleozoic onwards. The Cambrian is a geologic period and system that began about Ma (million years ago at the end of the Proterozoic eon and ended about Ma with The Paleozoic or Palaeozoic Era (from the Greek palaio (παλαιο "old" and zoe (ζωη "life" meaning "ancient life" They are especially common in sediments which were deposited in reduced-oxygen environments.
- Cruziana are excavation trace marks made on the sea floor which have a two-lobed structure with a central groove. Cruziana is a Trace fossil consisting of elongate bilobed approximately bilaterally symmetrical burrows usually preserved along bedding planes with a sculpture The lobes are covered with scratch marks made by the legs of the excavating organism, usually a trilobite or allied arthropod and, in fact, several different types of trilobite have been discovered at the end of Cruziana trails. Trilobites ("three-lobes" are extinct Arthropods that form the class Trilobita. Cruziana are most common in marine sediments formed during the Paleozoic era, particularly in rocks from the Cambrian and Ordovician periods. The Paleozoic or Palaeozoic Era (from the Greek palaio (παλαιο "old" and zoe (ζωη "life" meaning "ancient life" The Cambrian is a geologic period and system that began about Ma (million years ago at the end of the Proterozoic eon and ended about Ma with The Ordovician is a geologic period and system, the second of six of the Paleozoic era, and covers the time between 488 Over 30 species of Cruziana have been identified.
- Thalassinoides are burrows which occur parallel to the bedding plane of the rock and are extremely abundant in rocks, worldwide, from the Jurassic period onwards. Thalassinidea is an Infraorder of decapod Crustaceans that live in Burrows in Muddy bottoms of the world's Oceans In The Jurassic is a geologic period and system that extends from about Ma (million years ago to Ma that is from the end of the Triassic to the beginning They are repeatedly branched, with a slight swelling present at the junctions of the tubes. The burrows are cylindrical and vary from 2 to 5 cm (0. 8" to 2") in diameter. Thalassinoides sometimes contain scratch marks, droppings or the bodily remains of the crustaceans which made them. Structure of crustaceans As Arthropods crustaceans have a stiff Exoskeleton, which must be shed to allow the animal to grow ( Ecdysis or molting
- Asteriacites is the name given to the five-rayed fossils found in rocks and they record the resting place of starfish on the sea floor. Asteriacites is the name given to five-rayed Fossils found in rocks Starfish (also called sea stars) are any Echinoderms belonging to the class Asteroidea. Asteriacites are found in European and American rocks, from the Ordovician period onwards; and are numerous in rocks from the Jurassic period of Germany. The Ordovician is a geologic period and system, the second of six of the Paleozoic era, and covers the time between 488 The Jurassic is a geologic period and system that extends from about Ma (million years ago to Ma that is from the end of the Triassic to the beginning Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe.
- Rhizocorallium is a type of burrow, the inclination of which is typically within 10° of the bedding planes of the sediment. Rhizocorallium is an Ichnogenus type of Burrow, the inclination of which is typically within 10° of the bedding planes of the Sediment. A burrow is a hole or tunnel dug into the ground by an Animal to create a space suitable for habitation temporary refuge or as a byproduct of locomotion These burrows can be very large, over a meter long in sediments that show good preservation, e. g. Jurassic rocks of the Yorkshire Coast (eastern United Kingdom), but the width is usually only up to 2 cm, restricted by the size of the organisms producing it. The Jurassic is a geologic period and system that extends from about Ma (million years ago to Ma that is from the end of the Triassic to the beginning Yorkshire is a historic county of Northern England and the largest in Great Britain. The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located It is thought that they represent fodinichnia as the animal (probably a nematode) scoured the sediment for food. The nematodes or roundworms ( Phylum Nematoda from Greek (nema "thread" + -ode "like" are one of the most common Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of
- Teichichnus has a distinctive form produced by the stacking of thin 'tongues' of sediment, atop one another. Teichichnus is an Ichnogenus with a distinctive form produced by the stacking of thin 'tongues' of Sediment, atop one another Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of They are again believed to be fodinichnia, with the organism adopting the habit of retracing the same route through varying heights of the sediment, which would allow it to avoid going over the same area. These 'tongues' are often quite sinuous, reflecting perhaps a more nutrient-poor environment in which the feeding animals had to cover a greater area of sediment, in order to acquire sufficient nourishment.
