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| Schleitheimia schutzi
Rauhut, Holwerda & Furrer, 2020
Illustration: Beat Scheffold.
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Abstract
Although sauropodomorph dinosaurs have been known for a long time from the Late Triassic of central Europe, sauropodomorph diversity and faunal composition has remained controversial until today. Here we review sauropodomorph material from the Canton Schaffhausen, Switzerland. The material comes from three different but geographically close localities and represents at least three different taxa. Apart from the common genus Plateosaurus, the material includes remains of two different large, robustly built sauropodomorphs. One of these is described as a new taxon, Schleitheimia schutzi n. gen. et sp., on the basis of an unusual ilium and associated axial and appendicular material. Schleitheimia represents a derived basal sauropodiform and possibly the immediate outgroup to Sauropoda, and thus is the most derived sauropodomorph known from the Late Triassic of Europe. These results thus highlight the diversity of sauropodomorphs in the Late Triassic of central Europe and further indicate widespread sauropodomorph survival across the Triassic-Jurassic boundary.
Keywords: Late Triassic, Switzerland, Sauropodomorpha, Sauropod origins
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| Posterior cervical vertebra of Schleitheimia schutzi n. gen., n. sp., PIMUZ A/III 538. a, b left and right lateral views; c dorsal view; d anterior view; e posterior view; f ventral view.
aas, anterior articular surface; na, neural arch; ld, lateral depression; nc, neural canal; pap, parapophysis; vk, ventral keel; vlr, ventrolateral ridge. Scale bar equals 5 cm
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Systematic palaeontology
Dinosauria OWEN, 1842.
Sauropodomorpha HUENE, 1932.
Sauropodiformes SERENO 2007 (sensu McPhee et al. 2014).
Schleitheimia n. gen.
Type species. Schleitheimia schutzi sp. nov.
Etymology. Genus name refers to the type locality at Schleitheim, Canton Schaffhausen, Switzerland.
Schleitheimia schutzi sp. nov.
Etymology. Species epithet honours the collector of the type material, Emil Schutz (1916–1974).
Holotype. PIMUZ A/III 550, partial right ilium.
Type locality and horizon. The type locality is Santierge (Fig. 1), a hill situated 900 m south of the church of Schleitheim in the Swiss Canton Schaffhausen (47° 44′ 30″ N, 8° 29′ 13″ S). The material, collected in the Bratelen Bonebed (“Rhät-Bonebed”), was most probably derived from the uppermost part of the ‚Zanclodonmergel‘(= Knollenmergel), now called Gruhalde Member of the Klettgau Formation, uppermost Norian (Jordan et al. 2016).
Diagnosis. The new taxon can be diagnosed by the following autapomorphies: medial brevis shelf of ilium developed as dorsoventrally broad, rounded ridge just below the mid-height of the iliac blade on the medial side that ends in a large, round expansion at the posterior end of the ilium; fourth trochanter of the femur very robust and arises gradually out of the posterior surface of the bone at about its mid-width towards its apex at the posteromedial margin; crista tibiofibularis of the femur exceptionally broad and only very slightly offset medially from the lateral margin of the shaft, so that no posteriorly facing shelf is present lateral to the crista.
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| Time-calibrated cladogram of basal sauropodomorph relationships (based on the unweighted analysis), showing the survival of numerous lineages (including sauropods) across the Triassic-Jurassic boundary |
Conclusions:
Fragmentary sauropodomorph remains from the probably Late Norian of Schaffhausen, Switzerland, that were long considered to represent the common central European genus Plateosaurus can be shown to represent a separate taxon of non-sauropodan sauropodomorphs, Schleitheimia schutzi. The recognition of this new taxon, together with an evaluation of other sauropodomorph material from the Late Triassic of Schaffhausen shows that at least three different basal sauropodomorph taxa were present in the Norian of Switzerland. Schleitheimia is a derived sauropodiform and might even represent the immediate outgroup to sauropods. In the context of a phylogenetic analysis, the new taxon indicates that the Triassic/Jurassic extinction event probably only had a minor effect on sauropodomorph evolution, and that the ascent of sauropods was delayed until the late Early Jurassic, when other basal sauropodomorph lineages perished in the Pliensbachian/Toarcian extinction event and gave way to an explosive radiation of that clade.
Oliver W. M. Rauhut, Femke M. Holwerda and Heinz Furrer. 2020. A derived Sauropodiform Dinosaur and other Sauropodomorph Material from the Late Triassic of Canton Schaffhausen, Switzerland. Swiss Journal of Geosciences [Swiss J Geosci]. 113, 8. DOI: 10.1186/s00015-020-00360-8
