Hematological convergence between Mesozoic marine reptiles (Sauropterygia) and extant aquatic amniotes elucidates diving adaptations in plesiosaurs

PeerJ

article

Corinna V. Fleischle¹  P. Martin Sander¹  Tanja Wintrich¹  Kai R. Caspar¹ 

[1] Section Paleontology, Institute of Geosciences, University of Bonn;Dinosaur Institute;Institute of Anatomy, University of Bonn;Department of General Zoology, Faculty of Biology, University of Duisburg-Essen

关键词: Plesiosauria;    Adaptive convergence;    Aquatic adaptation;    Sauropterygia;    Bone histology;    Erythrocytes;    Cell size;    Hematology;   

DOI  :  10.7717/peerj.8022

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Plesiosaurs are a prominent group of Mesozoic marine reptiles, belonging to the more inclusive clades Pistosauroidea and Sauropterygia. In the Middle Triassic, the early pistosauroid ancestors of plesiosaurs left their ancestral coastal habitats and increasingly adapted to a life in the open ocean. This ecological shift was accompanied by profound changes in locomotion, sensory ecology and metabolism. However, investigations of physiological adaptations on the cellular level related to the pelagic lifestyle are lacking so far. Using vascular canal diameter, derived from osteohistological thin-sections, we show that inferred red blood cell size significantly increases in pistosauroids compared to more basal sauropterygians. This change appears to have occurred in conjunction with the dispersal to open marine environments, with cell size remaining consistently large in plesiosaurs. Enlarged red blood cells likely represent an adaptation of plesiosaurs repeated deep dives in the pelagic habitat and mirror conditions found in extant marine mammals and birds. Our results emphasize physiological aspects of adaptive convergence among fossil and extant marine amniotes and add to our current understanding of plesiosaur evolution.

【 授权许可】

CC BY