The rise of pelagic sharks and adaptive evolution of pectoral fin morphology during the Cretaceous

• DOI: 10.1016/j.cub.2024.05.016
• Publication Date: 2024-06-03T14:38:07Z
• Authors: Phillip C. Sternes; Lars Schmitz; Timothy E. Higham
• Keywords: Chondrichthyes; Actinopterygii; Fish fin; Elasmobranchii

The emergence and subsequent evolution of pectoral fins is a key point in vertebrate evolution, as are dominant control surfaces for locomotion extant fishes.1Coates M. paired fins.Theory Biosci. 2003; 122: 266-287Crossref Scopus (91) Google Scholar,2Webb P.W. Locomotor patterns the Actinopterygian fishes.Am. Zool. 1982; 22: 329-342Crossref (224) Scholar,3Fish F.E. Lauder G.V. Control aquatic vertebrates: active passive design function.J. Exp. Biol. 2017; 220: 4351-4363Crossref PubMed (58) Scholar However, major gaps remain our understanding diversity among cartilaginous fishes (Chondrichthyes), group with an evolutionary history spanning over 400 million years current selachians (modern sharks) appearing about 200 ago.4Compagno L.J.V. Alternative life-history strategies time space.Environ. Fishes. 1990; 28: 33-75Crossref (294) Scholar,5Grogan E.D. Lund R. Greenfest-Allen E. origin early relationships chondrichthyans.in: Carrier J.C. Musick J.A. Heithaus M.R. Biology Sharks Their Relatives. Second Edition. CRC Press, 2012: 3-30Crossref Scholar,6Maisey J.G. What 'elasmobranch'? impact paleontology elasmobranch phylogeny evolution.J. Fish. 2012; 80: 918-951Crossref (0) Modern sharks charismatic vertebrates often thought to be predators roaming open ocean coastal areas, but most species occupy seafloor.4Compagno Here we use integrative approach understand what facilitated expansion pelagic realm morphological changes accompanied this shift. On basis comparative analyses framework time-calibrated molecular phylogeny,7Stein R.W. Mull C.G. Kuhn T.S. Aschliman N.C. Davidson L.N.K. Joy J.B. Smith G.J. Dulvy N.K. Mooers A.O. Global priorities conserving sharks, rays chimaeras.Nat. Ecol. Evol. 2018; 2: 288-298Crossref (185) show that modern expanded no later than Early Cretaceous (Barremian). pattern fin aspect ratios across congruent adaptive identify increase subclade disparity ratio at when sea surface temperatures were their highest.8Scotese C.R. Song H. Mills B.J. van der Meer D.G. Phanerozoic paleotemperatures: earth's changing climate during last 540 years.Earth Sci. Rev. 2021; 215103503Crossref (271) habitats likely involved extended bouts sustained fast swimming, which led selection efficient movement via higher fins. Swimming performance was enhanced due elevated sea, highlighting shark has been greatly impacted by change.