Cruziana
Cruziana is the name of a trace fossil genus (Ichnogenus) of the Paleozoic and Early Mesozoic Era . In Cruziana in the strict exclusive sense, is a band-like bilaterally travel or combined locomotion and feeding track (Repichnion) generated either directly on or just below the surface of a body of water sediment (usually a sea). In a broader, more inclusive sense, Cruziana alsoincludestraces of locomotion and rest (Cubichnia), which are often assigned to the trace genera Rusophycus or Isopodichnus . Cruziana and Rusophycus werecaused by trilobites , but very likely other arthropods as well . Isopodichnus has never been caused by trilobites with relative certainty.
Due to their characteristic morphology, as it is in typical tradition as a relief on the underside of the layer, i.e. H. when filling in the actual trace occurs, Cruziana , Rusophycus , Isopodichnus and a few other, similar trace fossils are also referred to as bilobites .
Research history
The name Cruziana was coined in 1842 by the French naturalist Alcide Dessalines d'Orbigny in a part of his work Voyage dans l'Amerique méridionale . Under the names Cruziana rugosa and C. furcifer he described fossils from the Caradoc (late Ordovician ) of Liriuni near Cochabamba in Bolivia. Believing that it was a matter of body fossils, d'Orbigny Cruziana classified among other things together with trilobites among the articulated animals ("animaux articulés"). Originally, he had chosen the name " Bilobites " for the genus , and this name is actually used in the captions of the pictures belonging to the description, but previously published. Below d'Orbigny had, however, learned that the name " Bilobites " already by the American James Ellsworth DeKay was used for fossil shells, and changed the name in honor of South American independence fighter Andres de Santa Cruz in Cruziana . Apparently DeKay did not use “ Bilobites ” in the sense of a generic name, but simply as the English plural form of the word “Bilobit”. However, the American Constantine Samuel Rafinesque-Schmaltz had already described a trilobite under the name Bilobites in 1831 (today a noun dubium ), which is why the renaming made sense. The informal terms “bilobite” or “bilobite” are still used today as a collective term for traces with a Cruziana- like morphology (see sections Rusophycus and Isopodichnus ).
Conservation and morphology
Cruziana is mostly preserved on the underside of sandstone banks as a so-called convex hyporelief. The sandstone bank usually represents a storm deposit (tempestite) that has filled in traces created on the sediment surface. In some cases, cruziana produced in the sediment can be previously, i.e. H. during the storm, by the action of bottom-contacting waves . In rare cases, Cruziana is also called Epirelief, i.e. H. on top of layers.
As a hyporelief, Cruziana shows the typical bilobate morphology, which gave its name to the originally selected generic name " Bilobites ", i. H. it consists of two equally large, parallel, usually relatively wide and closely spaced bulges ("lobes"), which are separated from one another by a central, continuous, usually relatively narrow furrow. The ridges have a welt that runs like a herringbone either obliquely or transversely to the central furrow.
Two subtypes can be roughly distinguished: the ribbon-like “ Cruziana Sensu stricto ” and the short, oval (“coffee bean-shaped”) or teardrop-shaped forms, which are usually called Rusophycus . The width of a track is typically more than one and significantly less than ten centimeters. The ribbon-like tracks can reach a length of several meters and run either straight or in relatively wide arcs. Several such arcs intersect on a layer surface is also called "grinding" (Engl .: loops spoken).
interpretation
Cruziana sensu stricto is interpreted as the locomotion or combined locomotion and feeding track of trilobites and other, morphologically and ecologically similar arthropods.
