SUPPLEMENT 1 Measurements of archosauriform (Osmolskina czatkowicensis Borsuk-Białynicka et Evans, 2003 and Collilongus rarus gen. et sp. n.) vertebrae from the Early Triassic karst deposits of Czatkowice 1, Poland (in mm) a - centrum length; d - centrum posterior depth; e - centrum posterior width. Measurement method follows Gower (2003, fig. 19); a/d - centrum length to posterior depth index.

A. Cervical vertebrae

Estimated a d a/d position Osmolskina czatkowicensis Cat.no. ZPAL RV/ 570 axis 6 5.8 1 610 axis 7.2 6 1.2 637 axis 7.9 6.1 1.3 672 axis 6.9 5 1.38

599 antcervical 7.3 4.8 1.5 636 antcervical 7.8 4.9 1.59 645 antcervical 6.5 5.0 1.3 668 antcervical 6.7 4.3 1.55

321 midcervical 8 5.6 1.4 571 midcervical 8 5.3 1.5 577 midcervical 7.1 5 1.42 593 midcervical 7.0 5.0 1.4 673 midcervical 6.2 4.2 1.47

573 postmidcervical 8.8 6.0 1.46 603 postmidcervical 7.0 4.9 1.43 608 postmidcervical 7.0 4.8 1.46 609 postmidcervical 9 5.7 1.6 609a postmidcervical 8.4 5.5 1.53 631 postmidcervical 8 5.4 1.6 638 postmidcervical 8.8 5.6 1.57 647 postmidcervical 7.9 5 1.58 664 postmidcervical 8.0 6 1.33 671 postmidcervical 6.3 4.9 1.29 680 postmidcervical 8.3 5.0 1.66 602 postcervical 7.2 5 1.44 607 postcervical 7.5 5.5 1.36

Collilongus rarus Cat.no. ZPAL RV/ 579 cervical 12.5 6.1 2.05 580 cervical 13.0 6.1 2.1 581 cervical 11.5 5.5 2.09 596 cervical 12.0 5.8 2.06 893 cervical/dorsal 11.0 6.1 1.8

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B. Dorsal vertebrae

Estimated a d a/d position Osmolskina czatkowicensis Cat.no.ZPAL RV/ 574 antdorsal 6.8 5.1 1.33 578 antdorsal 7.6 5.5 1.38 634 antdorsal 6.2 4.9 1.3 641 antdorsal 7.3 5 1.46 653 antdorsal 8.7 5.1 1.7

572 middorsal 8.8 5.0 1.76 632 middorsal 8.5 5.2 1.6 633 middorsal 8 5 1.6 650 middorsal 10 6.1 1.64 651 middorsal 10 6 1.66 652 middorsal 9 5.1 1.8 655 middorsal 8.3 5.5 1.5

572 postdorsal 8.6 5.2 1.6 575 postdorsal 9.8 6.1 1.6 648 postdorsal 9 6.1 1.47 656 postdorsal 8.4 52 1.6 658 postdorsal 8 5.4 1.48 Collilongus rarus Cat no. ZPAL RV/ 584 dorsal 14.27.2 1.57 585 dorsal 15.611 1.4 588 postdorsal 11.97.6 1.56 649 postdorsal 12. 8 1.5

C. Sacral and caudal vertebrae

Estimated a d e a/d d/e position Osmolskina czatkowicensis Cat.no.ZPAL RV/ 640 II sacral 8.0 5.0 5.2 1.6 0.96 642 I sacral 9.1 6.2 1.46 643 II sacral 8.2 6 1.36

657 antcaudal 8.3 6.8 7.0 1.22 0.97 576 antcaudal 8.3 6 6.9 1.38 0.87 658 antcaudal 7.7 5.9 6.4 1.3 0.92 659 antcaudal 8.3 6 1.38 660 antcaudal 8 6.6 6.9 1.21 0.95 1351 ?first caudal 8.9 6.0 6.0 1.29 1.0 1352 antcaudal 8.0 6.4 6.0 1.33 1.1 1353 antcaudal 7.0 5.5 5.3 1.27 1.03 1354 antcaudal 9.0 5.9 5.8 1.42 1.01 1355 antcaudal 8.0 5.5 5.8 1.4 0.94 1356 antcaudal 8.3 6.0 6.3 1.45 0.95 1357 antcaudal 9.0 7.0 7.0 1.3 1.0 1358 postcaudal 8.2 4.6 4.6 1.78 1.0

