Palaeoniscum free life i
| Palaeoniscum free life i | ||||||||||||
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Palaeoniscum free life i |
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| Temporal occurrence | ||||||||||||
| 259 to 254 million years | ||||||||||||
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| Palaeoniscum free life i | ||||||||||||
| Blainville , 1818 | ||||||||||||
Palaeoniscum freilebeni , sometimes referred to in German as "copper slate herring", is a fossil, extinct species of bony fish that is found in the Zechstein of Europe (formation of the Permian , todaycountedas Wuchiapingium according to international terminology).
description
The species reached a body length of mostly 10 to 20 centimeters, individual specimens from 5 to 40 centimeters. Like many related species, it had an elongated body with a heterocerker caudal fin , which was covered by rhombic, rows of scales. These ganoid scales , or enamel scales , with a complex internal canal system, surface covered by small pores and dentine deposits, sat in the species between the supracleithum (a bone of the shoulder girdle) and the base of the caudal fin in 68 to 70 diagonal rows. They formed a reinforced skin armor, which is usually more striking and better preserved in the fossil than the actual skeleton. Occasionally it is fossilized by copper minerals. Characteristics of the species are: parietal (a skull bone) square, frontal very large and narrower at the back than at the front, with a clearly separated lateral process, the interfrontal suture curved. The gill cover large and twice as high as it is wide, without antoperculars, the suboperculars noticeably lower in front than behind. Branchiostegal rays (cf. Branchiostegal apparatus ) about ten or eleven. Upper jaw with a series of narrow, conical teeth. Lower jaw with two types of teeth of different sizes that are not widened like fangs. Rays of the pectoral fins branched from their base.
The species is difficult to distinguish from the sometimes very similar related species according to its habitus and external shape. Within the genus Palaeoniscum , numerous, often inadequately described species have been described , most of which have now been assigned to other genera. At times it served as a taxon in a drawer, in which numerous habitually similar types of unclear family relationships were sorted. Since the genus has not been revised for a long time , the delimitation to a number of similar species is uncertain.
history
Palaeoniscum has received the attention of collectors, naturalists and scientists for centuries, as the fossil fish were produced in large quantities during mining on copper slate in the horizontal line of the saline Zechstein series. It is therefore one of the earliest scientifically researched fossil fish species that has been described and illustrated again and again. Johann Carl Freileben , after whom the species was named, summarized the story in 1815: (pp. 154–155): “Petrifications: The copper slate has always attracted the attention of the people because of the fossilizations that occur so frequently in it (especially of fish) Naturalist on himself. Mineralogists of the sixteenth century, Mathesius , Agricola , Albinus, Kentmann , Valerius Cordus, and Spangenberg commemorate them; later from the seventeenth and eighteenth centuries especially Becher, Munster, Brunner (or Alberti), Irenäus , Stephani, Mylius, Büttner, Brückmann , Kräutermann , Scheuchzer , Leibnitz and Ritter . The fossils from the Hessian copper schists were primarily described by Wolfarth, as well as those from the Mansfeldian Zückert , Faupl and Meinicke; For the most complete news from the latter, we thank a former head of the Kupferkammerhütte near Hettstädt, Hoffmann. "
Other well-known naturalists who also describe the copper shale fish are missing from the list. Zückert describes the fish as perch (p. 200). Gmelin , the translator and editor of the works of Carl von Linné , who also published an illustration (panel VII, Fig. 90, Persch, near Eisleben), is of the same opinion .
Taxonomy
The original description by Blainville 1818 was based on specimens from the Mansfeld Revier in the Harz foreland, Blainville named it in honor of Johann Carl Freileben , Mining Commissioner of the Mansfeld mines and later Mining Captain of the State of Saxony. Louis Agassiz described the genre in the second volume of his monumental work "Recherches sur les Poissons Fossiles" under the name Palaeoniscus and changed the species name from the original spelling free life to free life . The species was then listed for a long time as Palaeoniscus freilebeni Agassiz in scientific literature. In 1917 David Starr Jordan changed the generic name (as a suspected misspelling) back to Palaeoniscum , but left the changed species name, this spelling is common today. The species can still be found in numerous publications under the name Palaeoniscus freilebeni, given by Agassiz .
Palaeoniscum freieslebeni belongs to the "lower" ray- or "Schmelzschuppern" of which only a few relic groups such as a heterogeneous group of mostly extinct and only fossil preserved fish, Knochenganoiden , sturgeon and bichirs up in recent survived time. Originally conceived as the order Ganoidei, it soon became clear that it was not a monophyletic group. Today the fossil representatives are often summarized in an order Palaeonisciformes , but their monophyly is also doubtful. Presumably it is not a closed community of descent (a clade ), but a "grade", a group of non-closely related core group representatives who have gradually become more and more similar to the modern representatives and are therefore differently closely related to them. Often they are therefore only understood as a form taxon (Palaeoniscoide or Palaeoniscimorph). If one follows the results, Palaeoniscum freilebeni is more closely related to the “modern” ray fins than to the cartilaginous organoids.
