Fig. 2: Centre-of-mass evolution in bird-line archosaurs.
From: Decoupling body shape and mass distribution in birds and their dinosaurian ancestors
a Individual taxon normalised CoM positions (distance cranial and ventral to hip/body mass0.33) measured in extant birds and non-avian sauropsids, and predicted positions in extinct archosaurs based on skeleton:skin volume ratios and allometric equations from extant taxa. b CoM phylomorphospace plot of the 50 studied taxa, with extinct taxa represented as squares, and extant taxa (and surviving nodes) as circles. The larger yellow circles represent the major reconstructed nodes through avian evolution, and are numbered as followed, 1. Sauropsida, 2. Archosauria, 3. Dinosauria, 4. Saurischia, 5. Theropoda, 6. Neotheropoda, 7. Dilophosaurus + Neotetanurae, 8. Neotetanurae, 9. Coelurosauria, 10. Maniraptoriformes, 11. Pennaraptora, 12. Eumaniraptora, 13. Avialae, 14. Ornithuromorpha, 15. Neornithes, 16. Palaeognathae, 17. Neognathae, 18. Galloanserae. c Inset of the main plot (b) showing the overlapping CC_CoM confident intervals of the Theropoda node and those of the extant HLD bird node with the most caudal CoM position. d Inset of the main plot (b) showing the overlapping confidence intervals demonstrating that Avialae is first bird-line node to lie exclusively with extant FLD CoM morphospace. Green data points and lines represent extant non-avian sauropsids, black data points and lines are extinct non-avian sauropsids, red data points and lines represent hindlimb dominated birds, and blue data points and lines are forelimb dominated birds. Silhouettes of Microraptor, Tyrannosaurus and the ornithomimid by Matthew Dempsey, used with permission and without modification. Silhouettes of Coelophysis (CC BY 3.0; https://creativecommons.org/licenses/by/3.0/) and Herrerasaurus (CC BY 3.0; https://creativecommons.org/licenses/by/3.0/) by Scott Hartman sourced without modification from www.phylopic.org. Source data are provided as a Source Data file.
