A large sized megalosaurid (Theropoda, Tetanurae) from the late Jurassic of Uruguay and Tanzania

Journal Pre-proof A large sized megalosaurid (Theropoda, Tetanurae) from the late Jurassic of Uruguay and Tanzania Matías Soto, Pablo Toriño, Daniel Perea PII:

S0895-9811(19)30505-X

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https://doi.org/10.1016/j.jsames.2019.102458

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SAMES 102458

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Journal of South American Earth Sciences

Received Date: 1 October 2019 Revised Date:

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Please cite this article as: Soto, Matí., Toriño, P., Perea, D., A large sized megalosaurid (Theropoda, Tetanurae) from the late Jurassic of Uruguay and Tanzania, Journal of South American Earth Sciences (2020), doi: https://doi.org/10.1016/j.jsames.2019.102458. This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Published by Elsevier Ltd.

A LARGE SIZED MEGALOSAURID (THEROPODA, TETANURAE) FROM THE LATE JURASSIC OF URUGUAY AND TANZANIA 1

Matías Soto1*, Pablo Toriño1 and Daniel Perea1 Instituto de Ciencias Geológicas, Facultad de Ciencias, Iguá 4225, 11400, Montevideo, Uruguay

ABSTRACT We report the first Jurassic remains that can confidently be referred to a megalosaurine theropod in Uruguay and Tanzania. This identification is sustained on a detailed morphological study. The large size of both teeth (>70 mm in lateral teeth) and denticles (<7 denticles per 5 mm), the clearly visible braided enamel texture, the centrally placed and apically restricted mesial carina in mesial teeth, and general shape of the teeth strongly resembles Torvosaurus. This is coherent with multivariate analyses of two datasets of large theropod teeth measurements, and also with the results of a phylogenetic analysis of theropod teeth. The presence of Torvosaurus in the Tacuarembó Formation of Uruguay further strengthens the Late Jurassic age proposed for the fossiliferous horizon. The Uruguayan megalosaurid would represent the apex predator in the vertebrate assemblage. The occurrence of megalosaurids in the Late Jurassic of Uruguay (the first unquestionable megalosaurid from South America) and Tanzania also greatly expands the geographical range of the family. Keywords. Theropoda; Megalosauridae; teeth; multivariate analysis; phylogenetic analysis; Uruguay; Gondwana *Corresponding author