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1359 postcaudal 8.9 4.1 4.0 2.17 1.02 1360 postcaudal 7.8 3.8 3.8 2.05 1.0 1361 postcaudal 8.0 3.1 3.9 2.56 0.79 Collilongus rarus Cat.no. ZPAL RV/ 1362 ?first caudal 10.57.6 8.0 1.25 0.95 589 antcaudal 14 6.8*6.0 2.07 1.13 594 antcaudal 14 7.0 6.7 2.0 1.04 661 antcaudal 11.57.7 8.7 1.5 0.88 662 antcaudal 11 7.1 6.4 1.46 1.1

583 postcaudal 14.66.3 5.4 2.3 1.16 1363 postcaudal 11.85.5 4.8 2.1 1.15 1364 postcaudal 14.05.7 5.1 2.46 1.11 1365 postcaudal 13.05.0 4.5 2.6 1.11 1366 postcaudal 12.05.0 4.3 2.4 1.16 1367 postcaudal 12.04.5 4.0 2.66 1.12 1368 postcaudal 14.53.9 3.9 3.7 1.0 1369 sacral Additional 25 antcaudals and 18 postcaudals without cat nos have been included to Supplement 2

SUPPLEMENT 2

Frequency distribution of the lengths and proportions in the total sample of Archosauriform bones from the Early Triassic of Czatkowice 1, Poland.

A. Length of cervical vertebrae in mm (ax – axis) Length 5-5.9 6-6.9 7-7.9 8-8.9 9-9.9 10-10.9 11-11.9 12-12.9 13-13.9 N 2ax 2ax + 4 10 8 1 0 2 2 1

B. Centrum length (a) to posterior depth (d) index in cervical vertebrae (ax – axis) Ratio 1.01-1.1 1.11-1.2 1.21-1.3 1.31-1.4 1.41-1.5 1.51-1.6 1.61-1.7 1.71-1.8 1.81-1.9 1.91-2.0 2.01-2.1 2.11-2.2 N 1ax 1ax 1ax +3 1ax +4 9 7 1 1 0 0 4 0

C. Length of archosauriform dorsal vertebrae in mm Length 5-5.9 6-6.9 7-7.9 8-8.9 9-9.9 10-10.9 11-11.9 12-12.9 13-13.9 14-14.9 15-15.9

N 0 2 2 7 3 2 1 1 0 1 1

D. Centrum length (a) to posterior depth (d) index in dorsal vertebrae Ratio 1.21-1.3 1.31-1.4 1.41-1.5 1.51-1.6 1.61-1.7 1.71-1.8 1.81-1.9 N 1+1 3 5 7 3 1 0

E. Centrum length of caudal vertebrae (first number refers to anterior caudals, the second one to posterior caudals) Length in mm 5.0-6.9 7-8.9 9-10.9 11-12.9 13-14.9 15-16.9 N 3 + 1 22 + 13 10 + 1 5 + 8 1 + 7 0

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F. Centrum length (a) to posterior depth (d) index in caudal vertebrae (first number refers to anterior caudals, the second one to posterior caudals) Ratio 1.11-1.3 1.31-1.5 1.51-1.7 1.71-1.9 1.91-2.1 2.11- 2.3 2.31-2.5 2.51-2.7 2.71-2.9 2.91-3.1 3.11-3.3 3.31.-3.5 3.51-3.7 N 8 +0 15+0 9 +0 2 + 1 4 + 3 2 + 4 1+ 2 0 + 5 1 + 6 0 + 2 0 + 2 0 + 1 0 + 1

