Figure 1.
Geological and geographical setting of the fossil site.
(A) Fossil site (red star); (B) Geological formation of the Metangula graben (after [30]); (C) Stratigraphic correlation between the Mozambican and South African Karoo (after [30], [138]).
Figure 2.
ML1620 (Niassodon mfumukasi holotype) in ventral, dorsal and left lateral views.
Figure 3.
Niassodon mfumukasi 3D rendering, after segmentation of individual bones according to bone color code .(see methods section).
Ventral (A); dorsal (B); skull in ventral (C); posterior (D); lateral right (E); lateral left (F) views. dv, dorsal vertebrae; fe, femur; fm, foramen magnum; o, orbit; m, mandible; pg, pelvic girdle; pif, pineal foramen; ptf, post temporal fenestra; r, ribs; sco, sclerotic ossicles; st, stapes; sv, sacral vertebrae; tf, temporal fenestra.
Figure 4.
Preserved skeletal elements of Niassodon mfumukasi (ML1620) imposed on a Pristerodon silhouette, adapted from [146].
Skeletal parts repositioned are in dark grey. Skeletal parts mirrored from the other side are in light grey. Skeletal parts in the original position are in intermediate grey.
Figure 5.
Niassodon mfumukasi skull roof.
Ventral (A), dorsal (B), left lateral (C), anterodorsal (D) views. f, frontal; fo, frontal ornamentation; l, lacrimal; ld, lacrimal duct; n, nasal; nb, nasal boss; p, parietal; pdf, descending flange of the parietal; pf, prefrontal; pif, pineal foramen; po, postorbital; pof, postfrontal; pp, preparietal; ppc, preparietal crests.
Figure 6.
Left lateral (A), right lateral (B), ventral (C), dorsal (D), anterior (E), posterior (F) views. appmx, ascending process of the premaxilla; aprpt, anterior palatal ramus of the pterygoid; arept, ascending ramus of the epipterygoid; ch, choanae; cpmx, caniniform process of the maxilla; dpmx, dorsal process of the maxilla; ecpt, ectopterygoid; ept, epipterygoid; eptf, epipterygoid foot; icf, internal carotid foramen; iptv, interpterygoid vacuity; lpf, lateral palatal foramen; mppt, medium plate of the pterygoid; mt, maxillary teeth; mx, maxilla; mxa, maxillary antrum; pal, palatine; pals, palatine sulci; palv, palatine vacuity; pf, palatal foramen; pk, postcaniniform keel; pmx, premaxilla; ppmx, posterior process of the maxilla; psh, parashenoid; pshr, parashenoid rostrum; pt, pterygoid; qrpt, quadrate ramus of pterygoid; qrptf, quadrate ramus of pterygoid fragments; tb, tooth bub; v, vomer; vf, vascular foramina.
Figure 7.
Niassodon mfumukasi occipital region.
Right lateral (A), left lateral (B), dorsal (C), ventral (D), posterior (E), anterior (F) views. asqf, anterior left squamosal fragment; atl, parcial atalantal ring; bocc, basioccipital; dmlso, dorsal median lobe of the supraoccipital; dpsq, dorsal process of the squamosal; exocc, exoccipital; fm, foramen magnum; fo, fenestra ovalis; jf, jugular foramen; icgq, intercondylar groove of the quadrate; ip, interparietal (postparietal); laso, lateral ala of the supraoccipital; lqc, lateral condyle of the quadrate; mcq, medial condyle of the quadrate; occp, occipital pit; opot, opisthotic; p, parietal; prot, prootic; ptf, postemporal fenestra; q, quadrate; qj, quadratojugal; qpsq, quadrate process of the squamosal; so, supraoccipital; sq, squamosal; st, stapes; zpsq, zigomatic process of the squamosal.
Figure 8.
Niassodon mfumukasi internal cranial bones.
Right lateral (A), left lateral (B), dorsal (C), ventral (D), and anterior (E) view. ap, alar process of the prootic, bsh, basisphenoid; co, crista osophagea; ecpt, ectopterygoid; eppt, epipterygoid; eth, ethmoid; ethmv, ethmoid vacuity; f VII, facial foramen; itg, intertuberal groove; lb, lateral buttress; pal, palatines; palv, palatine vacuity; pal f, palatal foramen; pila, pila antotica of the prootic; psh, parasphenoid; pt, pterygoid; qrpt, quadrate ramus of the pterygoid; qrptf, quadrate ramus of the pterygoid fragments; stur, sella turcica; sco, sclerotic ossicles; smx, septomaxilla; v, vomer.