INTRODUCTION Theropod teeth are common components of Mesozoic continental deposits, although knowledge is strongly biased towards Cretaceous theropods from Laurasia (e.g. Currie et al., 1990; Fiorillo & Currie, 1994; Baszio, 1997; Fiorillo & Gangloff, 2001; Sankey et al., 2001, 2002; Smith et al., 2005). In South America, teeth descriptions also mainly come from Cretaceous units (e.g. Medeiros, 2006; Candeiro & Tanke, 2008; Canale et al., 2009; Gianechini et al., 2011; Candeiro et al., 2012; Lindoso et al., 2012; Tavares & Santucci, 2014; Hendrickx et al., in press). Few theropods are known from Late Jurassic deposits in South America. These include the basal tetanuran Pandoravenator fernandezorum (Rauhut & Pol, 2017) plus isolated teeth from the Cañadón Calcáreo Formation of Argentina (Rich et al., 1999), the aberrant basal tetanuran Chilesaurus diegosuarezi (Novas et al., 2015) and fragmentary tetanuran remains from the Toqui Formation of Chile (Salgado et al., 2008), and isolated teeth from the Tacuarembó Formation of Uruguay (Perea et al., 2003, 2009), some of them belonging to ceratosaurids (Soto & Perea, 2008). Moreover, Late Jurassic theropod tracks are known from the Guará Formation of Brazil (Francischini et al., 2015), several units from Chile (Rubilar-Rogers et al., 2012 and references therein) and again the Tacuarembó Formation (Mesa & Perea, 2015). There are few other Late Jurassic theropod assemblages from Gondwana known so far. Goodwin et al. (1999) reported a few teeth from the Mugher Mudstone Formation of Ethiopia, proposing affinities to AcroCanthosaurus and Dromaeosaurinae, although we do not found evidence to sustain these determinations. Serrano-Martínez et al. (2015, 2016) described several teeth from the Tiourarén Formation, originally considered as Early Cretaceous in age but later reinterpreted as Middle/Late Jurassic by Rauhut & López-Arbarello (2009). Serrano-Martínez et al. (2015, 2016) referred their teeth to ceratosaurids, megalosaurids, allosaurids and possible spinosaurids (we found totally unconvincing the evidence for the latter referral, but this is beyond the scope of this paper). The best known Late Jurassic theropod assemblages in Gondwana is that of the Tendaguru Formation, including skeletal remains from Elaphrosaurus bambergi, described by Janensch (1920) and redescribed and identified as a noasaurid by Rauhut & Carrano (2016). Moreover, the carcharodontosaurid Veterupristisaurus milneri was described by Rauhut (2011), as well as fragmentary remains of probable ceratosaurids, abelisauroids, probable abelisaurids and basal tetanurans (Rauhut, 2005, 2011). Regarding isolated theropod teeth from the Tendaguru Formation, some of them were named by Janensch (1920) as Labrosaurus stechowi and Megalosaurus ingens, and others were generically referred to coelurosaurs (in the sense the term had in that time). ‘Labrosaurus’ stechowi has been regarded as a ceratosaurid theropod (Madsen & Welles, 2000; Soto & Perea, 2008; Rauhut, 2011), although one of the teeth has been recently reinterpreted as a spinosaurid (Buffetaut, 2013), again without convincing evidence. The gigantic teeth named ‘Megalosaurus’ ingens has been regarded as a ceratosaurid (Rowe & Gauthier, 1990) or a probable carcharodontosaurid (Rauhut, 2011). Herein we reinterpret is as belonging to a megalosaurid theropod, particularly Torvosaurus. The aim of this work is to describe in detail recently found theropod teeth from Uruguay, identify them to the lowest possible taxonomic level, test the referral with multivariate and phylogenetic analyses, and discuss the biostratigraphic, biogeographic and paleobiological implications.

