Appendix S3 Taxon-character matrix used for phylogenetic analysis. 1 11 21 31 41 51 61 71 81 91 101 111 121 131 Outgroup 0?000000?0 0??00???00 000??000?0 00?0?00?00 0???0???00 ?0000000?0 00??000000 0?0?0000?0 00?000?000 0?00?0?00? 00000??000 0000000000 0000000000 ?0000 Carsosaurus marchesetti ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????0000? 0????0?0?? ??????0110 0000000000 000000001? ?00?0 Aigialosaurus 0?00?0?021 00??0???10 10?10?00?0 00???000?? ?1??0???1? ?0???00??? ?1??000?01 00?0000020 0?010?0000 0???000000 00000?00?0 0000?00000 000000001? ?0000 Haasiasaurus gittelmani ?????????? ?????????? ?????????? ?????????? ?11?020?00 ????????00 0010100000 000000001? 0??1000000 01000000?0 ???11101?1 00?0000000 01110000?? ?00?? Komensaurus carrolli ?????????? ?????????? ?????????? ?????????? ?20?0?1000 ?0???????? ????????00 00???????? ???1???0?0 01??00?0?0 0????????? ???????000 0?000?0011 ?0000 Halisaurus platyspondylus 1010000021 100000??10 101?0?00?? ???11????1 ?200101000 ?0001????? ??201?0001 0001000010 1??0?????? 00???????? 1????????? ?????????? ???????1?? ???00 Halisaurus sternbergi 0?100?0021 000000??00 10100000?? ??0210???0 020?1??000 ?0?01??0?1 ?1201?0?01 00010?0010 0?10??0010 00??001110 1011111110 0100100001 0111001111 ?0000 Dallasaurus turneri ???????0?? 0???1?10?? ?????????? ?????????0 ?????????? ?????????0 0020??001? ???100002? 0011??0010 11110???0? 1??00?010? ?01?00000? ?????000?? ?0?01 Clidastes liodontus 111000?020 010?101010 01111?10?1 0021002??1 010?000000 00010100(12)0 022?100010 00?1010020 1011000000 120101?111 1010110100 0210101112 1000101000 12001 Clidastes moorevillensis 1110000020 0100101010 01111?10?1 0021?020?1 010?001010 0001010020 0220100010 0001010020 1011000000 12?101?111 1??0110100 0210101112 1000101000 12001 Clidastes propython 111000?120 0100101010 0111??10?1 0021?0???1 010?001010 0001010010 02201?1010 0001010020 1011000000 12?10???1? 1???????00 0210101112 10?0?????? ?2?01 Ectenosaurs clidastoides 1110001020 0111102011 10001?00?0 1111011100 0100121101 110??00330 02001?0000 0010011020 1001001000 1???0????? ???0101110 021???0012 010100???? ?1031 Globidens alabamaensis ???????10? 1110101??? ??????10?1 0??1?????1 010?1111?0 ??010????? ??2010?110 0001100110 1011??0?0? 12??0????? ???????10? ?21010111? ?????????? ?2?01 Globidens dakotensis 1110?0?101 11??101010 01?11?11?1 01410020?1 010?101110 ?0(01)10100?? ?????????? ???1100110 1011?00?0? 12?10????? ?????????? ?????????? ?????????? ???01 Mosasasaurus conodon ?????????? ?????????? ?????????? ?????????? ?????????? ????????1? ?2201????0 0001010021 101110010? 12011????? 1???1?0101 031110111? 1????????? ?2?01 Mosasaurus maximus 111001?000 11??101110 02111?1100 0131??21?1 000?001001 ?110110030 022010?110 1101010021 1011101100 120?1??111 1??0210101 1311101112 1000111000 12101 Mosasaurus missouriensis 111001?100 01??101110 01?11?11?0 0?3100???1 000?001000 ?1(01)0110?30 02?0101110 110101002? 1011?0000? 120111?1?? 1??01??100 ?????????2 100?11???? ?2?01 Platecarpus planifrons 1010000001 011?100?11 10?11?00?? 115000?100 0210011000 ?0(01)1100250 0220010000 0010011020 110100000? 11??0????? ???0101110 020?1100?2 011100???? ?1?20 Platecarpus tympaniticus 0010000001 1111100?11 11011?0100 11500011?0 0211011100 10(01)1100351 ?221010000 0010010020 1100100000 1100000100 0100101110 020??1?012 0111001011 01030 Plesiotylosaurus crassidens 1110?0?110 11??101110 01?11?1111 00411????1 110?101110 ?0?11???20 02??101?10 0??1?0002? 1?????0000 12?10????? ???0110101 1312101112 100010???? ?2?0? Plioplatecarpus ???????001 1100100?11 13011?0100 01?0??1100 0211001200 ?0(01)1100351 ?221010000 0010010020 1??0??0000 110000???? 0??0101110 020?110012 011100???? ?1?30 Plotosaurus bensoni 101001?101 01??101110 11?11111?0 0111012001 000?001000 01(01)0110?10 1?2?1???10 110000012? ?010?10?01 12??1????? ?????????? ?????????? ?????????? ????? Plotosaurus tuckeri 1010?1?101 01??101110 11?11111?0 011101?0?1 000?001000 ?110110?10 12??111?10 1?0??????? 1????10101 120111???1 ???0210101 1311101112 100011???? ?2101 Prognathodon overtoni 101000?100 1100101110 01?11111?1 01500?20?1 110?101110 ??01010030 0210101110 0101100121 1??????0?? 12???????? 1????????? ?212101?1? ?????????? ???01 Prognathodon rapax 101000?100 0100101110 01111?11?1 ?041?020?1 110?101110 00011100?1 ?21010???0 0001100121 10110?0000 12110????? 1??01?0101 1212101112 100010???? ?2?01 Tylosaurus nepaeolicus 121111?001 010111??10 00?11101?0 0140???110 011?021011 1001001?40 1220000000 0000010021 100010000? 1100?????? ?????????? ?10?1?0001 ?11100???? ???00 Tylosaurus proriger 1211111001 11?111??10 01?1110110 ?141011100 000?021000 1001001040 1220001000 0000010021 1100?00000 1100001100 0101101110 110?110001 ?1110010?0 01100 Yaguarasaurus columbianus 0010?0?020 00???02012 00?11000?0 ?13001111? ?110021001 1000000131 ?????????? ???00?0010 0??1?????? ?????????? ?????????? ?????????? ?????????? ???20 Russellosaurus coheni 101??00020 0011102012 00011000?0 1120?11110 0110021001 1000000121 ?110010001 00100?0010 0????????? ?????????? ?????????? ?????????? ?????????? ???1? Angolasaurus bocagei 101??0?01? 11???0??11 00?1??00?0 ??50????1? ?210001100 1000100251 ?22?010001 00100?002? 0??1?????? ?????????? ?????????? ?????????? ?????????? ???30 Tethysaurus nopcsai 0010?0?021 10??102012 00?11000-0 ?100??11?? 0010021011 1?00000111 -110010001 00000?000- 0??10?0010 000????0?? 0??1000100 0?????011? ??????000? ????? Pannoniasaurus inexpectatus 0000000??? ?????????? ?????????0 1????????? ?110021011 0000????0? ?12010?001 0000000?11 0??10?0010 000????0?? 0????????? ??0001011? ??????00?? ?????