Figure 9.
Left lateral (A), right lateral (B), anterior (C), posterior (D), ventral (E), dorsal (F) views; right ramus in medial view (G) and left ramus in medial view (H). ang, angular; art-part, articular-prearticular complex; cpsang, conical process of the surangular; dt, dentary teeth; dta, dentary table; hy?, probable hyoid; mrart, median ridge of the articular; lds, lateral dentary shelf; pds, postdentary sulcus; rlang, reflected lamina of the angular; sang, surangular; spl, splenial; vksang,ventral keel of the surangular.
Figure 10.
Niassodon mfumukasi left dentary.
teeth in lateral (A), medial (B) and, dorsal (C) views. Part of the dentary was erased medially so that the teeth implantation can be seen. Note the presence of three replacement teeth medially located to the functional tooth row.
Figure 11.
Niassodon mfumukasi vertebral column.
Dorsal (A), right lateral (B), ventral (C) views. ana, atlas neural arches; aic, atlas intercentrum; c, caudal vertebra; dv, dorsal vertebra; poz, postzygapophysis; prz, prezygapophysis; s, sacral vertebra; sp, spinous processes.
Figure 12.
Niassodon mfumukasi caudal vertebra and atlas.
Caudal vertebra in dorsal (A), anterior (B), left lateral (C), posterior (D), anterodorsal (E), ventral (F) views and sagittal section (G); atlas intercentrum in ventral (H), anterior (I), dorsal (J), right lateral (K) views; left atlas neural arch in dorsal (L), medial (M), left lateral (N) views. af, articular facet; atp, atlas intercentrum transverse process; cn, neural canal; dec, dorsal excavation on the centrum; exoccf, exoccipital facet; la, lateral.
Figure 13.
Niassodon mfumukasi pelvic girdle. pip
, posterior iliac process; aip, anterior iliac process; ac, acetabulum; pu, pubis; il, ilium.
Figure 14.
SR∀CT virtual histological sections of the femur and partial pelvic girdle of Niassodon mfumukasi.
(A) Volume rendering of the femur and partial pelvic girdle; (B) Proximal epiphyseal section of the femur; (C) longitudinal section along the femur; (D) diaphyseal section of the femur and acetabulum (note that the femur is not in anatomical position, but as it was found in the fossil, i.e., the femur epiphysis is dislodged from the acetabulum).
Figure 15.
Niassodon mfumukasi neuroanatomy and inner ear anatomy.
Cranial endocasts in the cranium in dorsal (A), and left lateral (B) views. Cranial endocasts in dorsal (C), ventral (D), left lateral without the osseous labyrinth (E), left lateral view with the osseous labyrinth (F). Both osseous labyrinths in dorsal and anterior views (G) and both osseous labyrinths in right lateral view (H). aamp, ampulla of the anterior semicircular canal ca, carotid arteries; ascc, anterior semicircular canal; cc, crus comunis; ce, cerebelum; cn, cochlear nerve; cnI, olfactory nerve; cn VII, facial nerve; cn VIII, vestibulocochlear nerve; cnIX-XI, glossopharyngeal and vagoaccessory nerves; cnXII, hypoglossal nerves; en, epiphyseal nerve; fb, forebrain; fl, paraflocculus; is, isthmus; hscc, horizontal semicircular canal; hy, hypophysis; LOL, left osseous labyrinth; mo, medula oblongata; lag, lagena; ob, olfactory bulb; ot, olfactory tract; pamp, ampulla of the posterior semicircular canal; pflex, pontine flexure pscc, posterior semicircular canal; ROL, right osseous labyrinth; vcm + cn V, vena capitis medialis and trigeminal nerve; vcd, vena capitis dorsalis; vn, vestibular nerve.
Figure 16.
Most parsimonious cladogram from the phylogenetic analysis.
Scores: 999.866 steps, consistency index = 0.240, retention index = 0.711. Numbers at nodes represent decay index (left/top), symmetric resampling (middle), and the percentage of the 463,436 suboptimal trees in which the node is resolved (right/bottom). Niassodon mfumukasi in bold.
Brain volume to body mass plot in different tetrapod clades.