Figure 1.
Locality and horizon of Pliosaurus kevani n. sp. DORCM G.13,675.
Maps of the United Kingdom (A), Dorset area (B), and Osmington Bay (D) showing the locality of the specimen, indicated by a pliosaurid silhouette. The stratigraphic context of the find (C), the approximate level of the Wyke Siltstone bed is marked by a pliosaurid silhouette and the stratigraphic section at Black Head was given in full by ([63]:fig. 6). The mounted skull of DORCM G.13,675 in left lateral view (E). Scale bars equal 500 m (D) and 500 mm (E).
Figure 2.
Cranium of Pliosaurus kevani n. sp. DORCM G.13,675 in dorsal view (A–B).
In line drawing (B) dark grey tone represents broken bone surface, mid grey represents matrix, and light grey represents tooth or artificial restoration. Abbreviations: bat, basal tuber; en, external naris; exoc-opis, exoccipital-opisthotic; fr, frontal; jug, jugal; lac, ‘lacrimal’; mx, maxilla; pal, palatine; par parietal; pmx, premaxilla; po, postorbital; pofr, postfrontal; prfr, prefrontal; pt, pterygoid; rug, rugose eminence; soc (l), left portion of supraoccipital; soc (r), right portion of supraoccipital; sq, squamosal. Ss
Figure 3.
Reconstruction of the skull of Pliosaurus kevani n. sp.
In right lateral (A), dorsal (B), and ventral (C) views. Abbreviations: ang, angular; art, articular; den, dentary; en, external naris; exoc-opis, exoccipital-opisthotic; in, internal naris; jug, jugal; fr, frontal; lac, ‘lacrimal’; mx, maxilla; occ, occipital condyle; pal, palatine; palp, palpebral; par, parietal; pifor, pineal foramen; pmx, premaxilla; po, postorbital; pofr, postfrontal; prfr, prefrontal; proo, prootic; ps, parasphenoid; pt, pterygoid; sa, surangular; soc, supraoccipital; sq, squamosal; vom, vomer. Total skull length is approximately 2 metres.
Figure 4.
Premaxilla of Pliosaurus kevani n. sp. DORCM G.13,675 and contacting portions of the maxilla.
In dorsal (A), left lateral (B–C), ventral (D–E), and anterior (F) views. In line drawings (C, E) dark grey tone represents broken bone surface, mid grey represents matrix, and light grey represents tooth or artificial restoration. Abbreviations: for, foramen; mx, maxilla; mx1, first maxillary alveolus; pdp, paradental plates; pmx, premaxilla; pmx6, sixth premaxillary alveolus; pmx-mx, premaxilla-maxilla contact; pmx-pmx, premaxilla-premaxilla contact; vom, vomer. Scale bar equals 100 mm
Figure 5.
Cranium of Pliosaurus kevani n. sp. DORCM G.13,675 in ventral view.
In line drawing (B) dark grey tone represents broken bone surface, mid grey represents matrix, and light grey represents tooth or artificial restoration. Abbreviations: bat, basal tuber; cfps, cultriform process of the parasphenoid; ecto, ectopterygoid; exoc-opis, exoccipital-opisthotic; in, internal naris; jug, jugal; mx, maxilla; mx19, 19th maxillary alveolus; occ, occipital condyle; pal, palatine; pal-pt, palatine-pterygoid contact; palf, palatal fenestra; par, parietal; pmx, premaxilla; ps, parasphenoid; pt, pterygoid; soc (l), left portion of supraoccipital; sof, suborbital fenestra; sq, squamosal; vom, vomer; vom-pt, vomer-pterygoid contact. Scale bar equals 500 mm.
Figure 6.
Maxilla of Pliosaurus kevani n. sp. DORCM G.13,675 and contacting bones.
Schematic (A) showing the anterior and posterior portions of the maxilla figured in (B–E). Anterior portion in left dorsolateral (B) and ventral (D) views, and posterior portion in left dorsolateral (C) and right dorsolateral (E) views. Abbreviations: en, external naris; fr, frontal; fr-pmx, frontal, premaxilla contact; mx, maxilla; mx-pmx, maxilla-premaxilla contact; lac, ‘lacrimal’; lac-mx, ‘lacrimal’-maxilla contact; pdp, paradental plates; pmx, premaxilla; pmx-pmx, premaxilla-premaxilla contact; vom, vomer; vom-mx, vomer-maxilla contact. Scale bars equal 100 mm.
Figure 7.
Context of the ‘lacrimal’ of Pliosaurus kevani n. sp. DORCM G.13,675.
