Alvarezsauridae gen. et sp. indet., ZIN PH 2444/16, left manual phalanx II-1, in distal (a), proximal (b), medial (c), dorsal (d), lateral (e), and ventral (f) views.

<p>Dzharakuduk, Uzbekistan; Bissekty Formation, Upper Cretaceous (Turonian). Abbreviations: lcn, lateral condyle; lco, lateral cotyle; mco, medial cotyle; mcn, medial condyle. Scale bar equals 1 mm.</p

Alvarezsauridae gen. et sp. indet., carpometacarpus.

<p>Dzharakuduk, Uzbekistan; Bissekty Formation, Upper Cretaceous (Turonian). <b>a-d</b>, ZIN PH 2440/16, right carpometacarpus, in proximal (<b>a</b>), ventral (<b>b</b>), dorsal (<b>c</b>), and distal (<b>d</b>) views. <b>e-h</b>, ZIN PH 2443/16, left carpometacarpus, in proximal (<b>e</b>), ventral (<b>f</b>), dorsal (<b>g</b>), and distal (<b>h</b>) views. Abbreviations: cf, central facet; icg, intercondylar groove; lc, lateral condyle; mc, medial condyle; mf, medial facet; mcII, metacarpal II; mcIII, metacarpal III; mcIV?, possible metacarpal IV; s, suture between metacarpals II and III. Scale bars equal 1 mm.</p

A new lepidosauromorph reptile from the Middle Triassic (Ladinian) of Germany and its phylogenetic relationships

<p>Although lepidosaurs are by far the most diverse and widespread group of present-day nonavian reptiles, with over 10,000 formally named species, their early diversification is documented only by a handful of incomplete fossils with few diagnostic features. Recent excavations in strata of the Lower Keuper (Middle Triassic: Ladinian) of Baden-Württemberg, Germany, have yielded abundant skeletal remains of a diversity of small- to medium-sized diapsid reptiles, which include at least three taxa of lepidosauromorphs. One, here named <i>Fraxinisaura rozynekae</i>, is a small-bodied reptile characterized by (1) maxillary and dentary tooth crowns conical, with lingual striae near their apices; (2) maxilla with a dorsoventrally low facial process and long tooth-bearing portion anterior to this process; (3) jugal with a short anterior process and a very short, pointed posterior process; and (4) ilium with a tall, posterodorsally extending blade. Tooth implantation is pleurodont. Size variation in the sample sheds some light on ontogenetic changes, mainly affecting the shape of and ornamentation on cranial bones. Phylogenetic analysis recovered <i>Fraxinisaura rozynekae</i> among Lepidosauromorpha and as the sister taxon of the Middle to Late Jurassic <i>Marmoretta oxoniensis</i>. Unfortunately, currently existing character-taxon matrices do not allow confident resolution of the interrelationships of these and other early Mesozoic lepidosauromorph reptiles.</p> <p><a href="http://zoobank.org/urn:lsid:zoobank.org:pub:02C69A1C-FCC8-4D0C-BA71-79BA30BC9DA7" target="_blank">http://zoobank.org/urn:lsid:zoobank.org:pub:02C69A1C-FCC8-4D0C-BA71-79BA30BC9DA7</a></p> <p>SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at <a href="http://www.tandfonline.com/UJVP" target="_blank">www.tandfonline.com/UJVP</a></p> <p>Citation for this article: Schoch, R. R., and H.-D. Sues. 2018. A new lepidosauromorph reptile from the Middle Triassic (Ladinian) of Germany and its phylogenetic relationships. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2018.1444619.</p

<i>Elachistosuchus huenei</i> MB.R. 4520 (holotype).

<p>A, B, segmented skull bones in A, left and B, right lateral views. Maxilla in orange, jugal in blue, ventral process of postorbital in purple, frontal-nasal complex in green, prefrontal in yellow, piece of bone that is here identified as a broken and displaced part of prefrontal. Scale bar equals 2 mm. C, D, segmented bones of the palate in C, dorsal and D, left lateral views. Vomers and anterior portions of palatine in purple, main body of left palatine in light blue, pterygoids and posterior part of palatines in green, ectopterygoid in gray, parabasisphenoid in yellow, and epipterygoid in dark blue. Scale bar equals 2.5 mm. Red lines indicate breaks along sutures between palatal elements. E, string of articulated trunk vertebrae in left lateral view. Scale bar equals 3 mm. F, G, left mandibular ramus in F, lateral and G, medial views. Coronoid in orange, dentary in purple, surangular in dark blue, angular in light blue, articular in green, prearticular in yellow, and splenial in red. Scale bar equals 2.5 mm. G-I, left side of the braincase in G, posterior and slightly lateral, H, left lateral and I, dorsal views. Braincase bones in green, inner ear structures in yellow. Scale bar equals 1 mm. J, segmentation of articulated trunk vertebrae (anterior to the left). K, ventral view of elements of the pectoral girdle. Interclavicle and clavicles in gray, scapula in purple, and unidentified elements in green. Scale bar equals 2.5 mm. Abbreviations: an, angular; ar, articular; asc, anterior semicircular canal; cl, clavicle; co, coronoid; d, dentary; ec, ectopterygoid; eo, exoccipital; ep, epipterygoid; cp, cultriform process; f, frontal; fo, fenestra ovalis; icl, interclavicle; j, jugal; m, maxilla; ltf, lower temporal fenestra; lsc, lateral semicircular canal; mf, metotic foramen; or, orbit; op, opisthotic; pa, prearticular; pl, palatine; po, postorbital; pop, paroccipital process; pr, prootic; prf, prefrontal; ps, parabasisphenoid; psc, posterior semicircular canal; pt, pterygoid; sa, surangular; sc, scapula; so, supraoccipital; sp, splenial; v, vomer.</p

Tooth implantation in <i>Elachistosuchus huenei</i> MB.R. 4520 (holotype).

<p>Cross-sections of maxilla (A1 and A4; scale bars equal 0.35 mm) and dentary (A2, A3, and A5; scale bars equal 0.3 mm) teeth with respective planes of section indicated on the skull in left lateral view. B1-2, sagittal sections of B1, maxillary and B2, dentary tooth rows. Scale bars equal 0.75 mm.</p

"Allcompat" consensus tree from the Bayesian analysis using the character-taxon matrix of Ezcurra <i>et al</i>. [13] with <i>Elachistosuchus huenei</i> included.

<p>Numbers indicate the posterior probabilities of branches. Nodes without number indicate a posterior probability of 1.</p

"Allcompat" consensus tree from the Bayesian analysis using the character-taxon matrix of Chen <i>et al</i>. [12] with <i>Elachistosuchus huenei</i> included.

<p>Numbers indicate the posterior probabilities of branches. Nodes without number indicate a posterior probability of 1.</p