The ancestors of the genus moved from freshwater to marine saltwater habitats.
Finds
The species is one of the most common fish fossils in copper shale and is considered the key fossil of copper shale. It is the most common type of fish in all copper shale deposits; in the North Hessian Richelsdorf Mountains , around 90 percent of all fossil fish belong to this species. There are also extensive finds from the copper slate of the southern Harz near Osterode (during the construction of the Butterberg tunnel), near Walkenried, near Neustadt, Sangerhausen and in the Mansfeld Mulde in the eastern Harz in Eisleben and Mansfeld. Further finds come from corresponding deposits in the European Zechstein Basin, from Legnica (Liegnitz), Poland in the east to Durham , northern England, in the west. While most finds are of the copper shale type, other finds are rare. Noteworthy, for example, is a deliberately excavated outcrop in the TERRA.vita nature and geopark near Hasbergen near Osnabrück.
During the lifetime of the fish species, the Central European Permian Basin was a stagnant shallow sea. When they died, the fish living in the oxygen-containing surface layer sank into the oxygen-free and hydrogen sulfide-rich (anaerobic) bottom water, where they could not be used by scavengers. Hence the extremely good preservation of these fish.
In 2014 new finds of the species from Turkey were published. They were originally discovered during oil prospecting in the south-east of the country near Çukurca in the province of Hakkâri and have been researched in more detail since 2009. Here, too, the fossils lay in a black, fine-grained slate of a similar period.
Individual evidence
- ↑ Silvio Brandt (2012): Goldfish, silverfish and glittering spiny animals in the Zechstein. Fossils, Journal of Earth History, Special Issue 2012: 54-64. (Digitized version)
- ↑ a b Izzet Hoşgör & Stanislav Štamberg (2014): a first record of late Middle Permian actinopterygian fish from Anatolia, Turkey. Acta Geologica Polonica 64 (2): 147-159. doi: 10.2478 / agp-2014-0009
- ↑ a b Kathryn E. Mickle (2017): The lower actinopterygian fauna from the Lower Carboniferous Albert shale formation of New Brunswick, Canada - a review of previously described taxa and a description of a new genus and species. Fossil Record 20: 47-67. doi: 10.5194 / fr-20-47-2017 (open access)
- ^ Free life, Johann Carl (1815): Geognostic work, third volume (with 2 coppers). - Graz and Gerlach, Freyberg, 338 pp.
- ↑ Zückert, Johann Friedrich (1763): The natural history of some provinces of the Lower Harz together with an appendix from the Mansfeld copper schists. - Friedrich Nicolai, Berlin, 212 pp.
- ^ Gmelin, Johann Friedrich (1778): The knight Carl von Linné Royal Swedish personal physician etc. etc .; complete natural system of the mineral kingdom according to the twelfth Latin edition in a free and enlarged translation; Third part with twelve copper plates. - Gabriel Nicolaus Raspe, Nuremberg.
- ^ Blainville, H.-MD (1818). Sur les Ichthyolites, les Poisons Fossiles; Article extrait du Nouveau Dictionnaire d'Histoire Naturelle , vol. 28, Abel Lange, p. 16.
- ↑ Palaeoniscum freilebeni. Museum Schloss Bernburg, paleontological collection
- ^ BR Gardiner (1989): Interrelationships of lower actinopterygian fishes. Zoological Journal of the Linnean Society 97: 135-187.
- ↑ Lauren C. Sallan (2014): Major issues in the origins of ray-finned fish (Actinopterygii) biodiversity. Biological Reviews 89: 950-971. doi: 10.1111 / brv.12086
- ^ Carlo Romano, Martha B. Koot, Ilja Kogan, Arnaud Brayard, Alla V. Minikh, Winand Brinkmann, Hugo Bucher Jürgen Kriwet (2014): Permian – Triassic Osteichthyes (bony fishes): diversity dynamics and body size evolution. Biological Reviews 91 (1): 106-147. doi: 10.1111 / brv.12161
- ^ Günther Schaumberg (1977): The Richelsdorfer Kupferschiefer and his fossils, III. The Outcrop 28 (8/9): 297-352.
- ^ Cajus Godehard Diedrich (2009): A coelacanthid-rich site at Hasbergen (NW Germany): taphonomy and palaeoenvironment of a first systematic excavation in the Kupferschiefer (Upper Permian, Lopingian). Palaeobiodiversity and Palaeoenvironments 89: 67-94. doi: 10.1007 / s12549-009-0004-6