Figure 1.
Maps of the study area in Svalbard, Norway.
A: Palaeogeographic map of the North Atlantic region in the Late Jurassic, modified from Torsvik et al. [2]. The red dot locates the study area; B: Geological map of the study area including the Agardhfjellet Formation and dig sites. The black arrow points to the site where specimen PMO 222.654 was excavated. Modified from Hurum et al. [1] and Dallmann et al. [14].
Figure 2.
The stratigraphic position the described Spitsbergen ophthalmosaurids.
Janusaurus lundi (PMO 222.654) in reference to Palvennia hoybergeti (SVB 1451) and Cryopterygius kristiansenae (PMO 214. 578). Adapted from Hurum et al. 2012.
Figure 3.
The specimen is presented showing the better preserved (stratigraphical-down) side after it was prepared. Dashed lines indicate boundaries of each of the four field jackets made at the time of collection. (Adapted from Novis [36]). Scale = 1 m.
Figure 4.
The skull of Janusaurus lundi (PMO 222.654).
A: Photo in right lateral view of the skull. B: Right lateral view with interpretation of the individual elements. Abbreviations: a, angular; art, articular; d, dentary; en, external naris; j, jugal; l, lacrimal; mx, maxilla; n, nasal; or, orbit; p, parietal; pmx, premaxilla; po, postorbital; pof, postfrontal; prf, prefrontal; q, quadrate; qj, quadratojugal; sa, surangular; st, supratemporal. Scale = 5 cm.
Figure 5.
Oblique dorsal view of the skull of Janusaurus lundi (PMO 222.654).
The dotted lines mark eroded or equivocal sutures. Abbreviations: p, parietal; pfor, pineal foramen; prf, prefrontal; pof, postfrontal; po, postorbital; q, quadrate; qj, quadratojugal; st, supratemporal; stf, supratemporal fenestra. Scale = 1 cm.
Figure 6.
The basioccipital and right stapes from Janusaurus lundi (PMO 222.654).
A: posterior view of the basioccipital; B: anterior view of the basioccipital; C: dorsal view of the basioccipital; D: ventral view of the basioccipital; E: lateral view of the right stapes, F: medial view of the medial head of the right stapes; G: anterior view of the right stapes; H: posterior view of the right stapes. Abbreviations: baf/bsf, basioccipital and basisphenoid facet;bsf, basiospenoid facet; hp, hyoid facet; oc, occipital condyle; opf, opisthotic facet; qf, quadrate facet; stf, stapes facet. Scale = 1 cm.
Figure 7.
Medial view of the preserved right mandible of Janusaurus lundi (PMO 222.654).
Medial view of the posterior portion of the right mandible and the posterior portion of the palate. Abbreviations: a, angular; art, articular; cor, coronid process; part, prearticular; partp, prearticular dorsal process; pgp, preglenoid process; pt, right pterygoid; sa, surangular. Scale = 1 cm.
Figure 8.
The right hyoid from Janusaurus lundi (PMO 222.654).
Posterior is to the left, anterior to the right. Ventral view is situated at the top, dorsal view below. Scale = 1 cm.
Figure 9.
Pectoral girdle of Janusaurus lundi (PMO 222.654).
A: posterior view of the left clavicle; B: posterior view of the right clavicle; C: anterior view of the left clavicle; D: anterior view of the right clavicle; E: ventral view of the interclavicle; F: dorsal view of the interclavicle; G: dorsal? view of the right scapula; H: dorsal view of the left coracoid; I: dorsal view of the right coracoid. Abbreviations: amp, anteromedial process; ict, interclavicular trough; ms, medial symphysis; sb, scapular blade; vf, ventral foramen. Scale = 5 cm.
Figure 10.
A: dorsal view with articulating elements; B: ventral view; C: proximal view; D: anterior view; E: posterior view; F: distal view. Abbreviations: er, elevated rim; dpc, deltopectoral crest; dp, dorsal process; pe, preaxial accessory element; pef, preaxial accessory element facet; i, intermedium; r, radiale; R, radius; Rf, radial facet; U, ulna; Uf, ulnar facet. Scale = 5 cm.
Figure 11.
Ilia and left ischiopubis of Janusaurus lundi (PMO 222.654).
A: lateral view of the right ilium; B: lateral view of the left ilium; C: medial view of the right ilium; D: medial view of the left ilium; E: dorsal view ilia; F: medial side of the left ischiopubis; G: lateral side of the left ischiopubis. Abbreviations: adp, anterodorsal process; af, acetabular facet; ipf, ischiopubic facet. Scale = 1 cm.
Figure 12.
The left femur of Janusaurus lundi (PMO 222.654).
A: dorsal view; B: ventral view; C: proximal view; D: anterior view; E: posterior view; F: distal view. Abbreviations: dp, dorsal process; ff, fibular facet; tf, tibial facet; vp, ventral process. Scale = 1 cm.
Figure 13.
The axial skeleton of Janusaurus lundi (PMO 222.654).
Including the partial atlas-axis complex, complete trunk vertebra, neural arches, dorsal rib and gastralia from PMO 222.654. A: lateral? view of atlas-axis complex; B: anterior view of atlas-axis complex; C: lateral view of trunk vertebrae; D: anterior view of trunk vertebrae; E: posterior view of trunk vertebrae; F: dorsal view of trunk vertebrae; G: neural arch from the sacral region in anterior view; H: neural arch from the trunk region in lateral view; I: nearly complete dorsal rib; J: complete gastralium. Abbreviations: prz, prezygapophysis; dp, diapophysis; ns, neural spine; pp, parapophysis. A-H Scale = 1 cm, I Scale = 10 cm, J Scale = 1 cm.
Figure 14.
Skull reconstruction of Janusaurus lundi in right lateral view.
Abbreviations: a, angular; art, articular; bo, basioccipital; d, dentary; en, external naris; j, jugal; l, lacrimal; mx, maxilla; n, nasal; or, orbit; p, parietal; pmx, premaxilla; po, postorbital; pof, postfrontal; prf, prefrontal; q, quadrate; qj, quadratojugal; sa, surangular; st, supratemporal; stf, supratemporal fenestra.
Table 1.
Selected cranial measurements of PMO 222.654 (in mm).
Table 2.
Selected braincase measurements of PMO 222.654 (in mm).
Table 3.
Selected mandibular measurments from PMO 222.654 (in mm).
Table 4.
Selected pectoral girdle measurements of PMO 222.654 (in mm).
Table 5.
Selected measurements from the left humerus of PMO 222.654 (in mm).
Table 6.
Selected pelvic girdle measurements of PMO 222.543 (in mm).
Table 7.
Selected femora measurements of PMO 222.654 (in mm).
Figure 15.
Strict consensus tree of the family Ophthalmosauridae.
The tree is formed of three MPTs with 128 steps, showing relationships among Ophthalmosauridae and the outgroups. Boot strap value marked with number for values >50%, Bremer Support values shown for 2 and above.