G. Centrum posterior depth (d) to width index in caudal vertebrae The second figure represents possible Longicollis caudals in each section Ratio 0.71-0.8 0.81-0.9 0.91-1.0 1.01-1.1 1.11-1.2 1.21-1.3 N 1 1+1 9+2 4+2 6 1

H. Estimated femur width

Femur: width of proximal end* 7- 8.9 9-10.9 11-12.9 13-14.9 15-16.9 17-18.9 in mm N 5 15 3 0 2 1

*directly above the IVth trochanter

SUPPLEMENT 3

Archosauriform genera consulted in the present studies. Russian materials from PIN RAS, Moscow (according to Sennikov 1995 and Gower and Sennikov 2000) Early archosauriform Age/ Provenance Assignment Current Est.skull taxa horizon of vertebrae locality basis affiliation length in cm Archosaurus Late Permian Vyazniki Skull fragments Proterosuchidae 30-35 Tatarinov, 1960 Upper Tatarian Vladimir Province 6 vertebrae Eastern Europe Chasmatosuchus Early Olenekian several localities Vertebrae + fragments Proterosuchidae 20 Huene, 1940 Rybinskian Eastern Europe Gamosaurus Ochev, Late Olenekian Zheshart Vertebrae only Proterosuchidae 20 1979 Yarenskian Komi Province Eastern Europe Proterosuchus Broom Lystrosaurus Zone South Africa, Complete skeleton and Proterosuchidae 14.8-27.5 1903 ?= Cape Province fragments (7 specimens) Chasmatosaurus Haughton, 1924 Sarmatosuchus Anisian Donguz Berdyanka Premaxilla, pterygoid, Proterosuchidae 35-40 Orenburg Province braincase-derived type, Sennikov, 1994 Eastern Europe scapulocoracoid, cervicals Vonhuenia Sennikov, Induan-Vokhmian Spasskoe Parabasisphenoid Proterosuchidae 15 1992 N. Novgorod Province Vertebrae, ilium Eastern Europe Chalishevia Ochev, Ladinian Bukobay Distinctive maxilla and Erythrosuchidae 90-110 1980 Bukobay Orenburg Province nasal; problematic Eastern Europe vertebrae

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Erythrosuchus Broom Anisian South Africa, Karoo Complete skeleton Erythrosuchidae Up to 100 1905 Basin known from 80 specimens Garjainia Ochev, Late Several loc. About 6 disarticulated Erythrosuchidae 45-60 1958 Olenekian Orenburg Province incomplete skeletons Yarenskian Eastern Europe Uralosaurus Anisian Donguz Several loc. Eastern Pterygoid, dentale, ?Erythrosuchidae 60-70 Sennikov, 1995 Europe some vertebrae Dorosuchus Anisian Donguz Berdyanka I Orenburg Braincase, pterygoid, Euparkeriidae 15-20 Sennikov, 1989 Province, Eastern ilium, some vertebrae Europe and long bones Euparkeria Broom, Anisian South Africa, Alival Complete skeleton Euparkeriidae 1913 North Osmolskina Borsuk- early Late Czatkowice 1 Southern Disarticulated Euparkeriidae 6-12 Białynicka and Olenekian karst Poland skeletons from Evans, 2003 deposits numerous individuals Batrachotomus Early Ladinian S.Germany Fairly full Rauisuchidae 40-50 Gower, 1999 documentation of the skeleton Dongusuchus Anisian Donguz Donguz I disarticulated long ?Rauisuchidae 25-30 Sennikov, 1988 Orenburg Province bones, 3 cervicals Eastern Europe Energosuchus Ochev, Ladinian Bukobay Bukobay V Orenburg Isolated long bones and ?Rauisuchidae 25-35 1986 Province vertebrae Eastern Europe Jaikosuchus Late Olenekian Rassypnaya Orenburg 3 cervicals and fibula ?Rauisuchidae 25 Sennikov, 1990 Yarenskian Province Eastern Europe Jushatyria Sennikov, Ladinian Bukobay Two localities. Fragmentary maxilla Rauisuchidae 35-40 1985 Eastern Europe isolated long bones and 3 vertebrae Postosuchus Late Carnian – North America Skull and disarticulated Rauisuchidae 65 Chatterjee, 1985 Early Norian skeletons Scythosuchus Late Olenekian Donskaya Luka Isolated skull and Rauisuchidae 30-35 Sennikov, 1999 (Yarenskian) Eastern Europe. postcranial bones Stagonosuchus Anisian Sothwestern Tansania 2 incomplete postcranial Rauisuchidae ? Huene, 1938 skeletons Ticinosuchus Krebs, Anisian/ Ladinian Val Porina, Monte San Damaged skeleton Rauisuchidae 26 1965 Giorgio, Switzerland Tsylmosuchus Olenekian, several localities Cervicals + rauisuchid ?Rauisuchidae 20 Sennikov (not (Rybinskian - Eastern Europe ilium (possibly T. Novikov), 1990 Yarenskian) jakovlevi from E.Olenekian) Vjushkovisaurus Anisian Donguz Berdyanka II Orenburg Articulated vertebrae, ?Rauisuchidae 25-35 Ochev, 1982 Province humerus Eastern Europe Vytshegdosuchus Late Olenekian Several loc. Rauisuchid fragmentary Rauisuchidae 25-30 Sennikov, 1988 (Yarenskian) Komi Province ilium vertebrae Eastern Europe Chinese materials

