Souvrství Ferris

Tyrannosaurus rex, jeden z dinosaurů, jejichž fosilie byly objeveny v sedimentech souvrství Ferris.

Geologické souvrství Ferris zahrnuje sedimenty z období nejpozdnější křídy a nejmladšího kenozoika (paleocénu) na území západu Spojených států amerických (stát Wyoming). Usazeniny tohoto souvrství vznikaly v době asi před 66 až 63 miliony let, tedy od úplného konce křídové periody (geologický stupeň pozdní maastricht) až po začátek paleogénu.[1]

Charakteristika

Souvrství bylo poprvé definováno geologem C. F. Bowenem roku 1918, kdy byla také ustavena jeho typová lokalita.[2] Mocnost sedimentů tohoto souvrství dosahuje asi 600 až 2000 metrů. Nejčastějším typem horniny je zde jílovec a pískovec.[3] Kromě fosilií dinosaurů zde byly objeveny také početné sladkovodní zkameněliny ryb, obojživelníků, nedinosauřích plazů (želv, ještěrů a krokodýlovitých plazů) a četných savců.[4] Početné jsou také palynomorfy (fosilní pylová zrna), která poukazují na značnou druhovou pestrost tehdejší flóry.[5]

Přítomné rody dinosaurů

Ankylosaurus - jeden z dinosaurů, objevených v sedimentech souvrství Ferris.

Teropodi

Ankylosauři

Marginocefalové

Ornitopodi

Odkazy

Reference

  1. ↑ Wroblewski, Anton F. (1995). First report of changes in lower vertebrate faunas across the Cretaceous-Tertiary boundary, western Hanna Basin, Wyoming: Journal of Vertebrate Paleontology. Supp. to volume 15, p. 61A.
  2. ↑ Bowen, C. F. (1918). Stratigraphy of the Hanna basin, Wyoming. IN Shorter contributions to general geology, 1917: U.S. Geological Survey Professional Paper, 108-L, p. L227-L235.
  3. ↑ Gill, J. R.; Merewether, E. A.; Cobban, W. A. (1970). Stratigraphy and nomenclature of some Upper Cretaceous and lower Tertiary rocks in south-central Wyoming: U.S. Geological Survey Professional Paper, 667, 53 p.
  4. ↑ Eberle, J. J. and Lillegraven, J. A. (1998). A new important record of earliest Cenozoic mammalian history: geologic setting, Multituberculata, and Peradectia. Rocky Mountain Geology, 33(1): 3-47.
  5. ↑ Perry, W. J., Jr.; and Flores, R. M. (1997). Sequential Laramide deformation and Paleocene depositional patterns in deep gas-prone basins of the Rocky Mountain region, IN Dyman, T. S., ed., Geologic controls of deep natural gas resources in the United States: U.S. Geological Survey Bulletin, 2146, p. 49-59.
  6. ↑ SOCHA, Vladimír. Byl T. rex asijským imigrantem?. OSEL.cz [online]. 23. března 2017. Dostupné online.  (česky)
  7. ↑ https://www.osel.cz/9556-moloch-od-reky-styx.html
  8. ↑ https://dinosaurusblog.com/2019/05/06/thescelosaurus-mozna-hrabal-nory/

Literatura

  • Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd Edition. Berkeley: University of California Press. 861 pp. ISBN 0-520-24209-2.

Externí odkazy

Média použitá na této stránce

Ankylosaurus magniventris reconstruction.png
Autor: Emily Willoughby (e.deinonychus@gmail.com, http://emilywilloughby.com), Licence: CC BY-SA 3.0
Simple drawing of Ankylosaurus magniventris, a North American Cretaceous ankylosaurid. Based on skeletal reconstruction in Paul 2010.
Tyrannosaurus-rex-Profile-steveoc86.png
Autor: Steveoc 86, Licence: CC BY-SA 4.0
A life restoration of the theropod dinosaur Tyrannosaurus rex.


• The proportions are based on a Tyrannosaurus skeletal reconstruction by Scott Hartman [1]
• It's not clear whether derived tyrannosaurs would have been covered in scales, feathers, or a combanation of both. A few small skin impressions have been described for Tyrannosaurus which show small pebbled skin; close relatives, Tarbosaurus and Gorgosaurus are known to have similar pebbled skin.[1][2] Skin impressions from the closley related Gorgosaurus are reported to show both smooth, naked skin and scales.[3][4] A 2017 study looked at a variety of tyranosaurid skin impressions and came to the conclusion that derived tyrannosaurs were probably scaly over most their body. [2]
What complicates the issue is that most coelurosaur fossils show feathers covering thier bodies and inference would suggest the same for tyrannosaurs. The smaller basal tyrannosauriod Dilong and the larger tyrannosauroid Yutyrannus also preserve feather impressions. This raises the probability that, derived tyrannosaurs had a mix of feathers and scales on different parts of the body or that feathers were lost as individuals reach maturity [5][6]
A study published in 2017 looked at the texture of a tyrannosaurs skull bones and suggested that there may have been large, flat Crocodile-like skin cracks/scales on the front of the snout of tyrannosaurids. [7] The details on the head in this restoration are based on an similar interpetration of bone texture by Mark Witton in which he suggests that certain areas of the head were covered in a cornified sheath as well as scales. [2]

I often update my images. If you want to post any of my images on a website, if possible, don’t host/save it to the website server. I’d prefer it if the image's Wikimedia URL is used or a link is provided to this page. This allows updates to be seen by future viewers. Thanks.


References

  1. ↑ Currie, Philip; Badamgarav, Demchig; Koppelhus, Eva. (2003). "'The First Late Cretaceous Footprints from the Nemegt Locality in the Gobi of Mongolia'" (PDF). Ichnos 10 (1): 1-13.
  2. ↑ a b Bell, P R., et al (2017). "Tyrannosauroid integument reveals conflicting patterns of gigantism and feather evolution". Biology Letters. DOI:10.1098/rsbl.2017.0092.
  3. ↑ Currie, P. (2001). 2001 A. Watson Armour Symposium: The Paleobiology and Phylogenetics of Large Theropods. Field Museum of Natural History, Chicago.
  4. ↑ Carpenter, Kenneth (1997) "Tyrannosauridae" in Currie, Philip J. & Padian, Kevin (eds.). , ed. Encyclopedia of Dinosaurs, San Diego: Academic Press, pp. 768 ISBN: 0-12-226810-5.
  5. ↑ Xu, X., Norell, M. A., Kuang, X., Wang, X., Zhao, Q., Jia, C. (2004). "Basal tyrannosauroids from China and evidence for protofeathers in tyrannosauroids". Nature 431: 680–684. DOI:10.1038/nature02855.
  6. ↑ (2012). "A gigantic feathered dinosaur from the Lower Cretaceous of China" (PDF). Nature 484: 92–95. DOI:10.1038/nature10906. PMID 22481363.
  7. ↑ (2017). "A new tyrannosaur with evidence for anagenesis and crocodile-like facial sensory system". Scientific Reports 7: 44942. DOI:10.1038/srep44942.