Left orbit and antorbital region in dorsolateral view (A), the unidentified bone fragment attached anterior to the orbit by matrix is not the same as the suborbital bar fragment in (B–D). Portion of possible suborbital bar fragment in medial or lateral (B, D) and dorsal (C) views. Abbreviations: jug, jugal; lac, ‘lacrimal’; ?lac-?jug, possible ‘lacrimal’-jugal contact; mx, maxilla; mx-lac, maxilla-’lacrimal’ contact; pifor, pineal foramen; sob, suborbital bar. Scale bars equal 100 mm (A) and 50 mm (B–D).
Figure 8.
Anterior portion of the right suborbital bar of Pliosaurus kevani n. sp. DORCM G.13,675.
In medial (A) and lateral (B) views. Abbreviations: jug, jugal; po, postorbital; sq, squamosal; sq-jug, squamosal-jugal contact. Scale bar equals 100 mm.
Figure 9.
Suspensorium of Pliosaurus kevani n. sp. DORCM G.13,675 in posterior view.
Posterior view of entire suspensorium (A), of the left ventral ramus (B), and of the squamosal-squamosal contact (C). Abbreviations: bat, basal tuber; occ, occipital condyle. Scales bar equal 100 mm (A) and 50 mm (B–C).
Figure 10.
Left orbit and postorbital region of Pliosaurus kevani n. sp. DORCM G.13,675 showing parietal crest in anterolateral view.
Abbreviations: exoc, exoccipital-opisthotic; pifor, pineal foramen; parcr, parietal crest; soc (l), left portion of supraoccipital; soc (r), right portion of supraoccipital. Scale bar equals 100 mm.
Figure 11.
Palate of Pliosaurus kevani n. sp. DORCM G.13,675 in the region of the internal naris, seen in ventral view.
Schematic (A) showing the portion of the palate figured in (B–C). (C) is at greater magnification than (B). Abbreviations: for, foramina; in, internal naris; pal, palatine; pal-max, palatine-maxilla contact; vom, vomer; vom-pal, vomer-palatine contact; vom-pt, vomer-pterygoid contact. Scale bars equal 100 mm.
Figure 12.
Posterior palate of Pliosaurus kevani n. sp. DORCM G.13,675.
Schematic (A) showing the portion of the palate figured in (B–D). Posterior portion of palate in ventral view with various regions shown at magnification (B–D). Abbreviations: cfps, cultriform process of the parasphenoid; piv, posterior interpterygoid vacuity; ps-pt, parasphenoid-pterygoid contact; sof, suborbital fenestra. Scale bars equal 200 mm (B) and 100 mm (C–D).
Figure 13.
Bones of the otic capsule of Pliosaurus kevani n. sp. DORCM G.13,675.
Schematic (A) showing the portions of the otic capsule figured in (B–D). Right portion of the supraoccipital in posterior (B), right ventrolateral (C) and right posterolateral (D) views. Schematic (G) showing the portions of the otic capsule figured in (E–F). Left exoccipital-opisthotic and articulated left portion of the supraoccipital in anteromedial (E) and ventral (F) views. Abbreviations: amp, ampullary recess in opisthotic; exoc, exoccipital; exoc-opis, exoccipital-opisthotic; exoc-soc, exoccipital-supraoccipital contact; exof, exoccipital facet of the supraoccipital; formag, supraoccipital portion of the foramen magnum; opis, opisthotic; paf, parietal facet of the supraoccipital; pop, parocipital process of the opisthotic; proof, prootic facet; pvc, posterior vertical canal; soc (l), left portion of the supraoccipital; soc (r), right portion of the supraoccipital; sq, squamosal. Scale bar equals 100 mm.
Figure 14.
Right exoccipital-opisthotic of Pliosaurus kevani n. sp. DORCM G.13,675.
In anterior (A), dorsal (B), posterior (C), ventral (D), anteroventral (E), and medial (F) views. Abbreviations: bof (exoc), exoccipital portion of the basioccipital facet; exoc, exoccipital; exoc-opis, exoccipital-opisthotic suture; opis, opisthotic; pop (opis), paroccipital process; pvc, posterior vertical canal; socf, supraoccipital facet of the exoccipital-opisthotic; XII, canal for the hypoglossal nerve opening into the metotic/jugular canal. Scale bar equals 50 mm (A–D) or 25 mm (E–F).
Figure 15.
Posterior part of the basicranium of Pliosaurus kevani n. sp. DORCM G.13,675.
In ventral (A) and posterior (B) views. Abbreviations: bat, basal tuber; occ, occipital condyle; par, parietal; ps, parasphenoid; pt, pterygoid. Scale bar equals 100 mm.
Figure 16.
Left mandible of Pliosaurus kevani n. sp. DORCM G.13,675.
