Stenopterygius sp.

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Time: Early Jurassic (~180 million years ago)

Region: Baden-Württemberg, Germany

Formation: Posidonia Shale

Coloration Data

Ichthyosaur coloration has been investigated in several key studies. Initially, Lindgren et al. (2014) examined the tail fluke of an indeterminate ichthyosaur (specimen YORYM 1993.338). Based on this material and other fossils with complete soft-tissue outlines, the authors inferred that ichthyosaurs were uniformly dark-colored. However, a later and more detailed investigation by Lindgren et al. (2018) on specimen MH 432 (Stenopterygius sp.) revealed that pigmentation was differentially distributed, strongly indicating countershading (a dark dorsal surface and a pale ventral surface). Additionally, the researchers identified dendritic melanophores — cellular structures that in modern reptiles are responsible for physiological color change via pigment translocation.

Method: Integrated molecular and cellular analyses (including SEM, SRXTM, SRS-XRF, and ToF-SIMS).

Publications

• Johan Lindgren, Peter Sjövall, Ryan M. Carney, Per Uvdal, Johan A. Gren, Gareth Dyke, Bo Pagh Schultz, Matthew Shawkey, Kenneth R. Barnes, Michael J. Polcyn (2014)
  An article examining the coloration of an ichthyosaur, a mosasaur, and an Eocene sea turtle.
• Johan Lindgren, Peter Sjövall, Volker Thiel, Wenxia Zheng, Shosuke Ito, Kazumasa Wakamatsu, Rolf Hauff, Benjamin P. Kear, Anders Engdahl, Carl Alwmark, Mats E. Eriksson, Martin Jarenmark, Sven Sachs, Per E. Ahlberg, Federica Marone, Takeo Kuriyama, Ola Gustafsson, Per Malmberg, Aurélien Thomen, Irene Rodríguez-Meizoso, Per Uvdal, Makoto Ojika & Mary H. Schweitzer (2018)
  Research into the coloration of the ichthyosaur.
• Arindam Roy, Michael Pittman, Evan T. Saitta, Thomas G. Kaye, Xing Xu (2020)
  An overview article on the paleo‑coloration of amniotes.
• Jakob Vinther (2015)
  An overview of methods for reconstructing paleo‑coloration.

Documents and files

• Roy_et_al_2020.pdf (PDF)
  Review article on amniote paleocolor in Biological Reviews of the Cambridge Philosophical Society.
• Vinther_2015.pdf (PDF)
  Review article on fossil color reconstruction.
• Lindgren_et_al_2018.pdf (PDF)
  Study of specimen MH 432 of the ichthyosaur Stenopterygius sp.

Reconstructions

Fossils

Size comparison