The famous German paleichnologist Adolf Seilacher postulates that trilobites produced cruziana while they moved horizontally, half-buried in the sediment and at the same time combed it for organic particles (Seilacher describes this behavior with the word plowing ). The praises are the result of the “shoveling” of sediment towards the middle of the track, under the trunk of the trilobite. The stripes on the praises go back to the activity of the parts (endopodites) of the arthropod legs in the sediment that function as running and digging tools . The movement of the endopodite was medio-posterior, i.e. that is, their distal ends also moved toward the end of the body while being attracted to the longitudinal axis of the body. According to this hypothesis, the "V", which is usually formed by the transverse flow on the lobes, pointed with the open side in the direction of movement of the animal. Food particles that were "sifted" from the sediment by the exopodites and shoveled into the food channel on the ventral side were passed on by the coxae , the most proximal (closest to the torso) leg links, into the head region to the mouth opening. The fact that Cruziana , unlike pasture tracks in the narrower sense (Pascichnia), does not form meanders , but straight bands or wide arcs, is due to the physique of the trilobites, which do not allow them to run tight curves.
Some Cruziana- ichnospecies show in addition to the transverse stripes also a clearly more finely developed longitudinal striations, which are interpreted as stripes (English: " brushings ") of the feather-like gills that sat on the exopodites of the trilobite legs .
It is undisputed that the stripe patterns, including the "brushings", as well as other special features of the various Cruziana ichnospecies, are closely related to the anatomy, especially the legs, of the producing arthropod. This relationship is also known as “fingerprinting”.
Producer
Cruziana is often referred to simply as the "trilobite trail". In numerous cases this may be true, and in some cases a close stratigraphic and spatial association between tracks and trilobites has been proven, for example between the Ichnospecies Cruziana semiplicata and the trilobite genus Maladioidella in the Upper Cambrian of Oman (Andam Formation) and, in a relatively close association , even in layers of the same age in Spain and Wales. However, Cruziana also occurs in deposits that are younger or originate from a different deposit environment than those in which body fossils of trilobites occur. So Cruziana detected in freshwater deposits and in Triassic sediments or both.
An active palaeontological work shows that Cruziana -like traces are also produced by the back shell (Notostraca) Triops , the " tadpole shrimp ", and, contrary to what Seilacher suspects for trilobites, directly on the sediment surface (for Cruziana in freshwater sediments see also Isopodichnus and occurrence ).
Rusophycus
Since the 1970s, Seilacher has considered all larger bilobatic traces with transverse flow, regardless of whether they are ribbon-like or not, as cruziana . However, other editors distinguish ribbon -like traces of movement (“ Cruziana sensu strictu”) from non-ribbon-like, oval (“coffee bean-shaped”) bilobatic traces of rest (Cubichnia), which they classify in the Ichnogenus Rusophycus . Seilacher only informally summarizes the ribbon-like forms under the attribute 'cruzianaeform', and he describes the short oval ones as 'rusophyciform'.
The reason for Seilacher's synonymization is that he regards Cruziana not only as a locomotion, but above all as a feeding or grazing track (Pascichnion) and Rusophycus not only as a resting track, but also as a horizontally stationary feeding track. Especially the Ichnospecies Rusophycus leiferikssoni (or Cruziana leiferikssoni ), which represents a relatively deep structure, makes this view seem plausible. For the hardly less important palichnologist Richard Bromley this synonymization is inadmissible, since Cruziana and Rusophycus are obviously due to different behaviors of the trace producer (horizontal movement vs. stationary "digging"), which clearly justifies an assignment to different types of trace.
Interestingly, the fossil material, on the basis of which the trace genus Cruziana was established at the time, actually represents shapes that are not to be addressed as ribbon-like, but as oval to coffee bean-shaped and thus come closer to the current concept of the genus Rusophycus than the current concept of the genus Cruziana (sensu strictu). Rusophycus itself was built in 1852 by the American James Hall on the assumption that they were plants. The type material from the Clinton group (early Silurian) of Oneida County in the US state of New York includes both the oval shapes, which correspond to the actual understanding of the genus today, as well as the ribbon-like shapes, which are now always referred to as Cruziana . For this reason, the names Cruziana and Rusophycus as well as Bilobites were used by different authors for the same fossils for a long time , until in the 1950s, of all people, Seilacher made the separation of the two generic concepts that is now accepted by most Palichnologists, but not by Seilacher.
