Fig 1.
Vertebrae 1–5 of Sylviornis neocaledoniae.
(A-E, a-e) anterior, (F-J, f-j) dorsal, (K-O, k-o) posterior, and (P-T, p-t) left lateral views. Photographs (A-T) and interpretive drawings (a-t): Vertebra 1, atlas, IANCP618 (A, F, K, P); vertebra 2, atlas, IANCP623 (B, G, L, Q); vertebra 3, IANCP621 (C, H, M, R); vertebra 4, IANCP622 (D, I, N, S); vertebra 5, IANCP631 (E, J, O, T). Abbreviations: aat, arcus atlantis; aax, arcus axialis; ac, ansa costotransversaria; ale, area lig. elastici; ave, arcus vertebrae; ca, corpus atlantis; faa, facies articularis atlantica; fac, facies artic. caudalis; facr, facies artic. cranialis; fazc, facies artic. zygapophysis caudalis; fazcr, facies artic. zygapophysis cranialis; fc, fossa condyloidea; fcr, fovea cranioventralis; for ac, foramen arcocostalis cranialis; fort, foramen transversarium; fv, foramen vertebrale; iac, incisura arcus caudalis; pac, proc. artic. caudalis; pc, proc. costales; ps, proc. spinosus; pv, proc. ventralis; pvl, proc. ventrolaterale; tub, tuberosity. Cross-hatching is missing bone.
Fig 2.
Vertebrae 6–10 of Sylviornis neocaledoniae.
(A-E) anterior, (F-J) dorsal, (K-O) posterior, and (P-T) left lateral views. Vertebra 6, IANCP632 (A,F,K,P); vertebra 7, IANCP633 (B,G,L,Q); vertebra 8, IANCP634 (C,H,M,R); vertebra 9, IANCP672 (D,I,N,S) with fragment of a rib adhering dorsally; vertebra 10, IANCP674 (E,J,O,T). Abbreviations: ac, ansa costotransversaria; fac, facies artic. caudalis; facr, facies artic. cranialis; fazc, facies artic. zygapophysis caudalis; fazcr, facies artic. zygapophysis cranialis; fort, foramen transversarium; fv, foramen vertebrale; pc, proc. costales; pcar, proc. caroticus; ps, proc. spinosus; pt, proc. transversus; pzca, proc. zygapophysis caudalis; td, torus dorsalis. Cross-hatching is missing bone.
Fig 3.
Vertebrae 11–15 of Sylviornis neocaledoniae.
(A-E) anterior, (F-J) dorsal, (K-O) posterior, and (P-T) left lateral views. Vertebra 11, IANCP676 (A,F,K,P mirrored); vertebra 12, IANCP679 (B,G,L,Q); vertebra 13, IANCP682 (C,H,M,R mirrored); vertebra 14, IANCP683 (D,I,N,S); vertebra 15, IANCP691 (E,J,O,T). Abbreviations: ac, ansa costotransversaria; ale, area lig. elastici; ave, arcus vertebrae; fac, facies artic. caudalis; facr, facies artic. cranialis; fazc, facies artic. zygapophysis caudalis; fazcr, facies artic. zygapophysis cranialis; fcc, fovea costalis capituli; fcr, fovea cranioventralis; fct, fovea costalis tuberculi; fort, foramen transversarium; fv, foramen vertebrale; ps, proc. spinosus; pt, proc. transversus; pv, proc. ventralis; pzca, proc. zygapophysis caudalis.
Fig 4.
Vertebrae 16–20 of Sylviornis neocaledoniae.
(A-C) Anterior, (D-F) posterior, (G-I) dorsal, and (J-L) right lateral views. Vertebra 16, IANCP692 (A,D,G,J); notarium, vertebrae 17–19, IANCP697 (B,E,H,K); vertebra 20, IANCP690 (C,F,I,L). Abbreviations: ale, area lig. elastici; ave, arcus vertebrae; fac, facies artic. caudalis; facr, facies artic. cranialis; fazc, facies artic. zygapophysis caudalis; fazcr, facies artic. zygapophysis cranialis; fcc, fovea costalis capituli; fct, fovea costalis tuberculi; fv, foramen vertebrale; ps, proc. spinosus; pt, proc. transversus; pv, proc. ventralis; pzca, proc. zygapophysis caudalis.
Fig 5.
Pelvis of Sylviornis neocaledoniae.
(A, B) synsacral fragment (IANCP559), (C) right acetabulum and ischium (IANCP557). Abbreviations: a, antitrochanter; cv, crista ventralis; fa, foramen acetabuli; fcc, foveae costales capituli; fi, foramen ilioischiadicum; pli, processus lateralis for articulation with ilium.
Fig 6.
Photographs of pectoral girdle elements of Sylviornis neocaledoniae.
