Carl Alwmark
Universitetslektor
Soft-tissue evidence for homeothermy and crypsis in a Jurassic ichthyosaur
Författare
Summary, in English
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.
Avdelning/ar
- Berggrundsgeologi
- MAX IV-laboratoriet
- Syngruppen
- Centrum för analys och syntes
- Kemisk fysik
Publiceringsår
2018
Språk
Engelska
Sidor
359-365
Publikation/Tidskrift/Serie
Nature
Volym
564
Issue
7736
Fulltext
Dokumenttyp
Artikel i tidskrift
Förlag
Nature Publishing Group
Ämne
- Geology
Aktiv
Published
Forskningsgrupp
- Lund Vision Group
ISBN/ISSN/Övrigt
- ISSN: 0028-0836