Isopodichnus
Bilobate tracks with a width of no more than one centimeter, which occur in continental sediments of the higher Paleozoic and Triassic periods, are traditionally grouped under the generic name Isopodichnus . Since this traditional concept of the trace genus includes both cruziana-like ribbon-like traces and rusophyciform "rest traces", i.e. traces that have arisen from different activities, but from the same activities to which Cruziana and Rusophycus also go back, they are from Bromley classified under the two last-mentioned trace genera. Bromley and colleagues also provide convincing evidence that the Triassic forms of " Isopodichnus " were produced by small crustaceans from the group of back peelers (Notostraca). More recent work also assign Permian isopodichnus to the activity of these small crustaceans .
Occurrence
Cruziana (including Rusophycus ) is a typical trace fossil of flat marine sandstones of the Paleozoic Era, although it is found worldwide in flat marine limestones.
Large, "robust" Cruziana have been found up to the Triassic, but so far only in marine environments . In the terrestrial environment, only the small, both cruzianae and rusophyciform traces, traditionally called " Isopodichnus ", appear. These are u. a. from the Devonian continental Old Red sandstone of Scotland, from Upper Carboniferous meltwater lake sediments of the Agua Colorada Formation (Argentina) and Seaham Formation (New South Wales, Australia), from the Abo Formation ( Lower Permian of New Mexico) and from the " Saxon ”from the Permo-Mesozoic southwestern border of the French Massif Central (Lodève Basin) as well as from various Triassic deposits, including the German red sandstone and from the Upper Triassic of the Newark supergroup .
A relatively frequent occurrence of Cruziana sensu strictu and Rusophycus in deep marine deposits has been reported from the Cambrian and Ordovician of Eastern Canada. Post-Ordovician deep-marine occurrences of these types of trace, however, are very rare.
Cruziana -Ichnostratigraphy
Cruziana is the first trace fossil on which a detailed biostratigraphic scheme was developed. Once again Adolf Seilacher was instrumental in its creation. The development was accelerated, among other things, by the fact that continental and marginal sandstones of the so-called Nubian facies , which make up large parts of the Paleozoic-Mesozoic series in the old sedimentary basins of North Africa and the Middle East, are important potential storage rocks for oil and natural gas. The Cruziana -Ichnostratigraphie allows a rough relative age classification at least for the older, fully marine, body-fossil-poor strata of these sequences, which facilitates the exploration of the geological conditions in these sedimentary basins. Due to the geographical isolation of the northern continents Laurentia ("Paleo-North America"), Baltica ("Paleo-Europe") and Sibiria ("Paleo-Central Siberia") in the early Paleozoic, the scope of this scheme is on Gondwana (South America, Africa, India, Australia) and Perigondwean terranos (such as Avalonia or South China). However, the relative dating of sedimentary rocks with the help of Cruziana also seems possible for Baltica, at least in the Upper Cambrian and Lower Ordovician.
The suitability of Cruziana as a key fossil is based on the relatively high diversity of the striation patterns on the praises of the tracks, which allows a distinction to be made between numerous Cruziana chnospecies or even subspecies, each of which only occurs in a relatively short stratigraphic interval. Since the stripe patterns are considered to be the “fingerprinting” of the trace producers, there is a relatively close correlation between the stratigraphic sequence of the Ichnospecies and the evolutionary change in the anatomy of the producers. Consequently, the Cruziana -Ichnostratigraphie is a kind of "surrogate biostratigraphy". A similarly close connection between the emergence and extinction of species in the course of development history and the change in the tradition of traces exists in tetrapods and their fossil tracks (see also tracking sandstone ). A major weakness of the scheme is that many of the Cruziana species it contains are only known from a single locality.