Left humerus IANCP1033 in cranial (A) and caudal (B) views. Right ulna IANCP1034 in internal (C) and ventral (D) views. Right radius IANCP1041 in caudal (E) and dorsal (F) views. Right carpometacarpus IANCP1038 in ventral (G), dorsal (H) and caudal (I) views. Left scapulae IANCP1036 (J, L) and IANCP1037 (K, M) in medial (J, K) and lateral (L, M) views. Left coracoid IANCP1032 in dorsal (N), medial (O), lateral (P) and ventral (Q) views. Sternum IANCP1060 in anterior view (R). Scale bars are 5 cm.
Fig 7.
Interpretive drawings of pectoral girdle elements of Sylviornis neocaledoniae.
Left humerus IANCP1033 in cranial (A) and caudal (B) views. Right ulna IANCP1034 in internal (C) and ventral (D) views. Right radius IANCP1041 in caudal (E) and dorsal (F) views. Right carpometacarpus IANCP1038 in ventral (G), dorsal (H) and caudal (I) views. Left scapulae IANCP1036 (J, L) and IANCP1037 (K, M) in medial (J, K) and lateral (L, M) views. Left coracoid IANCP1032 in dorsal (N), medial (O), lateral (P) and ventral (Q) views. Sternum IANCP1060 in anterior view (R). Abbreviations: ac, acromion; acr, acrocoracoid; c, caput; cb, crista bicipitalis; cd, condylus dorsalis; cde, crista deltopectoralis; cdo, cotyla dorsalis; clap, crista lig. acrocoraco-procoracoideum; cs, cotyla scapularis; cve, cotyla ventralis; dl, depressio ligamentosa; dr, depressio radialis; fac, facies artic. coracoideum; facs, facies artic. coracoideus on sternum; fah, facies artic. humeralis; fdIII, origin m. flexor digiti III; fmai, fossa m. abductor indicis; fpv, fossa pneumotricipitalis ventralis; ib, impressio brachialis; ibu, impressio brachialis ulnaris; ic, incisura capitis; icb, impressio coracobrachialis; icc, insertii m. coracobrachialis caudalis; ims, impressio m. supracoracoideus; irp, insertions remiges primarii; is, impressio sternocoracoidei; ld, attachment m. latissimus dorsalis; o, olecranon; omma, os metacarpale majus; ommi, os metacarpale minus; pc, processus costales; pe, processus extensorius; pf, pneumatic foramen; pfl, processus flexorius; pp, processus pisiformis; si, spatium intermetacarpale; sms, sulcus m. supracoracoideus; tc, trochlea carpalis; tsd, tuberculum supracondylaris dorsalis; tuc, tuberculum carpale; tv, tuberculum ventrale.
Table 1.
Summary statistics of measurements (mm) for humeri of Sylviornis neocaledoniae.
Table 2.
Summary statistics of measurements (mm) for ulnae, radii and carpometacarpi (cmc) of Sylviornis neocaledoniae.
Ulna DW is width across condylus dorsalis ulnaris, ulna SW is dorsoventral width at mid length.
Table 3.
Measurements of scapulae of Sylviornis neocaledoniae: A, acromion to cranioventral side of facies articularis humeralis; B, dorsoventral depth of collum at cranial side of tuberculum m. scapulotricipitis; C, length from cranial side of acromion to preserved distal end.
Table 4.
Summary statistics of measurements (mm) for coracoids of Sylviornis neocaledoniae.
Abbreviations: L, length; AL, acrocoracoid length from the cotyla scapularis; minSW, minimum shaft width in dorsal view; StnW, sternal width.
Fig 8.
Femora of Sylviornis neocaledoniae.
(A, B) left, IANCP529; (C, D) right, IANCP564; and (E) proximal right, IANCP527+535, in caudal (A), medial (B), cranial (C) and lateral (D, E) views. Abbreviations: c, collum; cl, condylus lateralis; cm, condylus medialis; csm, crista supracondylaris medialis; ct, crista trochanteris; faa, facies artic. antitrochanterica; fp, fossa poplitea; ft, fossa trochanteris; ftmt, fovea tendineus m. tibialis; imp, insertion for m. puboischiofemoralis; lcc, insertion for lig. cruciatum craniale; lic, linea intermuscularis caudalis; licr, linea intermuscularis cranialis; mica, insertion for m. iliotrochanterica caudalis; micr, insertion for m. iliotrochanterica cranialis; mie, insertion for m. iliofemoralis externus; mif, insertion for ischiofemoralis; mim, insertion for m. iliotrochanterica medialis; mgl, insertion for m. gastrocnemialis lateralis; mom, insertion for m. obturatorius medialis; mol, insertion for m. obturatorius lateralis; sp, sulcus patellaris; tf, trochlea fibularis.
