Turiasauria-like teeth from the Upper Jurassic of the Lusitanian Basin, Portugal

Abstract

Turiasauria is a clade of eusauropods with a wide stratigraphic range that could extend from the Bathonian to the lower Aptian including Turiasaurus, Losillasaurus, Zby and putatively, Galveosaurus, Atlasaurus and isolated remains from Middle Jurassic-to-Lower Cretaceous. Some are characterised by the presence of heart-shaped teeth. Several tooth occurrences from the Portuguese Upper Jurassic with this type of morphology (SI: 1.1-1.8) are reported and discussed. If this morphology is regarded as synapomorphic of Turiasauria, the teeth will be tentatively related to this clade. From a sample of 43 teeth, three main morphotypes are described. Three hypotheses might explain the morphological variation: (1) the range of tooth morphologies indicates variation in the jaw, (2) the range of tooth morphologies indicates taxonomic variation or (3) a combination of both. The general wear pattern in morphotypes I and II starts with a distal facet, then the appearance of mesial/apical facet and finally a 'V'-shaped facet. In morphotype III, the wear begins with a mesial facet. The variability observed for Portuguese Upper Jurassic specimens is congruent with the morphological variability along the tooth row shown by other sauropods with spatulate/spoon-shaped teeth and it is considered the most parsimonious hypothesis to explain it.

Upper Jurassic sauropod record in the Lusitanian Basin (Portugal): Geographical and lithostratigraphical distribution

“…The known and the new occurrences put in evindece a relatively high potential for future dis-12 coveries in this area, However, the so far published (Mocho et al, 2012(Mocho et al, , 2016b and unpublished material of sauropods only allows identification of indeterminate sauropods and eusauropods, possibly members of Turiasauria, and indeterminate macronarians. The presence of several compressed cone-chisel teeth in the sedimentary sequence suggests the presence of macronarian forms within the clade formed by Europasaurus + Titanosauriformes (Figure 6.2).…”

“…This new information suggests a more diverse scenario for sauropod fauna during the Late Jurassic of the Lusitanian Basin than previously considered, with the identification of a clade previously unidentified in this basin, the non-neosauropod eusauropod group Turiasauria. Royo-Torres et al (2006) suggested the presence of Turiasauria in the Portuguese Upper Jurassic record, and this hypothesis was subsequently corroborated by the presence of new teeth and postcranial material (Mateus, 2009;Royo-Torres et al, 2009;Ortega et al, 2010;Mocho et al, 2012;Royo-Torres et al, 2014a;Mocho et al, 2016b). Four taxa, so far exclusively, were described in the Upper Jurassic of the Lusitanian Basin: the camarasaurid Lourinhasaurus alenquerensis (Lapparent and Zbyszewski, 1957;Dantas et al, 1998;Mocho et al, 2014b); the diplodocid Dinheirosaurus lourinhanensis (Bonaparte and Mateus, 1999;Mannion et al, 2012; recently referred as Supersaurus lourinhanensis by Tschopp et al, 2015), the basal macronarian and putative brachiosaurid Lusotitan atalaiensis (Lapparent and Zbyszewski, 1957;Antunes and Mateus, 2003;Mannion et al, 2013), and the turiasaur Zby atlanticus .…”

“…Several new occurrences have also been reported (Antunes and Mateus, 2003;Mateus, 2005;Royo-Torres et al, 2006;Yagüe et al, 2006;Mateus, 2009;Royo-Torres et al, 2009;Ortega et al, 2010;Mannion et al, 2012;Mocho et al, 2012Mocho et al, , 2013aMocho et al, , 2013bMateus et al, 2014;Mocho et al, 2014aMocho et al, , 2016bMocho et al, , 2017. This new information suggests a more diverse scenario for sauropod fauna during the Late Jurassic of the Lusitanian Basin than previously considered, with the identification of a clade previously unidentified in this basin, the non-neosauropod eusauropod group Turiasauria.…”

“…Sauvage (1897-98) and Lapparent and Zbyszewski (1957) also reported some localities with dinosaur remains near Vila Nova de Ourém and Porto de Mós (probably from the Alcobaça Fm.). Two teeth, one had a heart-shaped morphology probably referrable to Turiasauria (Figure 5.6-7, MG 16;Mocho et al, 2012Mocho et al, , 2016b) and other had a compressed cone-chisel-shaped morphology ( Figure 5.1, MG 8779) common in Titanosauriformes, but also found in the basal macronarian Europasaurus (Sander et al, 2006;Carballido and Sander, 2014). A posterior caudal vertebra (MMPM.P/554) from an indeterminate sauropod was also found in Fonte do Oleiro (Alcobaça Fm.…”

“…No sauropod remains were reported there, however (Lapparent and Zbyszewski, 1957). Several teeth were collected in this coastal area, corresponding to different morphotypes: i) heart-shaped teeth , tentatively referred to Turiasauria (see RoyoTorres and Upchurch, 2012;Royo-Torres et al, 2009;Mocho et al, 2012Mocho et al, , 2016b; ii) spatulate teeth (Figure 7.9-10; unpublished material housed in MG and SHN) referred to an indeterminate eusauropod (probably a macronarian); and iii) compressed cone-chisel-shaped teeth (unpublished material housed in the SHN), referred to Macronaria. The first of these morphotypes is the most abundant in this coastal sector.…”