The table below shows the current version of the Cruziana Ichnostratigraphy. It should be noted that, as is now generally practiced by Seilacher, cruziana-like and rusophyciform traces with identical “fingerprints” are combined in the same Ichnospecies. Ichnospecies that occur in more than one locality are marked with an asterisk.
| Carbon | |
|---|---|
| Lower carbon | Upper carbon |
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| Devon | ||
|---|---|---|
| Lower Devon | Middle Devon | Upper Devonian |
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| Silurian | |
|---|---|
| Untersilur | Obersilur |
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| Ordovician | |
|---|---|
| Lower Ordovician | Upper Ordovician |
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| Cambrian | ||
|---|---|---|
| Lower Cambrian | Central Cambrian | Upper Cambrian |
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Web links
Individual evidence
- ↑ Sven O. Egenhoff, Bernd Weber, Oliver Lehnert, Jörg Maletz: Biostratigraphic precision of the Cruziana rugosa group: a study from the Ordovician succession of southern and central Bolivia. Geological Magazine. Vol. 144, No. 2, 2007, pp. 289-303, doi: 10.1017 / S0016756807003093 .
- ↑ a b c Alcide Dessalines d'Orbigny: Voyage dans l'Amerique méridionale (le Brésil, la République orientale de l'Uruguay, la République Argentine, la Patagonie, la République du Chili, la République de Bolivia, la République du Pérou) , exécuté pendant les années 1826, 1827, 1828, 1829, 1830, 1831, 1832, et 1833. Volume 3, Part 4, Paris / Strasbourg 1842, p. 30 ( archive.org ).
- ↑ a b c G. Winston Sinclair: The Generic Name Bilobites. In: Journal of Paleontology . Vol. 25, No. 2, 1951, pp. 228-231, JSTOR 1299805 .
- ^ A b Olev Vinn: Cruziana traces from the Late Silurian (Pridoli) carbonate shelf of Saaremaa, Estonia . In: Estonian Journal of Earth Sciences . Vol. 63, No. 2, 2014, pp. 71-75, doi: 10.3176 / earth.2014.06 .
- ↑ a b c d D. Christopher A. Stanley, Ron K. Pickerill: Systematic Ichnology of the Late Ordovician Georgian Bay Formation of Southern Ontario, eastern Canada . In: Royal Ontario Museum Life Sciences Contributions . Vol. 162, 1994, doi: 10.5962 / bhl.title.53483 , p. 10 ff.
- Jump up ↑ Guillermo F. Aceñolaza, Juan Pablo Milana: Remarkable Cruziana beds in the Lower Ordovician of the Cordillera Oriental, NW Argentina . In: Ameghiniana . Vol. 42, No. 3, 2005, scielo.org .
- ↑ a b c d e f Adolf Seilacher: Trilobite Burrows. In: Trace Fossils Analysis. Springer-Verlag, Berlin / Heidelberg 2007, ISBN 978-3-540-47225-4 , p. 31 ff.
- ^ RA Fortey, A. Seilacher: The trace fossil Cruziana semiplicata and the trilobite that made it . In: Lethaia . Vol. 30, No. 2, 1997, pp. 105-112, doi: 10.1111 / j.1502-3931.1997.tb00450.x .
- ^ A b Nicholas J. Minter, Spencer G. Lucas: The arthropod trace fossil Cruziana and associated ichnotaxa from the lower Permian Abo Formation, Socorro County, New Mexico. In: Virgil Lueth, Spencer G. Lucas, Richard M. Chamberlin (Eds.): Geology of the Chupadera Mesa. New Mexico Geological Society Fall Field Conference Guidebook. Vol. 60, 2009, pp. 291-298 ( PDF 8.80 MB).
- ^ A b John-Paul Zonneveld, S. George Pemberton, Thomas DA Saunders, Ronald K. Pickerill: Large, Robust Cruziana from the Middle Triassic of Northeastern British Columbia: Ethologic, Biostratigraphic, and Paleobiologic Significance . In: PALAIOS . Vol. 175, No. 5, 2002, pp. 435-448, doi : 10.1669 / 0883-1351 (2002) 017 <0435: LRCFTM> 2.0.CO; 2 JSTOR 3515719 .
- ^ A b c Richard G. Bromley, Ulla Asgaard: Triassic freshwater ichnocoenoses from Carlsberg Fjord, East Greenland . In: Palaeogeography, Palaeoclimatology, Palaeoecology . Vol. 28, 1979, pp. 39-80, doi : 10.1016 / 0031-0182 (79) 90112-3 .