- Protichnites consists of two rows of tracks and a linear depression between the two rows. Protichnites is a genus of Trace fossil consisting of the imprints made by the walking activity of Arthropods It is likely that more than one type of arthropod The tracks are believed to have been made by the walking appendages of arthropods. Arthropods are Animals belonging to the Phylum Arthropoda (from Greek ἄρθρον arthron, " Joint " The linear depression is thought to be the result of a dragging tail. The structures bearing this name were typically made on the tidal flats of Paleozoic seas, but similar ones extend into the Cenozoic. The Paleozoic or Palaeozoic Era (from the Greek palaio (παλαιο "old" and zoe (ζωη "life" meaning "ancient life" The Cenozoic (also Caenozoic or Cainozoic) Era (ˌsiːnəˈzoʊɪk/ /ˌsɛn- (meaning "new life" ( Greek ( kainos) "new"
- Climactichnites is the name given to trackways that usually consist of two parallel ridges separated by chevron-shaped raised cross bars. Climactichnites is an enigmatic late Cambrian fossil formed on sandy tidal flats around. They somewhat resemble tire tracks, and are larger (typically about four inches wide) than most of the other trace fossils made by invertebrates. An invertebrate is an Animal lacking a Vertebral column. The group includes 98% of all animal Species — all animals except those in the Chordate The tracks were produced on sandy tidal flats during late Cambrian time. The Cambrian is a geologic period and system that began about Ma (million years ago at the end of the Proterozoic eon and ended about Ma with While the identity of the animal is still conjectural, it may have been a large slug-like animal - its trackways produced as it crawled over and processed the wet sand to obtain food. Slug is a common non-scientific word which is often applied to any Gastropod mollusk whatsoever that has a very reduced shell a small internal shell
Other notable trace fossils
Less ambiguous than the above ichnogenera, are the traces left behind by invertebrates such as Hibbertopterus, a giant "sea scorpion" or eurypterid of the early Paleozoic era. An invertebrate is an Animal lacking a Vertebral column. The group includes 98% of all animal Species — all animals except those in the Chordate Hibbertopterus is a genus of giant Sea scorpions (class Eurypterida) extinct 250 million years ago thought to have inhabited the Swamps of The eurypterids (sea scorpions include the largest known Arthropod that ever lived (with the possible exception of Arthropleuridae) The eurypterids (sea scorpions include the largest known Arthropod that ever lived (with the possible exception of Arthropleuridae) The Paleozoic or Palaeozoic Era (from the Greek palaio (παλαιο "old" and zoe (ζωη "life" meaning "ancient life" This marine arthropod produced a spectacular hibbertopteroid track preserved in Scotland. Arthropods are Animals belonging to the Phylum Arthropoda (from Greek ἄρθρον arthron, " Joint " [18]
Bioerosion through time has produced a magnificent record of borings, gnawings, scratchings and scrapings on hard substrates. Bioerosion describes the Erosion of hard ocean substrates by living organisms by a number of mechanisms These trace fossils are usually divided into macroborings[19] and microborings[20]. Bioerosion intensity and diversity is punctuated by two events. One is called the Ordovician Bioerosion Revolution (see Wilson & Palmer, 2006) and the other was in the Jurassic[21]. For a comprehensive bibliography of the bioerosion literature, please see the External links below.
