A New Elasmosaurid Plesiosaurian from the Early Cretaceous of Russia Marks an Early Attempt at Neck Elongation Supplementary

Home , Albertonectes, Aristonectes, Augustasaurus, Brachauchenius, Brancasaurus, Callawayasaurus

1 A new elasmosaurid plesiosaurian from the Early Cretaceous of

2 Russia marks an early attempt at neck elongation

4 Supplementary information

7 8 Supplementary tables

9 Table S1. Temporal data used to timescale the phylogenetic tree. See also supplementary file

10 “SUPP_ranges.txt”.

FAD LAD

Yunguisaurus_liae 242 237

Pistosaurus_postcranium 247.2 242

Pistosaurus_skull 247.2 242

Augustasaurus_hagdorni 247.2 242

Bobosaurus_forojuliensis 237 227

Macroplata_tenuiceps 201.3 199.3

Anningasaura_lymense 201.3 199.3

Stratesaurus_taylori 201.3 199.3

Avalonnectes_arturi 201.3 199.3

Eurycleidus_arcuatus 201.3 199.3

Meyerasaurus_victor 182.7 179.3

Maresaurus_coccai 170.3 168.3

Borealonectes_russelli 166.1 163.5

Rhomaleosaurus_megacephalus 201.3 199.3

Archaeonectrus_rostratus 201.3 199.3

Rhomaleosaurus_cramptoni 182.7 174.1

Rhomaleosaurus_zetlandicus 182.7 174.1

Rhomaleosaurus_thorntoni 182.7 174.1

Attenborosaurus_conybeari 199.3 190.8

Plesiosaurus_dolichodeirus 199.3 190.8

Eopleiosaurus_antiquior 201.3 199.3

Eretmosaurus_rugosus 199.3 190.8

Westphaliasaurus_simonsensii 190.8 182.7

Seelyosaurus_guilelmiimperatori 182.7 174.1 Microcleidus_tournemirensis 182.7 174.1

