Comparison of the geographic distribution of Hyaenodontidae (top) and Hyainailouridae (bottom).

<p>White: no fossils recorded; Grey: limited diversity; Black: main radiation.</p

Occipital view of the skull of <i>Kerberos langebadreae</i> gen. & sp. nov. (holotype, MNHN.F.EBA 517).

<p>A, occipital view. B, drawing of the occipital view. Abbreviations: F. M., foramen magnum; Lamb. Cr., lambdoid crest; Oc., occipital; Oc. C., occipital condyle; Oc. Cr., occipital crest; P. Gl. Pr., postglenoid process; Par. Ap., paroccipial apophysis; Sag. Cr., sagittal crest; Sq., squamosal.</p

Stratigraphic repartition of the different subfamilies of specialized carnivorous mammals in Europe during the Paleocene and Eocene, with special attention to hyainailourines.

<p>The new taxon described here, <i>Kerberos langebadreae</i>, is in bold. Note that currently i. the stratigraphic extension of <i>Paroxyaena pavlovi</i> during Priabonian is unknown [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0135698#pone.0135698.ref008" target="_blank">8</a>] and ii. the age of <i>Parapterodon</i> is unknown but is estimated to be late Priabonian [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0135698#pone.0135698.ref009" target="_blank">9</a>]. Stratigraphic scale, eustatic curve, and isotopic curves produced with TSCreator [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0135698#pone.0135698.ref010" target="_blank">10</a>] from the data compiled by Gradstein et al. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0135698#pone.0135698.ref011" target="_blank">11</a>]. Abbreviations: ELMA, European Land Mammal Ages; MP, Mammal Palaeogene.</p

Drawings of the skull of <i>Kerberos langebadreae</i> gen. & sp. nov. (holotype, MNHN.F.EBA 517).

<p>A, dorsal view; B, ventral view; C, left lateral view; D, right lateral view. Abbreviations: Al., alisphenoid; An. C. F., anterior condyloid foramen; Bas., basisphenoid; F. M., foramen magnum; F. Ov., foramen oval; Fr., frontal; Inc. F., incisive foramen; Infr. F., infraorbital foramen; J., jugal; La., lacrimal; Mas. Ap., mastoid apophysis; Mas. Par. Ap., mastoid-paroccipital apophysis; Mas. Pr., mastoid process; Max., maxilla; Na., nasal; Oc. C., occipital condyle; Oc., occipital; Op. F., optic foramen; P. Gl. Pr., postglenoid process; Pa., parietal; Pal., palatine; Par. Ap., paroccipial apophysis; Po. F., posterior pterygoid foramen; Pr. Gl. Pr., preglenoid process; Premax., premaxilla; Sag. Cr., sagittal crest; Sq., squamosal; To. Pal., torus palatinus.</p

Comparison of the skull in ventral view of Hyaenodontidae (left) and Hyainailouridae (right).

<p>See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0135698#pone.0135698.t001" target="_blank">Table 1</a> for description of the numbered features. Left: skull of <i>Sinopa grangeri</i> redrawn after Matthew ([<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0135698#pone.0135698.ref055" target="_blank">55</a>], <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0135698#pone.0135698.g005" target="_blank">Fig 5</a>); right: skull of <i>Apterodon macrognathus</i> redrawn after Szalay ([<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0135698#pone.0135698.ref057" target="_blank">57</a>]; <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0135698#pone.0135698.g007" target="_blank">Fig 7</a>).</p

Consensuses of the second phylogenetic analysis of the hyainailourines with <i>Leakitherium</i> excluded.

<p>A: strict consensus (120 steps long; CI 0.59; RI 0.75) of the second phylogenetic analysis of the hyainailourines which includes body size character with indications of the Bremer support values. B: relationships among several hyainailourines in the majority rule consensus (117 steps long; CI 0.60; RI 0.76) with percentages of presence of the clades among equally parsimonious trees. In bold: <i>Kerberos langebadreae</i> gen. & sp. nov.</p

Comparison of the cranial features of Hyaenodontidae and Hyainailouridae.

<p>Comparison of the cranial features of Hyaenodontidae and Hyainailouridae.</p

Upper dentition of <i>Kerberos langebadreae</i> gen. & sp. nov. (holotype, MNHN.F.EBA 517).

<p>A, right maxilla bearing P¹ and P⁴-M³ in occlusal view. B, left maxilla bearing P²-M³ in occlusal view.</p

Consensuses of the first phylogenetic analysis.

<p>A: strict consensus (135 steps long; CI 0.52; RI 0.68) of the first phylogenetic analysis of the hyainailourines which includes body size character with indications of the Bremer support values. B: relationships among several hyainailourines in the majority rule consensus (120 steps long; CI 0.59; RI 0.75) with percentages of presence of the clades among equally parsimonious trees. In bold: <i>Kerberos langebadreae</i> gen. & sp. nov.</p

Mandible of <i>Kerberos langebadreae</i> gen. & sp. nov. (MNHN.F.EBA 518).

<p>A-C; MNHN.F.EBA 518a, left hemimandible bearing canine, M₂-M₃; A, occlusal view; B, lingual view; C, labial view. D-F, MNHN.F.EBA 518b, right hemimandible bearing P₃-P₄ and M₂-M₃; D, labial view; E, lingual view; F, occlusal view.</p