Figure 1
Map showing the location of the 'cemitério dos pterossauros' site in Cruzeiro do Oeste (red arrow), Paraná State, southern Brazil. (a) The outcrops of the Bauru Basin (light grey) in Brazil, (b) detail of the Bauru basin with the Rio Paraná (light green), Goio-Erê (light blue), Santo Anastácio (grey) formations, and the Bauru Group (dark grey), and (c) stratigraphic chart showing the relations of the former, including the underlying Serra Geral Formation (green).
Figure 2
Stratigraphic sequence of the 'cemitério dos pterossauros' site, showing the recorded taxa (Caiuajara dobruskii, Vespersaurus paranaensis and Keresdrakon vilsoni) in the four (A-D) bonebeds, the correspondent depositional environments, and the sedimentary structures. Note that in bonebed D only small individuals of Caiuajara were collected.
Figure 3
Holotype of Keresdrakon vilsoni gen. et sp. nov. (CP.V 2069). Skull and lower jaw are presented in right lateral view. Abbreviations: cra - skull, cv - cervical vertebra, fe - femur, gas - gastralia, hu - humerus, man - mandible, q - quadrate, ra - radius, ri - ribs, sca - scapula, st - sternum, ti - tíbia; l - left, r - right. Scale bar = 100mm.
Figure 4
Skull and lower jaws of Keresdrakon vilsoni gen. et sp. nov. (a) Incomplete skull showing the rostral part, in left lateral view (CP.V 2068), (b) incomplete lower jaw (CP.V 2069 part of the holotype) in left lateral and (c) dorsal views, (d) anterior portion of a dentary (CP.V 2070) in left lateral and (e) dorsal views. Abbreviations: d - dentary, dcr - dentary crest, fo - foramina, gr - groove, m - maxilla, naof - nasoantorbital fenestra, pm - premaxilla, rid - ridge, spl - splenial; l - left, r - right. Scale bar = 50mm.
Figure 5
- Cervical vertebrae of Keresdrakon vilsoni gen. et sp. nov., CP.V 6495 in (a) ventral, (b) right lateral, (c) dorsal and (d) anterior views; CP.V 2445 in (e) ventral, (f) dorsolateral, (g) posterior views. Note the ossified tube that encloses the neural cannal in (F) marked by an arrow. Abbreviations: con - condyle, fo - foramen, fopn - foramen pneumaticum, hyp - hypapophysis, nc - neural canal, ns - neural spine, poex - postexapophysis, poz - postzygapophysis, prex - preexapophysis, prz - prezygapophysis, tra - trabeculae. Scale bar = 20mm.
Figure 6
Sternum of Keresdrakon vilsoni gen. et sp. nov. (CP.V 2069, part of the holotype). (a) ventral, cristospine in dorsal (b) and (c) right lateral views. Abbreviations: afc - articular facet for coracoid, cs - cristospine, fo - foramen, stp - sternal plate Scale bars = (a) and (b) 50mm, (c) 20mm.
Figure 7
Keresdrakon vilsoni gen. et sp. nov. (a) complete left first phalanx of manual digit IV (CP.V 2248), (b) proximal articulation of left first phalanx of manual digit IV (CP.V 2248), (c) proximal articulation of right first phalanx of manual digit IV (CP.V 2373); right humerus (CP.V 1011) in (d) medial, (e) dorsal, (f) ventral and (g) lateral views; left incomplete coracoid in (h) ventral and (i) dorsal views, (j) scapula in dorsal view. Abbreviations: dpc - deltopectoral crest, fopn - foramen pneumaticum, tucor - coracoidal tuberculum. Scale bars = (b) and (c) 10mm, all others 50mm.
Figure 8
Keresdrakon vilsoni gen. et sp. nov., pelvis (CP.V 2869, part of the holotype), (a) left ischium in lateral view; right pubis in (b) medial and (c) lateral views; right ischium in (d) lateral and (e) medial views. Abbreviations: ac - acetabulum, fo - foramen, gas - gastralia, obfo - obturator foramen. Scale bar = 50mm.
Figure 9
Osteohistological sections ofKeresdrakon vilsonigen. et sp. nov. appendicular elements. Incomplete first wing phalanx of digit four (CP.V 2374) (a) and osteohistological cross section of the diaphysis; left ulna (CP. V 2077) (c) and respective osteohistological cross section of the diaphysis. Abbreviations: lag - line of arrested growth, vc - vascular canal. The yellow arrows point where the samples were taken. Scale bar = (a) and (c) 50mm, (b) and (d) 200µm.
Figure 10
Time-calibrated phylogenetic tree showing the relationships of Keresdrakon vilsoni gen. et sp. nov. within the Pterodactyloidea. Intermittent bars show uncertain temporal range. Letters in intermittent bars indicate controversial age hypotheses of the Goio-Erê Formation: (a) Albian-Aptian; (b) Turonian-Campanian. Outgroup relationships are not shown (see Holgado et al. 2019 - Supplementary Information for further details). Stratigraphic chart modified from Cohen et al. (2013COHEN KM, FINNEY SM, GIBBARD PL and FAN JX. 2013. The ICS International Chronostratigraphic Chart. Episodes 36: 199-204.).
Figure 11
Sample (CP.V 6559) from bonebed A of Figure 2, showing on the left (a) side a partial skeleton of the pterosaur Caiuajara dobruskii and on the right (b) the remains of the dinosaur Vespersaurus paranaensis. White line shows the limits between the two specimens. Scale bar = 100mm.
Figure 12
Sample (CP.V 7228) from bonebed A of Figure 2 showing the close association of a femur of Caiuajara dobruskii (a) and the incomplete tail and forelimb (including partial manus) of Vespersaurus paranaensis (b), separated by the white line. Scale bar = 100mm.
Figure 13
Paratype of Caiuajara dobruskii (CP.V 1003) (a) and a partial articulated hind limb of Vespersaurus paranaensis with tibia, fibula, tarsals (including astragalus) and metatarsals on the upper right corner (b). This specimen was collected from bonebed C of Figure 2. White line shows the limits of the two specimens. Scale bar = 100mm.
Figure 14
Sample (CP.V 1007) from bonebed level C of Figure 2, showing the close association of Caiuajara dobruskii (a) and Vespersaurus paranaensis (b) separated by the white line. Scale bar = 100mm.
Figure 15
Sample (CP.V 5697) from bonebed C of Figure 2, showing on the right (a) a partial skeleton of the Caiuajara dobruskii the left (b) elements of Keresdrakon vilsoni gen. et sp. nov. separated by the white line. Scale bar = 100mm.
Figure 16
Sample (CP.V 2374) from bonebed C of Figure 2, showing two caudal vertebrae from Vespersaurus paranaensis (a), the diaphysis of a large first phalanx of manual digit IV of Keresdrakon vilsoni gen. et sp. nov. (b), and bones of Caiuajara dobruskii (c), separated by the white line. Abbreviations: cdr - caudal vertebrae, ph1d4 - first phalanx of manual digit IV. Scale bar = 100mm.
Figure 17
Reconstruction of the paleoenvironment showing the possible interaction of the vertebrate fauna recovered from the 'cemitério dos pterossauros' site. See text for details. Artwork by Maurilio Oliveira.