Table 5.
Measurements (mm) of femora of Sylviornis neocaledoniae: Proximal width (PW) is maximum, shaft width and depth (SW, SD) were taken at mid length, and distal width (DW) is maximum.
Contributing specimens: IANCP526+543, IANCP527+535, IANCP528, IANCP529, IANCP531+547, IANCP532, IANCP534, IANCP538, IANCP542, IANCP564, IANCP1031.
Fig 9.
Tibiotarsi of Sylviornis neocaledoniae.
(A-D) right, IANCP980 and (E) proximal right IANCP1013, in anterior (A), caudal (B), medial (C), lateral (D) and proximal (E) views. Abbreviations: ccc, crista cnemialis cranialis; ccl, crista cnemialis lateralis; cf, crista fibularis; cl, condylus lateralis; cm, condylus medialis; del, depressio epicondylaris lateralis; ditl, distal insertion of transverse ligament; fal, facies artic. lateralis; ff, fossa flexoria; fmp, fossa for origin of m. plantaris; fr, fossa retropatellaris; iclm, impressio lig. collateralis medialis; ii, incisura intercondylaris; it, incisura tibialis; pons, pons supratendineus; prom, prominence in area interarticularis; se, sulcus extensorius.
Table 6.
Measurements (mm) of tibiotarsi of Sylviornis neocaledoniae.
Abbreviations: TL, total length is the maximum from the crista cnemialis cranialis to distal end of the condylus medialis, which was estimated here based on IANCP 980 completed with reference to IANCP1013; PW, proximal width is the maximum across the articular facies; PD proximal depth is from crista cnemialis cranialis to the caudal margin of facies articularis medialis; SW, shaft width is the minimum in the distal third of shaft; DW, distal width is a maximum; DLC, depth condylus lateralis was taken on a plane at right angle to shaft; DMC, depth condylus medialis was maximum craniocaudal depth. Contributing specimens: IANCP718, IANCP723, IANCP980, IANCP981, IANCP982, IANCP983, IANCP984, IANCP985, IANCP986, IANCP988, IANCP989, IANCP990, IANCP991, IANCP992, IANCP993, IANCP994, IANCP995, IANCP1003, IANCP1004, IANCP1005, IANCP1007, IANCP1008, IANCP1009, IANCP1010, IANCP1012, IANCP1013, IANCP1027.
Fig 10.
Left tarsometatarsus of Sylviornis neocaledoniae.
(A-F) IANCP976, in anterior (A), caudal (B), lateral (C), medial (D), distal (E) and proximal (F) views. Abbreviations: ai, area intercotylaris; cl, cotyla lateralis; clh, crista lateralis hypotarsi; cm, cotyla medialis; cmh, crista medialis hypotarsi; ei, eminentia intercotylaris; fdl, sulcus for tendon of m. flexor digitorum longus; flc, fovea ligamentum collateralis; fmI, fossa metatarsi I; fpl, foramen vasculare proximale lateralis; fpm, fossa parahypotarsalis medialis; fsp, fossa supratrochlearis plantaris; fvd, foramen vasculare distale; iil, incisura intertrochlearis lateralis; se, sulcus extensorius; TII, trochlea metatarsi II; TIV, trochlea metatarsi IV; ttc, tuberositas m. tibialis cranialis.
Table 7.
Measurements (mm) for tarsometatarsi: TL (greatest length), PW proximal width from cotyla medialis to cotyla lateralis, PD proximal depth from crista medialis hypotarsi to the highest point of the cotyla medialis, DW distal width across trochlea metatarsi II to trochlea metatarsi IV, DMC depth of medial cotyla, WFPM width of fossa parahypotarsalis medialis, SW1 width of shaft at thinnest point = midlength, SW2 width of shaft at proximal side of fossa metatarsi I, SD1 shaft depth at SW1, SD2 shaft depth at SW 2, HD, hypotarsus depth from the base of the hypotarsus to the eminentia intercotylaris, DT3 depth of lateral rim of trochlea metatarsi III, WT3 width of trochlea metatarsi III.
Fig 11.
Composite foot of Sylviornis neocaledoniae compared to that of Leipoa ocellata scaled to the same absolute size.
(A) Sylviornis neocaledoniae: tarsometatarsus is IANCP976 reversed, the phalanges are IANCP731 (reversed), 733–745, and 754 (reversed). (B) Leipoa ocellata SAM B.11482. Note that the digits of S. neocaledoniae are relatively shorter, especially digits 2 and 4, and the unguals are much shorter. Scale bars are 10 cm.
Table 8.
Measurements (mm) of metatarsal I.
The proximal facet articulates with the metatarsal facet on the tarsometatarsus. Material: IANCP731, IANCP764-767, IANCP833-836, NISP = 9.
