Tylosaurus nepaeolicus

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Time: Late Cretaceous (~85–80 million years ago)

Region: Kansas, USA

Formation: Niobrara Formation

Coloration Data

Within the fossilized scales of specimen SMU 76532, belonging to the mosasaur Tylosaurus nepaeolicus, structures morphologically consistent with melanosomes were discovered. Their chemical composition demonstrated a high-fidelity match with eumelanin — the pigment responsible for black and dark brown tones. Because the analysis was restricted to an isolated skin fragment, it is impossible to determine whether the animal was uniformly dark or possessed a lighter ventral surface indicative of countershading.

Method: Scanning electron microscopy (SEM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) for tissue chemical characterization.

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.

Reconstructions

Fossils

Size comparison