In lateral (A–B) and medial (C–D) views. In line drawings (B, D) dark grey tone represents broken bone surface, mid grey represents matrix, and light grey represents tooth or artificial restoration. Abbreviations: ang, angular; ang-art, angular-articular contact; art, articular; cor, coronoid; den, dentary; for, foramina or foramen; gle, glenoid; neo, possible neomorphic ossification; pra, prearticular; retrart, retroarticular process; spl, splenial; sur, surangular. Scale bar equals 500 mm.
Figure 17.
Right mandible of Pliosaurus kevani n. sp. DORCM G.13,675.
In lateral (A–B) and medial (C–D) views. In line drawings (B, D) dark grey tone represents broken bone surface, mid grey represents matrix, and light grey represents tooth or artificial restoration. Abbreviations: ang, angular; aomc, anterior opening of Meckel's canal; art, articular; cor, coronoid; den, dentary; for, foramina or foramen; gle, glenoid; neo, possible neomorphic ossification; pra, prearticular; spl, splenial; sur, surangular. Scale bar equals 500 mm.
Figure 18.
Anterior preserved portions of the mandibles of Pliosaurus kevani n. sp. DORCM G.13,675.
Anterior portion of left mandible in dorsal (A), lateral (B), ventral (C), and medial (D) views. Anterior portion of right mandible in dorsal (E), lateral (F), and medial (G–H) views with magnification (x2.0) of the region posterior to the anterior opening of Meckel's canal (H). Abbreviations: ang, angular; aomc, anterior opening of Meckel's canal; cor, coronoid; cor-den, coronoid-dentary contact; cor-spl, coronoid-splenial contact; den, dentary; den5, fifth preserved dentary alveolus; den6, sixth preserved dentary alveolus; spl, splenial. Scale bar equals 200 mm.
Figure 19.
Central portions of the mandibles of Pliosaurus kevani n. sp. DORCM G.13,675.
Central portion of left mandible in dorsal (A) and medial (B) views. Central portion of right mandible in dorsal (C) and medial (D–E) views, showing an enlarged view of the possibly neomorphic ossification (E). Abbreviations: den-cor, dentary-coronoid contact; for, foramen; neo, possibly neomorphic ossification; pdp, paradental plates; pra, prearticular; spl, splenial; spl-cor, splenial-coronoid contact. Scale bars equal 200 mm (A–D) and 100 mm (E).
Figure 20.
Posterior portions of the mandibles of Pliosaurus kevani n. sp. DORCM G.13,675.
Posterior portion of the left mandible in dorsal (A) and lateral (B) views. Posterior portion of the right mandible in dorsal (C), lateral (D), posterodorsomedial (E), and medial (F, G, H) views with magnifications (x2.0) of the coronoid-surangular contact (G) and foramen at the splenial-angular contact (H). Abbreviations: ang, angular; cor, coronoid; cor-sur, coronoid-surangular contact; for, foramen or foramina; gle, glenoid; pra, prearticular; pra-ang, prearticular-angular contact; retrart, retroarticular process; spl, splenial; sur, surangular; sur-ang, surangular-angular contact. Scale bars equal 200 mm (A–D, F) and 100 mm (E).
Figure 21.
Teeth of Pliosaurus kevani n. sp. DORCM G.13,675.
Large tooth in mesial or distal (A, C), labial (B), lingual (D), and apical (E) views. Small tooth in labial (F), mesial or distal (G), and lingual (H) views. Scale bars equal 20 mm.
Figure 22.
Hypothetical reconstruction of the right symphysial dentition of Pliosaurus kevani n. sp. DORCM G.13,675.
Eight additional alveoli are reconstructed based on the estimated missing portion, and pattern of interlock with the preserved cranial teeth. The reconstructed alveoli are marked ‘+2’, ‘+3’ etc. A small mesialmost alveolus is not visible in lateral view. Scale bar equals 200 mm.
Table 1.
Selected measurements and observations on Late Jurassic pliosaurid specimens, arranged stratigraphically (older specimens are shown lower in the table).
Figure 23.
Phylogenetic position of Pliosaurus kevani n. sp. DORCM G.13,675.
Strict (A) and strict reduced (B) consensus topologies of >130000 shortest length trees 1336 steps long resulting from analysis of our matrix of 85 taxa and 270 characters modified from [26]. Shading is used to indicate major clades, Pliosauridae is enclosed by a grey rectangle, and Pliosaurus kevani n. sp. is indicated by an arrow.
Figure 24.
Maximum skull length of Jurassic–Cretaceous pliosaurids.
Silhouettes are only approximately indicative of body size and proportions.