- ↑ Grzegorz Sadlok: New data on the trace fossil, Cruziana semiplicata (Furongian, Wiśniówka Sandstone Formation, Poland): origin, ethology and producer . In: Annales Societatis Geologorum Poloniae . Vol. 84, 2014, pp 35-50, asgp.pl .
- ↑ M. Gabriela Mangano, Luis A. Buatois: Rusophycus leif erik soni Bergströn en la Formación Campanario implicancias en la de paleoecología Plains mareales cámbricas. Asociación Paleontológica Argentina, Publicación Especial. Vol. 9 (IV Reunión Argentina de Icnología y II Reunión de Icnología del Mercosur), 2003, pp. 65-84 ( apaleontologica.org.ar ).
- ^ Richard G. Bromley: Trace Fossils: Biology, Taphonomy, and Applications. Springer, Berlin / Heidelberg 1999, ISBN 978-3-540-62944-3 , p. 178
- ↑ James Hall: Paleontology of New York. Volume 2. Containing Descriptions of the Organic Remains of the Lower Middle Division of the New York System (Equivalent in Part to the Middle Silurian Rocks of Europe). C. van Benthuysen, Albany NY 1852, p. 23 ( archive.org )
- ^ A b G. Gand, J. Garric, J. Schneider, H. Walter, J. Lapeyrie, C. Martin, A. Thiery: Notostraca trackways in Permian playa environments of the Lodève basin (France) . In: Journal of Iberian Geology . Vol. 34, No. 1, 2008, pp. 73-108 ( online )
- ^ NH Trewin, MF Thirlwall: Old Red Sandstone. In: Nigel H. Trewin (Ed.): The Geology of Scotland. 4th edition. The Geological Society, London 2002, ISBN 1-86239-105-X , pp. 228, 236
- ↑ Luis A. Buatois, M. Gabriela Mangano: Trace fossils from a carboniferous turbiditic lake: Implications for the recognition of additional nonmarine ichnofacies . In: Ichnos . Vol. 2, No. 3, 1993, pp. 237-258, doi: 10.1080 / 10420949309380098 (alternative full text access : Researchgate ).
- ↑ Martin F. Glaessner: Palaeozoic arthropod trails from Australia . In: Paleontological Journal . Vol. 31, No. 1-2, 1957, pp. 103-108, doi: 10.1007 / BF02988968 .
- ↑ JE Pollard: Isopodichnus , related arthropod trace fossils and notostracans from Triassic fluvial sediments . In: Transactions of the Royal Society of Edinburgh: Earth Sciences . Vol. 76, No. 2-3, 1985, pp. 273-285, doi: 10.1017 / S026359330001049X
- ↑ David L. Fillmore, Michael J. Szajna, Spencer G. Lucas, Brian W. Hartline, Edward L. Simpson: Ichnology of a Late Triassic Lake Margin: The Lockatong Formation, Newark Basin, Pennsylvania. New Mexico Museum of Natural History Bulletin 76. Albuquerque 2017 ( GoogleBooks ; a smaller but significantly worse version is available from New Mexico Digial Collections ), pp. 18, 39 f.
- ↑ Ron K. Pickerill: Deep-water marine Rusophycus and Cruziana from the Ordovician Lotbinière Formation of Quebec . In: Atlantic Geology . . Vol. 31, No. 2, 1995, pp 103-108, hil.unb.ca .
- ↑ a b c Adolf Seilacher: Cruziana Stratigraphy. In: Trace Fossils Analysis. Springer-Verlag, Berlin / Heidelberg 2007, ISBN 978-3-540-47225-4 , pp. 187 ff.
- ↑ Dirk Knaust: Cambro-Ordovician trace fossils from the SW-Norwegian Caledonides . In: Geological Journal . Vol. 39, No. 1, 2004, pp. 1-24, doi: 10.1002 / gj.941 .