Microcleidus_brachypterygius 182.7 174.1

Microcleidus_homalospondylus 182.7 174.1

Plesiopterys_wildi 182.7 174.1

Cryptoclidus_eurymerus 166.1 163.5

Tricleidus_seeleyi 166.1 163.5

Muraenosaurus_leedsii 166.1 163.5

Kimmerosaurus_langhami 152.1 145

Pantosaurus_striatus 163.5 157.3

Picrocleidus_beloclis 166.1 163.5

Tatenectes_laramiensis 163.5 157.3

Plesiosaurus_mansellii 157.3 145

Colymbosaurus_trochanterius 157.3 145

Djupedallia_engeri 157.3 145

Spitrasaurus_spp 157.3 145

Abyssosaurus_nataliae 132.9 129.4

Umoonasaurus_demoscyllus 125 100.5

Nichollssaura_borealis 113 110.5

Leptocleidus_capensis 139.8 132.9

Leptocleidus_superstes 129.4 125

Hastanectes_valdensis 139.8 132.9

Vectocleidus_pastorum 129.4 125

Gronausaurus_wegneri 145 139.8

Brancasaurus_brancai 145 139.8

Nakonanectes_bradti 72.1 66

Speeton_Clay_Plesiosaurian 132.9 129.4

Wapuskanectes_betsynichollsae 113 107.8

Eromangasaurus_australis 105.5 100.5 Tuarangisaurus_keyesi 86.3 66

Styxosaurus_snowii 86.3 72.1

Styxosaurus_sp.Hydralm 86.3 72.1

Elasmosaurus_platyurus 86.3 72.1

Terminonatator_ponteixensis 86.3 72.1

Libonectes_morgani 93.9 89.8

Kaiwhekea_katiki 72.1 66

Aristonectes_quiriquinensis 72.1 66

Aristonectes_parvidens 83.6 66

Morturneria_seymourensis 72.1 66

Albertonectes_vanderveldei 86.3 72.1

Kawanectes_lafquenianum 86.3 66

Vegasaurus_molyi 72.1 66

Morenosaurus_stocki 72.1 66

Hydrotherosaurus_alexandrae 72.1 66

Aphrosaurus_furlongi 72.1 66

Zarafasaura_oceanis 72.1 66

Futabasaurus_suzukii 86.3 83.6

Callawayasaurus_colombiensis 125 121

MLP_99_XII_1_5 72.1 66

Thalassomedon_haningtoni 100.5 93.9

Alexandronectes_zealandiensis 72.1 66

LACM_2832__ 72.1 66

Cardiocorax_mukulu 72.1 66

Lagenanectes_richterae 132.9 129.4

Jucha_squalea 132.9 129.4

Thalassiodracon_hawkinsii 201.3 199.3

Hauffiosaurus_longirostris 182.7 174.1

Hauffiosaurus_tomistomimus 182.7 174.1 Hauffiosaurus_zanoni 182.7 174.1

Marmornectes_candrewi 166.1 163.5

Peloneustes_philarchus 166.1 163.5

Simolestes_vorax 166.1 163.5

Pliosaurus_funkei 152.1 145

Pliosaurus_westburyensis 157.3 152.1

Pliosaurus_carpenteri 157.3 152.1

Pliosaurus_brachydeirus 157.3 152.1

Pliosaurus_macromerus 157.3 152.1

Pliosaurus_brachyspondylus 157.3 152.1

Pliosaurus_cf_kevani 157.3 152.1

Pliosaurus_kevani 157.3 152.1

Gallardosaurus_iturraldei 163.5 157.3

Pliosaurus_rossicus 152.1 145

Pliosaurus_irgisensis 152.1 145

Pliosaurus_andrewsi 166.1 163.5

Liopleurodon_ferox 166.1 163.5

Kronosaurus_queenslandicus 121 100.5

Polyptychodon_sp 100.5 93.9