Anatomical abbreviations. bld, basolingual depression. dc, distal carina. is, indeterdenticular sulcus. mc, mesial carina. pc, pulv cavity. tu, transverse undulations. Institutional abbreviations. BMNH, British Museum of Natural History, London, United Kingdom. FC-DPV, Facultad de Ciencias, Montevideo, Uruguay. MCF-PVPH, Museo Carmen Funes, Plaza Huincul, Argentina. MB, Museum für Naturkunde, Berlin, Germany. MGT, Museo de Geociencias de Tacuarembó, Tacuarembó, Uruguay. MPEFPV, Museo Paleontológico Egidio Feruglio, Trelew, Argentina. SGM Din, Ministere de l´Energie et des Mines, Rabat, Morocco. Measurements and ratios. Measurements and ratios (see Table 1) follow Smith et al. (2005), Van der Lubbe et al. (2009) and Hendrickx et al. (2015a). AL, apical length. CH, crown height. CBL, crown base length. CBW, crown base width. CBR, crown base ratio. CHR, crown height ratio. CWR, crown width ratio (new). CAA, crown apical angle. CDA, crown distal angle. CMA, crown mesial angle. DA, distoapical denticle count. DB, distobasal denticle count. DC, distocentral denticle count. DDL, distal denticle lenght. LAF, labial flutes. LIF, lingual flutes. MA, mesioapical denticle count. MB, mesiobasal denticle count. MC, mesiocentral denticle count. MCL, mid-crown length. MCR, mid-crown ratio. MCW, mid-crown width. MDL, mesial denticle lenght. MSL, mesial serrated carina length. MA, MB, MC and MSL could not be measured in Uruguayan specimens due to lack of preservation of mesial denticles. GEOLOGICAL SETTING The Tacuarembó Formation (Bossi, 1966) crops out in northern Uruguay, and comprises mainly whitish, yellowish and reddish, fine to medium grained, quartzofeldpathic sandstones. Common sedimentary structures are horizontal bedding, crossbedding and ripples. Some thin levels and lenses of green, red and violet pelites are ocassionally interbedded. Two members have been recognized since Bossi et al. (1975). The lower Batoví Member (Late Jurassic-?Neocomian), represents fluvial and aeolian deposition, and the upper Rivera Member (Neocomian), comprises exclusively aeolian deposits under hyperarid environment (Perea et al., 2009). Only the Batoví Member has yielded fossils so far. A few small to medium-sized theropod teeth have been reported elsewhere (Perea et al., 2003; Soto & Perea, 2008; Perea et al., 2009), but large theropod teeth have never been reported. Most of the teeth in this contribution were found in Cantera Bidegain or Bidegain Quarry (a locality first mentioned by Soto et al., 2012; Fig. 1), the most promising fossil site of the Tacuarembó Formation. The teeth figured in Figs. 2-5 were found in a 1-1.5 m thick, laterally extensive stratum of silty sandstones (Fig. 1A) which also yielded thousands of isolated ganoid scales, dozens of rather complete coelacanth bones and a few crocodyliform teeth and dipnoan tooth plates (Soto et al., 2012; Soto, 2016; Toriño et al., 2018). Several lines of evidence suggest rapid burial of the remains, such as the structureless character of the sandstones, close association of coelacanth cranial bones (most of them belonging to the same individual, which allowed to reconstruct a nearly complete Mawsonia skull; Toriño et al., 2018), articulated ganoid scales, good preservation of the delicate dipnoan bones still attached to the tooth plates, and the position of the tooth figured in Fig. 2, found stuck vertically (i.e., perpendicular to the stratum base and top; Fig. 1B) in the sandstone instead of lying horizontally (i.e.parallel to the stratum base and top). The remaining materials come from other localities: one tooth fragment from Martinote and one tooth from Los Rosanos (see Perea et al., 2001, 2003; Soto & Perea,

2008, 2010 for locality information). For general geological setting and detailed facies analysis of the unit, see Perea et al. (2009) and Bochi et al. (2019), respectively. METHODOLOGY Theropod teeth were examined under a Nikon SMZ 800 binocular lens. An enamel fragment removed from one of the teeth was gold-coated and analysed with a JEOL JSM-5900 LV scanning electron microscope (SEM). The most complete tooth was scanned with a 3D scanner Next Engine Ultra HD; the result of the renderization can be found at https://data.mendeley.com/datasets/6kntxfp449/1. Measurements and ratios (see Table 1 and SOM 1) follow Smith et al. (2005), van der Lubbe (2009) and Hendrickx et al. (2015a). We define herein a new variable, Crown Width Ratio (CWR), defined as CH/CBW, which is another way to express tooth elongation from that of Smith et al. (2005)’s Crown Height Ratio (CHR). It is the elongation of the tooth in mesial/distal view, instead of labial/lingual view. Tyrannosaurus and derived carcharodontosaurids, for instance, have very similar CHR (mean around 1.96 in both cases) but different CWR (means of 2.85 in Tyrannosaurus and 3.86 in derived carcharodontosaurids), given that the former possess incrassate (pachydont; Hendrickx et al., 2015a) teeth and the latter blade-like (ziphodont) teeth. Other large theropods show CHR values slightly lower (e.g. mean of 1.88 in Ceratosaurus) or higher (e.g. means of 2.20 in Genyodectes and 2.29 in Torvosaurus) than Tyrannosaurus and derived carcharodontosaurids, but again, CWR values are rather different (means of 4.13 in Ceratosaurus, 4.36 in Genyodectes and 4.58 in Torvosaurus). We also advocate for future works the need of using a simpler and at the same time informative way to express denticle size, using not MAVG and DAVG (i.e., mesial and distal average denticle densities, respectively) as Smith et al. (2005) did, nor MC and DC (mesial or distal counts at mid-carinae), but the minimum denticle density (i.e., the maximum denticle size) that can be assessed independently of the location in the carinae (usually between the center and the apex of the crown). We call this new variables Minimum Mesial Denticle Density (MMDD) and Minimum Distal Denticle Density (MDDD), and propose to redefine Rauhut & Werner (1995)’s Denticle Size Difference Index as MMDD/MDDD instead of MAVG/DAVG. This has the potential to maximize separation of theropods in which denticle size increase above the middle of the crown (e.g. megalosaurids). Moreover, measuring denticle densities at the apex (MA and DA), middle (MC and DC) and base (MB and DB) of the crown requires the carina to be perfectly preserved throughout the crown, a fact that is rarely observed in the Uruguayan material. Although it can be useful for descriptive purposes, its inclusion in multivariate analyses would drastically reduce the size of the database. Large theropod teeth database (hereafter LTTD) used in this paper is based on that published by Hendrickx et al. (2015b). Given that we want to test the affinities of ziphodont teeth, teeth of other morphologies were deleted, including conidont (spinosaurids) and pachydont (tyrannosauroid) teeth, besides the very different temporal and geographic context of the latter. Theropods that were represented by less than three teeth, such as Berberosaurus and Piatnitzkysaurus, were also removed, given that three is the minimum number of cases in order to graphically represent a polygon. Three teeth from the carcharodontosaurine Tyrannotitan were measured by the first author and included in the LTTD. In the original LTTD (Hendrickx et al., 2015b – Supplementary Online Material 4), Torvosaurus is represented by only four teeth. In order to increase the number of cases for this taxon, we added to the LTTD another four Torvosaurus

