Soft-tissue evidence for homeothermy and crypsis in a Jurassic ichthyosaur
Artikel i vetenskaplig tidskrift, 2018

Ichthyosaurs are extinct marine reptiles that display a notable external similarity to modern toothed whales. Here we show that this resemblance is more than skin deep. We apply a multidisciplinary experimental approach to characterize the cellular and molecular composition of integumental tissues in an exceptionally preserved specimen of the Early Jurassic ichthyosaur Stenopterygius. Our analyses recovered still-flexible remnants of the original scaleless skin, which comprises morphologically distinct epidermal and dermal layers. These are underlain by insulating blubber that would have augmented streamlining, buoyancy and homeothermy. Additionally, we identify endogenous proteinaceous and lipid constituents, together with keratinocytes and branched melanophores that contain eumelanin pigment. Distributional variation of melanophores across the body suggests countershading, possibly enhanced by physiological adjustments of colour to enable photoprotection, concealment and/or thermoregulation. Convergence of ichthyosaurs with extant marine amniotes thus extends to the ultrastructural and molecular levels, reflecting the omnipresent constraints of their shared adaptation to pelagic life.

Författare

Johan Lindgren

Lunds universitet

Peter Sjövall

RISE Research Institutes of Sweden

Volker Thiel

Georg-August-Universität Göttingen

Wenxia Zheng

North Carolina State University

Shosuke Ito

Fujita Health University

Kazumasa Wakamatsu

Fujita Health University

Rolf Hauff

Urwelt-Museum Hauff

Benjamin P. Kear

Uppsala universitet

Anders Engdahl

Lunds universitet

Carl Alwmark

Lunds universitet

Mats E. Eriksson

Lunds universitet

M. Jarenmark

Lunds universitet

Sven Sachs

Naturkundemuseum Bielefeld

Per E. Ahlberg

Uppsala universitet

Federica Marone

Paul Scherrer Institut

Takeo Kuriyama

Wildlife Management Research Center

University of Hyogo

Ola Gustafsson

Lunds universitet

Per Malmberg

Chalmers, Kemi och kemiteknik, Kemi och biokemi

Aurélien Thomen

Göteborgs universitet

Irene Rodríguez-Meizoso

Lunds universitet

P. Uvdal

Lunds universitet

Makoto Ojika

Nagoya University

Mary H. Schweitzer

Lunds universitet

North Carolina State University

North Carolina Museum of Natural Sciences

Nature

0028-0836 (ISSN) 1476-4687 (eISSN)

Vol. 564 7736 359-365

Ämneskategorier

Evolutionsbiologi

Annan geovetenskap och miljövetenskap

Zoologi

Infrastruktur

Chalmers infrastruktur för masspektrometri

DOI

10.1038/s41586-018-0775-x

PubMed

30518862

Mer information

Senast uppdaterat

2019-01-24