Megacephalosaurus_eulerti 93.9 89.8

Brachauchenius_lucasi 93.9 89.8

Brachauchenius_MNA 100.5 93.9

QM_F51291 105.5 100.5

Stenorhynchosaurus_munozi 129.4 125

Anguanax_zignoi 163.5 157.3

Makhaira_rossica 132.9 129.4

Luskhan_itilensis 132.9 129.4

Edgarosaurus_muddi 105.5 100.5 Plesiopleurodon_wellesi 100.5 93.9

Richmond_pliosaur 105.5 100.5

Palmulasaurus_quadratus 93.9 89.8

Pahasapasaurus_haasi 99.6 93.9

Polycotylus_latipinnis 89.8 83.6

Thililua_longicollis 93.9 89.8

Trinacromerum_bentonianum 100.5 89.8

Dolichorhynchops_osborni 83.6 80

Dolichorhynchops_bonneri 83.6 80

Eopolycotylus_rankini 93.9 89.8

Dolichorhynchops_tropicensis 93.9 89.8

Georgiasaurus_penzensis 86.3 83.6

Dolichorhynchops_ROM_29010 86.3 72.1

Dolichorhynchops_herschelensis 76.1 66

Sulcusuchus_erraini 76.1 66

Mauriciosaurus_fernandezi 93.9 89.8

Acostasaurus_pavachoquensis 129.4 125

Pliosaurus_patagonicus 152.1 145

Pliosaurus_almanzaensis 152.1 145

Sachicasaurus_vitae 129.4 125

Kronosaurus_boyacensis 121 113

13 Table S2. Bodyplan from Soul & Benson (2017) focussing on long necked plesiosaurians

14 (i.e. with Triassic sauropterygians, thalassophoneans, rhomaleaosaurids, and polycotylids

15 removed). The contribution column (“contrib”) indicates the average length of cervical

16 centra, obtained by dividing the neck length by the number of cervical centra. See Soul & 17 Benson (2017) and references therein for the data source. See also supplementary file

18 “SUPP_S&B2017_long_necked.csv”.

Length_including_h Neck_length_not_including_ Trunk_leng Cervic Dors contrib

ead head th al al

Albertonectes_vanderveldi_2007011 1120 700 188 76 18 9.210526315789

0001 47

Archaeonectrus_rostratus_38525 367 90 99 24 20 3.75

Attenborosaurus_conybeari_R1339 NA 181 NA 38 21 4.763157894736

Avalonnectes_arturi_14550 NA 69 54.5 25 19 2.76

Brancasaurus_brancai_A3B4 326 138 88.5 37 22 3.729729729729

Callawayasaurus_colombiensis_383 NA NA NA 56 25 NA

Colymbosaurus_trochanterius_3178 NA 200 153 41 21 4.878048780487

7 8

Cryptocleidus_eurymerus_3183 372 112 134 32 25 3.5

Cryptoclidus_eurymerus_R2860 NA 104 NA 32 25 3.25

Elasmosaurus_platyurus_10081 1130 667 214 71 23 9.394366197183

Eoplesiosaurus_antiquior_8348 NA 135 78 38 NA 3.552631578947

Hauffiosaurus_longirostris_1033 483 178 203 33 25 5.393939393939

Hauffiosaurus_tomistomimus_LL_8 445 152 127 34 21 4.470588235294

004 12

Hauffiosaurus_zanoni_uncatalogue 350 93 98 30 NA 3.1

Hydralmosaurus_serpentius_5835 1130 NA NA 63 19 NA Hydrotherosaurus_alexandrae_339 806 471 140 60 19 7.85