Table 9.
Measurements (mm) of phalanx I.1.
Material: IANCP572, IANCP732, IANCP749-756, IANCP815, IANCP839-852. NISP = 25.
Table 10.
Measurements (mm) of phalanx I.2.
Material: IANCP733, IANCP801-802, IANCP856, IANCP863, IANCP874-875, IANCP876-883; NISP = 15.
Table 11.
Measurements (mm) of phalanx II.1.
Material: IANCP569, IANCP734, IANCP758, IANCP768-776, IANCP816-817, IANCP884-892; NISP = 23.
Table 12.
Measurements (mm) of phalanx II.2.
Material: IANCP735, IANCP759, IANCP777-779, IANCP893-898, IANCP948; NISP = 12.
Table 13.
Measurements (mm) of phalanx II.3.
Material: IANCP736, IANCP803-804, IANCP806, IANCP864-867; NISP = 8.
Table 14.
Measurements (mm) of phalanx III.1.
Material: IANCP737, IANCP760-761, IANCP780-787, IANCP818, IANCP899-910, IANCP949, IANCP964; NISP = 26.
Table 15.
Measurements (mm) of phalanx III.2.
Material: IANCP738, IANCP762-763, IANCP788, IANCP789-791, IANCP819-822, IANCP911-926, IANCP965; NISP = 28.
Table 16.
Measurements (mm) of phalanx III.3.
Material: IANCP739, IANCP927-929; NISP = 4.
Table 17.
Measurements (mm) of phalanx III.4.
Material: IANCP740, IANCP805, IANCP807-809, IANCP824-825, IANCP868-869; NISP = 9.
Table 18.
Measurements (mm) of phalanx IV.3.
Material: IANCP741, IANCP746, IANCP792-799, IANCP826, IANCP936-944, IANCP951-953, NISP = 23.
Table 19.
Measurements (mm) of phalanx IV.2.
Material: IANCP742, IANCP747, IANCP800, IANCP827-828, IANCP945, IANCP954-958, IANCP967; NISP = 12.
Table 20.
Measurements (mm) of adult phalanges IV.3 and IV.4.
Material: Phalanx IV.3: IANCP743, IANCP748, IANCP829, IANCP959-960, IANCP968; NISP = 6, only 1 is adult. Phalanx IV.4: IANCP830.
Table 21.
Measurements (mm) of phalanx IV.5.
Material: IANCP810, IANCP811, IANCP870, IANCP871, IANCP872, IANCP783.
Table 22.
Phalanges compared—means values for S. neocaledoniae (from Tables 8–21) compared to summary statistics (mean, [mean divided by tmtL*100], standard deviation, and range) data for L. ocellata and A. lathami, and selected individuals of various other megapode species.
Leipoa ocellata specimens (n = 11): SAM B414, SAM B1094, SAM B5039, SAM B11482, SAM B47825, SAM B48526, SAM B48765, SAM B49461, SAM B55458, SAM B55528, SAM B58520; Alectura lathami specimens (n = 7): SAM B46568, MV B11471, MV B19290, QM O27852, QM O27218, QM O27843, QM O27844.
Fig 12.
PCA plot showing separation of S. neocaledoniae from various megapodes and Gallus gallus.
The plot is based on leg bone measurements standardised for size using femur length and selected ratios of some lengths divided by tarsometatarsus length of various galliforms compared to (see S1 File).
Fig 13.
The strict consensus tree from parsimony and ordered analysis with a molecular backbone constraint.
In this analysis, relationships between taxa with molecular data (living taxa and moa) were constrained, with other (fossil) taxa free to move to their optimal positions within this backbone. Tree statistics: Length 1425, Consistency index = 0.2786, Homoplasy index = 0.7214, Retention index = 0.6295. The Bootstrap and probability values of the other analyses (Parsimony, unordered, Bayesian ordered and unordered) are shown, with a dash to indicate clade not found.
Fig 14.
The strict consensus from parsimony and ordered analysis with only ingroup-outgroup constraints.
The ingroup-outgroup constraint was (Palaeognaths ((neognaths) (galloanseres)) wherein all taxa were free to move within but not between these three clades. Three MPTs were found Length 1395, Consistency index = 0.2846, Homoplasy index = 0.7154, Retention index = 0.6404. The bootstrap and probability values of the other analyses (Parsimony, unordered, Bayesian ordered and unordered) are shown, with a dash to indicate that the clade not found. We consider this tree less plausible than the one in Fig 13 (see main text).
Fig 15.
A skeletal reconstruction for Sylviornis neocaledoniae in a resting pose.
The missing skeletal parts are estimated (shaded bones), with the pelvis based on proportions of Leipoa ocellata. The bill rhamphotheca is not reconstructed so as to not obscure the underlying skeletal morphology.