The oldest types of tetrapod tail-and-foot prints date back to the latter Devonian period. Tetrapods ( Greek τετραποδη tetrapoda, Latin Quadruped, "four-footed" are Vertebrate Animals The Devonian is a geologic period and system of the Paleozoic era spanning from to million years ago. These vertebrate impressions have been found in Ireland, Scotland, Pennsylvania, and Australia. Vertebrates are members of the Subphylum Vertebrata, Chordates with backbones or spinal columns The grouping sometimes includes Ireland (pronounced /ˈaɾlənd/ Éire) is the third largest island in Europe, and the twentieth-largest island in the world Scotland ( Gaelic: Alba) is a Country in northwest Europethat occupies the northern third of the island of Great Britain. The Commonwealth of Pennsylvania ( often colloquially referred to as PA (its abbreviation by natives and Northeasterners is a state located in the Northeastern For a topic outline on this subject see List of basic Australia topics.
Important human trace fossils are the Laetoli (Tanzania) footprints, imprinted in volcanic ash 3. Human evolution, or anthropogenesis, is the part of biological Evolution concerning the emergence of Homo sapiens as a distinct Species Laetoli is a site in Tanzania, dated to the Plio-Pleistocene and famous for its Hominid footprints preserved in Volcanic ash (Site G Tanzania ˌtænzəˈniːə officially the United Republic of Tanzania (Jamhuri ya Muungano wa Tanzania is a country in East Africa bordered by Kenya 7 million years ago (mya) -- probably by an early Australopithecus. In Astronomy, Geology, and Paleontology, mya or " mya " is an abbreviation for "million years ago". The Genus Australopithecus ( Latin australis "of the south" Greek πίθηκος pithekos "ape"
Confusion with other types of fossils
Trace fossils should not be confused with body casts. The Ediacara biota, for instance, primarily comprises the casts of organisms in sediment.
Early geologists gave the name 'fucoid' to a wide variety of markings they found on the bedding planes of sedimentary rocks. Sedimentary rock is one of the three main rock types (the others being igneous and Metamorphic rock) The earth scientists frequently misinterpreted these 'fucoid' marks as being the fossilized remains of seaweed. Seaweed is a loose colloquial term encompassing macroscopic Multicellular, benthic marine Algae. However, in more recent years, these markings have been studied with greater thoroughness. It is now apparent that the 'fucoids' and other markings have in fact been caused by a variety of plants and animals. As a result, these 'fucoid' markings are now termed trace fossils.
Pseudofossils, which are not true fossils, should also not be confused with ichnofossils, which are true indications of prehistoric life. Pseudofossils are Inorganic objects markings or impressions that might be mistaken for Fossils Pseudofossils may be misleading as some types of mineral deposits
 Numerous borings in a Cretaceous cobble, Faringdon, England; see Wilson (1986). |  Sponge borings and encrusters on a modern bivalve shell, North Carolina. |  Helminthopsis ichnosp. ; a trace fossil from the Logan Formation (Lower Carboniferous) of Wooster, Ohio. |
See also
- Bioerosion
- Bird ichnology
- The Geological timescale
- Ichnite - fossilised footprints
- Ichnofacies
- Trace fossil classification
References
- ^ a b c d e f g h i Seilacher, A. Bioerosion describes the Erosion of hard ocean substrates by living organisms by a number of mechanisms Bird Ichnology is the study of Avian life traces in Ornithology and Paleontology. The geologic time scale is a chronologic schema (or idealized Model) relating Stratigraphy to time that is used by Geologists and other An ichnite ( Greek " ιχνιον " ( ichnion) - a track trace or footstep is a fossilised footprint An ichnofacies is an assemblage of Trace fossils that provide an indication of the conditions that their formative organisms inhabited Trace fossils are classified in various ways for different purposes (1967). "Bathymetry of trace fossils". Marine Geology 5 (5-6): 413-428. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. ISSN 0025-3227. An International Standard Serial Number ( ISSN) is a unique eight-digit number used to identify a print or electronic Periodical publication.
