Ichthyosaurus
| Ichthyosaurus | ||||||||||||
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Fossil of Ichthyosaurus breviceps |
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| Temporal occurrence | ||||||||||||
| Lower Jurassic ( Hettangian to Sinemurian ) | ||||||||||||
| 201.3 to 190.8 million years | ||||||||||||
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| Scientific name | ||||||||||||
| Ichthyosaurus | ||||||||||||
| De la Beche & Conybeare , 1821 | ||||||||||||
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Ichthyosaurus ( Greek : ιχθυς / ichthys = "fish" and σαυρος / sauros = "lizard") is an extinct genus from the group of ichthyosaurs . Fossils are dated to the Lower Jurassic ( Hettangian to Sinemurian ) and have been found in Europe ( Belgium , England , Switzerland and Germany ). It is one of the best known ichthyosaurs and at the same time the eponymous genus of this group. The holotype of Ichthyosaurus was one of the best preserved fossils of the 19th century. He was discovered by Mary Anning in England.
Joseph Victor von Scheffel's poem Der Ichthyosaurus described its extinction in the Cretaceous period in humorous verses. The poem has been artistically immortalized on the Hohentwiel castle ruins by the sculptor Reinhard Siecke.
“ I suspect a world catastrophe;
It can't go on like this any longer!
What will become of the Lias still be,
if such things happen? "
The poem was set to music by Vinzenz Lachner in his cycle "Scherz im Ernst and Ernst im Scherz" op. 33.
description
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Live reconstruction of Ichthyosaurus communis
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Ichthyosaurus compared to a human
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Ichthyosaurus was smaller than other ichthyosaurs. Most of the specimens only reached a length of two meters. The largest known specimen was 3.30 meters long. Hundreds of well-preserved skeletons of Ichthyosaurus were found in the Jurassic rocks in Holzmaden in Germany . The joints of some bones were still flexible. Embryos were also discovered in the bellies of some specimens, indicating that Ichthyosaurus was viviparous. Similar fossils have also been found in Stenopterygius . The German finds of Ichthyosaurus , of which skin outlines are also known, prove that it had a fleshy dorsal fin and a large caudal fin.
Paleobiology
Ichthyosaurus' ear bones were solidly built, and they probably served to transmit vibrations from the water to the inner ear . However, in addition to hearing, sight was also important in order to hunt; the orbit was therefore protected by ossified "shields". Coprolites of Ichthyosaurus prove that he is of fish and squid malnourished.
It was previously thought that Ichthyosaurus laid eggs on land, but fossils show that it was viviparous. The animals were completely adapted to life in the water. At birth, the pups were likely born tail first to keep them from drowning.
Systematics
Ichthyosaurus was a basic representative of the Thunnosauria , a subgroup of the ichthyosaurs . Stenopterygius and the Ophtalmosauridae , which include Ophthalmosaurus and Platypterygius , are considered close relatives . The following is an example cladogram according to Patrick S. Druckermiller and Erin E. Maxwell (2010):
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Individual evidence
- ↑ Dean R. Lomax, Judy A. Massare: A new species of Ichthyosaurus from the Lower Jurassic of West Dorset, England, UK Journal of Vertebrate Paleontology, 2015, doi: 10.1080 / 02724634.2014.903260 .
- ^ Michael W. Maisch, Andreas T. Matzke: The Ichthyosauria (= Stuttgart contributions to natural history. Series B: Geology and Paleontology. Vol. 298, ISSN 0341-0153 ). State Museum for Natural History, Stuttgart 2000, (digitized PDF; 2.09 MB) .
- ↑ Christopher McGowan, Ryosuke Motani: Ichthyopterygia (= Handbook of Paleoherpetology. Part 8). Publishing house Dr. Friedrich Pfeil, Munich 2003, ISBN 3-89937-007-4 .
- ↑ Michael W. Maisch, Achim G. Reisdorf, Rudolf Schlatter, Andreas Wetzel: A large skull of Ichthyosaurus (Reptilia: Ichthyosauria) from the Lower Sinemurian (Lower Jurassic) of Frick (NW Switzerland). In: Swiss Journal of Geosciences. Vol. 101, No. 3, 2008, pp. 617-627, ISSN 1661-8726 .
- ↑ Robert Jurmain, Lynn Kilgore, Wenda Trevathan: Essentials of Physical Anthropology. Thomson / Wadsworth, Belmont, CA 2006, ISBN 0-495-03061-9 .
- ↑ Siecke's catalog of works . (PDF; 7.7 MB).
- ↑ Serious Joke and Serious Joke, Op.33 (Lachner, Vinzenz) - IMSLP. Retrieved July 29, 2020 .
- ↑ n the spring moon night: settings of poems about Maximilian II by Emanuel Geibel and members of the Munich poet circle ( The Crocodiles ); Martin Bruns and Christoph Hammer (piano), Verlag Annette Schumacher, Ratingen, 2008
- ^ Dean R. Lomax, Sven Sachs: On the largest Ichthyosaurus : A new specimen of Ichthyosaurus somersetensis containing an embryo. In: Acta Palaeontologica Polonica Vol. 62 (3), pp. 575-584, 2017, doi: 10.4202 / app.00376.2017.
- ↑ a b Ronald Böttcher: New findings on the reproductive biology of the ichthyosaurs (Reptilia) = New information on the reproductive biology of ichthyosaurs (= Stuttgart contributions to natural history. Series B: Geology and Palaeontology. Vol. 164). State Museum for Natural History, Stuttgart 1990, digitized .
- ↑ David M. Martill: Soupy substrate: A medium for the Preservation of Exceptional Ichthyosaurs of the Posidonia Shale (Lower Jurassic) of Germany. In: Kaupia. Darmstadt contributions to natural history. Vol. 2, 1993, ISSN 0941-8482 , pp. 77-97.
- ^ Douglas Palmer: The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. Marshall Publishing, London 1999, ISBN 1-84028-152-9 , p. 80.
- ↑ Patrick S. Druckermiller, Erin E. Maxwell: A new Lower Cretaceous (lower Albian) ichthyosaur genus from the Clearwater Formation, Alberta, Canada. In: Canadian Journal of Earth Sciences. Vol. 47, No. 8, 2010, ISSN 0008-4077 , pp. 1037-1053, doi: 10.1139 / E10-028 .