Fenchosuchus Young, Late Olenekian North China Disarticulated skeleton ?Rauisuchidae 1964 Anisian bones, vertebrae Xilousuchus Early Olenekian North China Partial skull, 12 ?Proterosuchidae ?25 Wu, 1981 He Shanggou vertebrae Shansisuchus Young, Late Olenekian North China Several skeletons Erythrosuchidae 42-56 1964 Wangisuchus Young, Late Olenekian North China Disarticulated skeleton ?Crurotarsi 1964 Anisian bones, vertebrae

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SUPPLEMENT 4

Variability ranges of the main parameters of cervical vertebrae in the archosauriform genera used in the paper. Measurements in mm.

Czatkowice 1 archosauriform vertebrae

Genus Estimated position a a/d N Age Osmolskina cervicals 5.5-9.0 1.3-1.8 34 Early Olenekian Longicollis cervicals 11-13.2 2.05-2.1 4 Early Olenekian

Proterosuchidae

Genus Estimated positiona mm a/d N Age Archosaurus midcervicals 25-33 1,23-1.25 3 Tatarian Chasmatosuchus midcervicals 19-27 1,59-1.8 6 Early Olenekian Rybinskian Gamosaurus midcervicals 19-22 1.64-1.76 3 Late Olenekian Yarenskian Proterosuchus antcervical 27 1.55 1 Induan Sarmatosuchus cervicals 30-32 0.97-1.14 5 Anisian Donguzian Vonhuenia midcervical 16 1.45 1 Induan

Proterosuchus according to Cruickshank 1972, fig. 4

Erythrosuchidae

Genus Estimated positiona mm a/d N Age Garjainia cervicals 34-46 0.72-1.10 7 Late Olenekian Yarenskian Uralosaurus midcervical 35 0,77 1 Anisian Donguz

Rauisuichidae

Genus Estimated a mm a/d N Age position Batrachotomus midcervical 41.5 0.68 1 Late Ladinian Ticinosuchus midcervical 44.6 1.62 1 Anisian/Ladinian Stagonosuchus cervicals III-V 60-76 0.83-1.06 4 Anisian Dongusuchus midcervical 36 1.95 1 Anisian Donguzian Energosuchus midcervicals 50-58 2.27-2.52 3 Ladinian Bukobay Jaikosuchus midcervical 40 1.74 1 Late Olenekian Yarenskian Jushatyria midcervical 64 1.33 1 Ladinian Bukobay Scythosuchus postcervical 29 1.59 1 Late Olenekian Yarenskian Tsylmosuchus midcervicals 30-40 2.0-2.50 7 early-Late Olenekian Vjushkovisaurus midcervical 46 1.59 1 Anisian Donguzian Vytshegdosuchus midcervicals 38-40 2.11 2 Late Olenekian Yarenskian

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