évolution

Rates of skeletal character evolution in the skull and postcranial skeleton of hadrosauroids. Cladograms illustrate the results from branch likelihood tests for two morphological partitions: skull (cranium and mandible) (A) and postcranial skeleton (B). In both cladograms, results from the branch likelihood tests are summarized on a strict consensus tree derived from four separately analyzed MPTs, each with 100 dating replicates (a total of 400 Hedman-dated phylogenies). Pie charts on branches illustrate the proportion of dating replicates that showed significantly high rates (red), slow rates (blue), or nonsignificant average rates (white). No pie charts are plotted on branches that showed nonsignificant rates in 100% of dating replicates. Branches that showed high rates (red) in more than 50% of dating replicates are doubled in length. See the Supplementary Material for Hedman-based results plotted separately for each MPT (Supplementary Fig. S2) and for results using the MBL dating method (Supplementary Fig. S3). Silhouettes were created by Scott Hartman and were downloaded from http://phylopic.org (Creative Commons license CC BY 3.0).

Phylogenetic affinities of Saltriovenator and evolution of the hand in Theropoda. Reduced strict consensus of the shortest trees found by the phylogenetic analysis after pruning of Lewisuchus and Teleocrater. Numbers at nodes indicate decay index. Inferred manual phalangeal formula for selected nodes indicated below clade names. Hands of representative members of the avian stem (bold names) in extensor view (Herrerasaurus in flexor view), medial side at left, missing elements in white based on ancestral states inferred at least inclusive node containing the taxon. Red star indicates loss of metacarpal V, blue stars indicate multiple independent losses of metacarpal IV among tetanurans. Drawings by A. Cau.

Tylosaurus reconstruction. From Osborn, H. F. (1917). The origin and evolution of life, on the theory of action, reaction and interaction of energy.