Fig. 4 in The completeness of the fossil record of plesiosaurs, marine reptiles from the Mesozoic

Fig. 4. Changes in skeletal completeness through time. A. Plesiosaur SCM2 and ichthyosaur SCM2. B. Plesiosaur CCM2 and pterosaur CCM2. C. Plesiosaur CCM2 and Mesozoic bird CCM2. Silhouettes are from phylopic.org, and are credited to Adam Stuart Smith (Plesiosaurus), T. Michael Keesey (Archaeopteryx), and Gareth Monger (Pterodactylus, Ichthyosaurus). Abbreviations: CCM, character completeness metric; SCM, skeletal completeness metric (for detailed explanation of terms see Completeness metrics in Methods section).