Kaiwhekea_katiki_12649 NA NA 195 53 23 NA

Libonectes_atlasense_3978 720 400 135 53 21 7.547169811320

Macroplata_tenuiceps_R5488 465 115 144 27 25 4.259259259259

Microcleidus_brachypterygius_5114 NA 142 71 36 18 3.944444444444

3 44

Microcleidus_brachypterygius_5114 203 85 NA 37 22 2.297297297297

1 3

Microcleidus_homalospondylus_LL NA 251 145 40 24 6.275

_7135

Microcleidus_homalospondylus_361 NA 210 NA 40 22 5.25

Microcleidus_indet_51945 NA 136.5 72.5 NA 20 NA

Microcleidus_tournemirensis_J_T_ 390 186 82.5 43 19 4.325581395348

86-100 84

Muraenosaurus_leedsii_R2421 NA NA NA 44 22 NA

Muraenosaurus_leedsii_R2863 NA 195 NA 41 26 4.756097560975

Nichollssaura_borealis_9412201 256 69 92.5 24 24 2.875

Picrocleidus_sp_G181996 NA 170.5 88 44 17 3.875

Plesiopterys_wildi_16812 242.5 88.5 63.5 40 23 2.2125

Plesiosaurus_brachypterygius_3185 299 115 NA 33 NA 3.484848484848

Plesiosaurus_dolichodeirus_22656 NA 115 NA 41 21 2.804878048780

Seelyosaurus_guilelmiimperatoris_5 358 126 94.5 33 21 3.818181818181

1015 82

Styxosaurus_snowii_451 NA 600 234.5 62 22 9.677419354838

71 Westphaliasaurus_simonsensii_P58 399 138 NA 23 21 6

091

23 24 Supplementary figures

Yunguisaurus liae Pistosaurus postcranium Augustasaurus hagdorni Bobosaurus forojuliensis Pistosaurus skull Anningasaura lymense Macroplata tenuiceps Avalonnectes arturi Rhomaleosaurus megacephalus Eurycleidus arcuatus Meyerasaurus victor Borealonectes russelli Maresaurus coccai Archaeonectrus rostratus Rhomaleosaurus thorntoni Rhomaleosaurus zetlandicus Rhomaleosaurus cramptoni Thalassiodracon hawkinsii Hauffiosaurus zanoni Hauffiosaurus tomistomimus Hauffiosaurus longirostris Anguanax zignoi Marmornectes candrewi Peloneustes philarchus Pliosaurus andrewsi Simolestes vorax Liopleurodon ferox Pliosaurus carpenteri Pliosaurus funkei Pliosaurus cf kevani Pliosaurus rossicus Pliosaurus almanzaensis Pliosaurus irgisensis Acostasaurus pavachoquensis Gallardosaurus iturraldei Pliosaurus brachyspondylus Pliosaurus brachydeirus Pliosaurus macromerus Pliosaurus kevani Pliosaurus westburyensis Brachauchenius MNA Brachauchenius lucasi QM F51291 Polyptychodon sp Megacephalosaurus eulerti Luskhan itilensis Makhaira rossica Pliosaurus patagonicus Kronosaurus queenslandicus Kronosaurus boyacensis Sachicasaurus vitae Stenorhynchosaurus munozi Stratesaurus taylori Attenborosaurus conybeari Eopleiosaurus antiquior Plesiosaurus dolichodeirus Eretmosaurus rugosus Westphaliasaurus simonsensii Seelyosaurus guilelmiimperatori Microcleidus tournemirensis Microcleidus homalospondylus Microcleidus brachypterygius Plesiopterys wildi Tatenectes laramiensis Kimmerosaurus langhami Tricleidus seeleyi Picrocleidus beloclis Muraenosaurus leedsii Cryptoclidus eurymerus Plesiosaurus mansellii Pantosaurus striatus Djupedallia engeri Spitrasaurus spp Abyssosaurus nataliae Colymbosaurus trochanterius Vectocleidus pastorum Brancasaurus brancai Gronausaurus wegneri Umoonasaurus demoscyllus Nichollssaura borealis Leptocleidus superstes Leptocleidus capensis Edgarosaurus muddi Hastanectes valdensis Palmulasaurus quadratus Pahasapasaurus haasi Richmond pliosaur Plesiopleurodon wellesi Sulcusuchus erraini Thililua longicollis Mauriciosaurus fernandezi Eopolycotylus rankini Polycotylus latipinnis Dolichorhynchops tropicensis Dolichorhynchops bonneri Trinacromerum bentonianum Dolichorhynchops osborni Dolichorhynchops ROM 29010 Georgiasaurus penzensis Dolichorhynchops herschelensis Jucha squalea Eromangasaurus australis Wapuskanectes betsynichollsae Elasmosaurus platyurus Nakonanectes bradti Speeton Clay Plesiosaurian Styxosaurus sp.Hydralm Styxosaurus snowii Morenosaurus stocki Aphrosaurus furlongi Vegasaurus molyi MLP 99 XII 1 5 Kawanectes lafquenianum Alexandronectes zealandiensis Tuarangisaurus keyesi Futabasaurus suzukii Kaiwhekea katiki Aristonectes parvidens Aristonectes quiriquinensis Morturneria seymourensis Libonectes morgani Zarafasaura oceanis Lagenanectes richterae Callawayasaurus colombiensis Thalassomedon haningtoni Cardiocorax mukulu Hydrotherosaurus alexandrae LACM 2832 Albertonectes vanderveldei Terminonatator ponteixensis Albian Aptian Norian Induan Danian Anisian Carnian Toarcian Ladinian Turonian Bajocian Aalenian Ypresian Rhaetian Callovian Tithonian Oxfordian Coniacian Selandian Thanetian Olenekian Bathonian Santonian Berriasian Barremian Hettangian Sinemurian Hauterivian Campanian Valanginian Cenomanian Maastrichtian Kimmeridgian Pliensbachian Wuchiapingian Changhsingian Lower Lower Lower Upper Upper Upper Middle Middle Eocene Lopingian Paleocene

