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

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. http://zoobank.org/urn:lsid:zoobank.org:pub:02C69A1C-FCC8-4D0C-BA71-79BA30BC9DA7 SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP 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.