- ^ a b Woolfe, K. J. (1990). "Trace fossils as paleoenvironmental indicators in the Taylor Group (Devonian) of Antarctica". Palaeogeography, Palaeoclimatology, Palaeoecology 80: 301-310.
- ^ a b Trewin, N. H. ; McNamara, K. J. (1995). "Arthropods invade the land: trace fossils and palaeoenvironments of the Tumblagooda Sandstone (? late Silurian) of Kalbarri, Western Australia". Transactions of the Royal Society of Edinburgh: Earth Sciences 85: 177-210.
- ^ Schlirf, M. (2006). "Trusheimichnus New Ichnogenus From the Middle Triassic of the Germanic Basin, Southern Germany". Ichnos 13 (4): 249-254.
- ^ Gehling, James (March 2001). "Burrowing below the basal Cambrian GSSP, Fortune Head, Newfoundland". Geological Magazine 138 (2): 213-218. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ e. g. Seilacher, A. (1994). "How valid is Cruziana Stratigraphy?". International Journal of Earth Sciences 83 (4): 752–758.
- ^ Seilacher, A.; Bose, P. Adolf "Dolf" Seilacher (b February 24 1925) is a German palaeontologist who has made major contributions to evolutionary and ecological palaeobiology in a career stretching K. ; Pflüger, F. (1998-10-02). Year 1998 ( MCMXCVIII) was a Common year starting on Thursday (link will display full 1998 Gregorian calendar) Events 1187 - Siege of Jerusalem: Saladin captures Jerusalem after 88 years of Crusader rule "Triploblastic Animals More Than 1 Billion Years Ago: Trace Fossil Evidence from India". Science 282 (5386): 80-83. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ Budd, G. E. ; Jensen, S. (2000). "A critical reappraisal of the fossil record of the bilaterian phyla". Biological Reviews 75 (02): 253-295. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ Fedonkin, M. A. (1992). "Vendian faunas and the early evolution of Metazoa". in Lipps, J. , and Signor, P. W. , eds. , Origin and early evolution of the Metazoa: New York, Plenum Press. : 87–129. Springer.
- ^ Ivantsov, A. Y. ; Malakhovskaya, Y. E. (2002). "Giant Traces of Vendian Animals" (in Russian; English translation available). Doklady Earth Sciences (Doklady Akademii Nauk) 385 (6): 618-622. ISSN 1028-334X. An International Standard Serial Number ( ISSN) is a unique eight-digit number used to identify a print or electronic Periodical publication.
- ^ a b According to Martin, M. W. ; Grazhdankin, D. V. ; Bowring, S. A. ; Evans, D. A. D. ; Fedonkin, M. A. ; Kirschvink, J. L. (2000-05-05). 2000 ( MM) was a Leap year that started on Saturday of the Common Era, in accordance with the Gregorian calendar. Events 553 - The Second Council of Constantinople begins 1215 - Rebel Barons renounce their allegiance to King John "Age of Neoproterozoic Bilatarian Body and Trace Fossils, White Sea, Russia: Implications for Metazoan Evolution". Science 288 (5467): 841. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. For a more cynical perspective see Butterfield, N. J. (2006). "Hooking some stem-group "worms": fossil lophotrochozoans in the Burgess Shale". Bioessays 28 (12): 1161-6. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ e. g. Diplocraterion and Skolithos
- ^ Such as Cruziana and Rusophycus. Skolithos (formerly spelt Scolithus or Skolithus) is a common Trace fossil Ichnogenus whose original form Cruziana is a Trace fossil consisting of elongate bilobed approximately bilaterally symmetrical burrows usually preserved along bedding planes with a sculpture Rusophycus is a trace fossil allied to Cruziana. Rusophycus is the resting trace recording the outline of the tracemaker Cruziana Details of Cruziana’s formation are reported by Goldring, R. (1985). "The formation of the trace fossil Cruziana". Geological Magazine 122 (1): 65–72.