Permian Triassic Jurassic Cretaceous Paleogene 90 80 70 60 50 25 250 240 230 220 210 200 190 180 170 160 150 140 130 120 110 100

26 Figure S 1. Strict consensus of the most parsimonious trees arising from our implied weight cladistic analysis. Yunguisaurus liae Pistosaurus postcranium Pistosaurus skull Augustasaurus hagdorni Bobosaurus forojuliensis Eopleiosaurus antiquior Attenborosaurus conybeari Thalassiodracon hawkinsii Stratesaurus taylori Anningasaura lymense Macroplata tenuiceps Avalonnectes arturi Eurycleidus arcuatus Archaeonectrus rostratus Rhomaleosaurus megacephalus Borealonectes russelli Maresaurus coccai Rhomaleosaurus thorntoni Meyerasaurus victor Rhomaleosaurus zetlandicus Rhomaleosaurus cramptoni Hauffiosaurus zanoni Hauffiosaurus tomistomimus Hauffiosaurus longirostris Anguanax zignoi Marmornectes candrewi Peloneustes philarchus Pliosaurus andrewsi Simolestes vorax Liopleurodon ferox Brachauchenius MNA Brachauchenius lucasi Megacephalosaurus eulerti Polyptychodon sp Kronosaurus boyacensis Sachicasaurus vitae Kronosaurus queenslandicus QM F51291 Makhaira rossica Acostasaurus pavachoquensis Pliosaurus patagonicus Luskhan itilensis Stenorhynchosaurus munozi Pliosaurus rossicus Pliosaurus macromerus Pliosaurus brachyspondylus Pliosaurus brachydeirus Pliosaurus westburyensis Pliosaurus kevani Pliosaurus almanzaensis Pliosaurus carpenteri Pliosaurus funkei Pliosaurus cf kevani Gallardosaurus iturraldei Pliosaurus irgisensis Plesiosaurus dolichodeirus Eretmosaurus rugosus Westphaliasaurus simonsensii Seelyosaurus guilelmiimperatori Microcleidus tournemirensis Microcleidus homalospondylus Microcleidus brachypterygius Plesiopterys wildi Plesiosaurus mansellii Pantosaurus striatus Picrocleidus beloclis Muraenosaurus leedsii Tricleidus seeleyi Tatenectes laramiensis Kimmerosaurus langhami Cryptoclidus eurymerus Spitrasaurus spp Djupedallia engeri Abyssosaurus nataliae Colymbosaurus trochanterius Aristonectes parvidens Kaiwhekea katiki MLP 99 XII 1 5 Morturneria seymourensis Aristonectes quiriquinensis Futabasaurus suzukii Tuarangisaurus keyesi Thalassomedon haningtoni Cardiocorax mukulu Libonectes morgani Zarafasaura oceanis Lagenanectes richterae Wapuskanectes betsynichollsae Speeton Clay Plesiosaurian Alexandronectes zealandiensis Brancasaurus brancai Gronausaurus wegneri Jucha squalea Callawayasaurus colombiensis Eromangasaurus australis Morenosaurus stocki Aphrosaurus furlongi Vegasaurus molyi Kawanectes lafquenianum Albertonectes vanderveldei Elasmosaurus platyurus Terminonatator ponteixensis LACM 2832 Hydrotherosaurus alexandrae Nakonanectes bradti Styxosaurus sp.Hydralm Styxosaurus snowii Vectocleidus pastorum Umoonasaurus demoscyllus Nichollssaura borealis Leptocleidus superstes Leptocleidus capensis Edgarosaurus muddi Hastanectes valdensis Palmulasaurus quadratus Pahasapasaurus haasi Sulcusuchus erraini Plesiopleurodon wellesi Richmond pliosaur Thililua longicollis Mauriciosaurus fernandezi Eopolycotylus rankini Polycotylus latipinnis Dolichorhynchops tropicensis Dolichorhynchops herschelensis Dolichorhynchops osborni Dolichorhynchops ROM 29010 Georgiasaurus penzensis Dolichorhynchops bonneri Trinacromerum bentonianum Albian Aptian Norian Induan Danian Anisian Carnian Toarcian Ladinian Turonian Bajocian Aalenian Ypresian Rhaetian Callovian Tithonian Oxfordian Coniacian Selandian Thanetian Olenekian Bathonian Santonian Berriasian Barremian Hettangian Sinemurian Hauterivian Campanian Valanginian Cenomanian Maastrichtian Kimmeridgian Pliensbachian Wuchiapingian Changhsingian Lower Lower Lower Upper Upper Upper Middle Middle Eocene Lopingian Paleocene

Permian Triassic Jurassic Cretaceous Paleogene 90 80 70 60 50 27 250 240 230 220 210 200 190 180 170 160 150 140 130 120 110 100 28 Figure S 2. Strict consensus of the most parsimonious trees arising from our equal weight cladistic analysis. 29 30 Figure S 3. Clade support by symmetric resampling, implied weighting analysis. 31 32 Figure S 4. Clade support by symmetric resampling, equal weighting analysis.

33 34 A Leptocleidians Styxosaurus browni 1.8 Early elasmosaurids Libonectes Terminonatator ponteixensis Euelasmosauridans morgani Aristonectine euelasmosauridans Additional elasmosaurids Elasmosaurus platyurus

Hydrotherosaurus alexandrae 'Woolungasaurus glendowerensis' Albertonectes vanderveldei

Styxosaurus sp. cf. Jucha ('Hydralmosaurus') Thalassomedon Cardiocorax mukulu Jucha squalea haningtoni Eromangasaurus Aphrosaurus furlongi 1.4 australis Kawanectes lafquenianum Tuarangisaurus keyesi Callawayasaurus Vegasaurus molyi colombiensis Nakonanectes bradti Styxosaurus

snowii Lagenanectes richterae Aristonectes parvidens Cervical elongation (length/height elongation ratio) Cervical

1.0 'Cimoliasaurus' Aristonectes quiriquinensis

Brancasaurus brancai

Edgarosaurus muddi

Early Cretaceous Late Cretaceous

145 100.5 66

B 3 density

0 1.0 1.2 1.4 1.6 1.8 Length/height ratio 35

36 Figure S 5. Patterns of vertebral elongation in cervical centra in elasmosaurids. A: phenogram using the

37 relatively longest centra of the neck, regardless of its position; additional elasmosaurids not included in the

38 phylogeny have been mapped as well (grey dots). B: density distribution of cervical elongation values for the

39 Early and Late Cretaceous.

40 41 References

42 Soul LC, Benson RBJ. 2017. Developmental mechanisms of macroevolutionary change in

43 the tetrapod axis: A case study of Sauropterygia. Evolution 71: 1164–1177.