SUPPLEMENTAL DATA S4 List of characters used in disparity analysis 1. Relative anteroposterior width of the radius and ulna: (0) radius wider than the ulna; (1) nearly equal; (2) ulna wider than the radius (For an element to be considered wider than another it must exceed at least 10% the anteroposterior length of the smallest, otherwise, they will be considered equal). 2. Radius proportions (length/width): (0) 0.7>; (1) 0.7<. 3. Ulna proportions (length/width): (0) 0.7>; (1) 0.7<. 4. Preaxial accessory element: (0) absent; (1) present but not contacting the humerus; (2) present contacting the humerus. 5. Preaxial accessory element shape: (0) teardrop; (1) rounded/squared. 6. Preaxial accessory element proportions: (0) 1.3>; (1) 1.3<. 7. Intermedium proportions (length/width): (0) 0.7>; (1) 0.7<. 8. Intermedium proximal edge: (0) pointed; (1) flat. 9. Intermedium distal edge: (0) pointed; (1) flat. 10. Postaxial accessory element: (0) absent; (1) present but not contacting the humerus; (2) present contacting the humerus. 11. Number of digits directly supported by the intermedium: (0) one; (1) two 12. Intermedium-humerus contact: (0) intermedium does not contact the humerus and places distally to the radius and ulna; (1) intermedium is settled between radius and ulna and contacting the humerus. Table S4. Specimens sampled for PCA Taxon/Specimen Percentage of Time-bin coding in the distance matrix Arthropterygius 91.6 Oxfordian and chrisorum Kimmeridgian Ophthalmosaurus 100 Aalenian- icenicus Callovian, Oxfordian, Kimmeridgian and Tithonian MLP- 92-III-2-1 91.6 Aalenian- Callovian Palvennia 100 Tithonian hoybergeti Baptanodon natans 91.6 Oxfordian Arthropterygius 83.3 Tithonian thalassonotus Janusaurus lundi 91.6 Tithonian Undorosaurus 75 Tithonian gorodischensis Acamptonectes 25 Berriasian-early densus Aptian Gengasaurus 75 Kimmeridgian nicosiai and Tithonian Sumpalla argentina 100 Tithonian Cryopterygius 100 Tithonian kielanae Sveltonectes 83.3 Berriasian-early insolitus Aptian Cryopterygius 100 Tithonian kristiansenae Brachypterygius 100 Kimmeridgian extremus and Tithoninan Keilhauia 50 Tithonian and Berriasian-early Aptian “Platypterygius” 100 early Aptian- australis Cenomanian “Platypterygius” 83.3 Berriasian-early sachicarum Aptian “Platypterygius” 83.3 early Aptian- americanus Cenomanian “Platypterygius” 100 early Aptian- hercynicus Cenomanian Undorosaurus 100 Tithonian nessovi Caypullisaurus 91.6 Tithonian and bonapartei Berriasian-early Aptian Maiaspondylus 41.6 early Aptian- lindoei Cenomanian Grendelius 100 Tithonian alekseevi Aegirosaurus 100 Tithonian leptospondylus .