- ^ Conway Morris, S. (1989). "Burgess Shale Faunas and the Cambrian Explosion". Science 246 (4928): 339. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ Jensen, S. (2003). "The Proterozoic and Earliest Cambrian Trace Fossil Record; Patterns, Problems and Perspectives". Integrative and Comparative Biology 43: 219–228. The Society for Integrative and Comparative Biology. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ Although some cnidarians are effective burrowers, e. Cnidaria (naɪˈdɛəriə is a phylum containing some 9000 Species of Animals found exclusively in aquatic mostly marine, environments g. Weightman, J. O. ; Arsenault, D. J. (2002). "Predator classification by the sea pen Ptilosarcus gurneyi (Cnidaria): role of waterborne chemical cues and physical contact with predatory sea stars" 80 (1): 185–190. most Cambrian trace fossils have been assigned to bilaterian animals.
- ^ MacNaughton, R. B. ; Cole, J. M. ; Dalrymple, R. W. ; Braddy, S. J. ; Briggs, D. E. G. ; Lukie, T. D. (2002). "First steps on land: Arthropod trackways in Cambrian-Ordovician eolian sandstone, southeastern Ontario, Canada". Geology 30 (5): 391-394. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ Whyte, MA (2005)). "Palaeoecology: A gigantic fossil arthropod trackway. ". Nature 438.
- ^ Wilson, M. A. , 2007. Macroborings and the evolution of bioerosion, p. 356-367. In: Miller, W. III (ed. ), Trace Fossils: Concepts, Problems, Prospects. Elsevier, Amsterdam, 611 pages.
- ^ * Glaub, I. , Golubic, S. , Gektidis, M. , Radtke, G. and Vogel, K. , 2007. Microborings and microbial endoliths: geological implications. In: Miller III, W (ed) Trace fossils: concepts, problems, prospects. Elsevier, Amsterdam: pp. 368-381.
- Glaub, I. and Vogel, K. , 2004. The stratigraphic record of microborings. Fossils & Strata 51:126-135.
- ^
- Taylor, P. D. and Wilson, M. A. , 2003. Palaeoecology and evolution of marine hard substrate communities. Earth-Science Reviews 62: 1-103. [1]
- Bromley, R. G. , 1970. Borings as trace fossils and Entobia cretacea Portlock as an example, p. 49-90. In: Crimes, T. P. and Harper, J. C. (eds. ), Trace Fossils. Geological Journal Special Issue 3.
- Bromley, R. G. , 2004. A stratigraphy of marine bioerosion. In: The application of ichnology to palaeoenvironmental and stratigraphic analysis. (Ed. D. McIlroy), Geological Society of London Special Publications 228:455-481.
- Palmer, T. J. , 1982. Cambrian to Cretaceous changes in hardground communities. Lethaia 15:309-323.
- Wilson, M. A. , 1986. Coelobites and spatial refuges in a Lower Cretaceous cobble-dwelling hardground fauna. Palaeontology 29:691-703.
- Wilson, M. A. and Palmer, T. J. , 2006. Patterns and processes in the Ordovician Bioerosion Revolution. Ichnos 13: 109-112. [2]
- Yochelson, E. L. and Fedonkin, M. A. , 1993. Paleobiology of Climactichnites, and Enigmatic Late Cambrian Fossil. Smithsonian Contributions to Paleobiology 74:1-74.
External links
- http://www.peripatus.gen.nz/paleontology/trafos.html
- http://www.envs.emory.edu/ichnology/
- Bioerosion Website at The College of Wooster
- Comprehensive bioerosion bibliography compiled by Mark A. Wilson
Dictionary
trace fossil
-noun
- A type of fossil reflecting the reworking of sediments and hard substrates by organisms, rather than the physical remains of the organism itself. This includes structures such as burrows, trails, impressions, coprolites and borings.
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic