ORIGINAL PAPER Lindwurmia, a new genus of Plesiosauria (Reptilia: Sauropterygia) from the earliest Jurassic of Halberstadt, northwest Germany Peggy Vincent 1,2 & Glenn W. Storrs 3 Received: 2 March 2018 /Accepted: 21 December 2018 # Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract This paper offers a re-description of one of the oldest (Lower Hettangian, Lower Jurassic) plesiosaurians (Reptilia: Sauropterygia) from Germany and discusses its phylogenetic relevance. Lindwurmia thiuda, new genus and species, is a moderately sized plesiosaur (estimated size between 2 and 3 m long) exhibiting several plesiomorphic features. Although it presents a short and robust premaxillary rostrum, constricted at the premaxilla–maxilla suture as observed in Rhomaleosauridae, its skull and skeleton share a great number of characters with basal sauropterygians and basal plesiosaurians: premaxillae and maxillae in contact posterior to the external nares, absence of contact between the vomers and the maxillae posterior to the internal nares, cervical zygapophyses wider than the vertebral centrum width and curved anterior border of the humerus. Phylogenetic analyses variably place Lindwurmia as sister taxon to Anningasaura and in a basal position to all other plesiosaurians or recover it among rhomaleosaurids. Most of the oldest plesiosaurians are known from the Hettangian or Hettangian-possibly Sinemurian strata of the UK (Lyme Regis and Street); Lindwurmia thus represents one of the oldest European taxa found outside of the UK. Keywords Germany . Hettangian . Lower Jurassic . Lindwurmia . Plesiosauria Abbreviations NHMUK Natural History Museum, London, UK OUMNH Oxford University Museum of Natural History, Oxford, UK LEICS New Walk Museum, Leicester, UK SMH Städtisches Museum Halberstadt, Museum Heineanum, Germany SMNS Staatliches Museum für Naturkunde, Stuttgart, Germany Introduction Germany has yielded many excellently preserved specimens of Plesiosauria (e.g. Maisch and Rucklin 2000;O’Keefe 2004; Großmann 2007). Most are from the Posidonien-Schiefer de- posits (Toarcian) of Baden-Württemberg, and very few are older (e.g; Westphaliasaurus simonsensii Schwermann and Sander 2011 ; partial remains of an undetermined plesiosaurian, Sachs et al. 2014). The specimen SMH (Städtisches Museum Halberstadt, Museum Heineanum, Germany) uncatalogued described here is the oldest plesiosaurian reported from Germany (Halberstadt, Saxony- Anhalt) with Rhaeticosaurus mertensi (Wintrich et al. 2017). Other specimens from northern Germany are known but come from more recent strata (e.g. Brancasaurus Wegner 1914; Gronausaurus Hampe 2013; Lagenanectes Sachs et al. 2017; Stumpf 2016). SMH uncatalogued was referred to Communicated by: Robert Reisz Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00114-018-1600-y) contains supplementary material, which is available to authorized users. * Peggy Vincent peggy.vincent@mnhn.fr Glenn W. Storrs gstorrs@cincymuseum.org 1 CR2P, MNHN–CNRS–Sorbonne Université, CP38, 57 rue Cuvier, 75005 Paris, France 2 Staatliches Museum für Naturkunde, Rosenstein 1, 70191 Stuttgart, Germany 3 Cincinnati Museum Center, Geier Collections & Research Center, 1301 Western Avenue, Cincinnati, OH 45203, USA The Science of Nature (2019) 106:5 https://doi.org/10.1007/s00114-018-1600-y