teeth measured by Hendrickx et al. (2015b – Supplementary Online Material 5), as well as numerous Torvosaurus teeth reported by Malafaia et al. (2017). The modified LTTD includes 257 teeth (https://data.mendeley.com/datasets/5j4n53zmck/1). A principal component analysis (PCA), a discriminant analysis (DA) and two cluster analyses (CA), UPGMA and Neighbour Joining, were performed, using the software PAST 3.12 (Hammer et al., 2001). Only crown size variables (AL, CH, CBL, CBW) plus denticle densities at mid-carina (MC and DC) were taken into account. Thus, shape variables (CBR, CHR, CWR, CAA, CMA, CDA) are only given for descriptive purposes. Analyses were performed on log-transformed variables to approach a normal distribution. In both cluster analyses an Euclidean similarity index was used, and final branch was chosen as a root in the case of Neighbour Joining, following Hendrickx et al. (2019). Twelve a priori groups were defined. Ungrouped teeth intended to be classified by the DA include three lateral teeth from Uruguay. We also included a tooth (FUB PB Ther 1) from the Late Jurassic of Portugal described by Rauhut & Kriwet (1994). It was referred to Torvosaurus gurneyi by Hendrickx & Mateus (2014a) but this referral was never tested using multivariate nor phylogenetic analyses. Finally, we added two teeth of the enigmatic large theropod ‘Megalosaurus’ ingens from the Late Jurassic of Tanzania, one of them (MB R 1050) is the holotype described by Janensch (1920, 1925) and Rauhut (2011), and the other (BMNH R6758) is a still undescribed cast. In MB R 1050, variables CH, CBL, CBW and DC were cited by Janensch (1925), although we cannot asure that he measured these variables exactly as proposed by more recent authors. AL had to be measured on the photograph published by Rauhut (2011), and to reduce the error it was compared to already known CH and CBL measurements. DDL was estimated as 5/DC. In BMNH R6758, all measurements were kindly provided by C. Hendrickx (pers. com., 2019). A second row of analyses (PCA, DA and two CA) were performed using the recently published `personal dataset´ (Young et al., 2009), restricted to large theropods, including 377 teeth (https://data.mendeley.com/datasets/wj3kzsvdd9/1). Fifteen a priori groups were defined. The use of two datasets is not redundant given that Young et al. (2009) included several new variables (LAF, LIF, MCL, MSW, MSL, MDL, DDL. Analyses were again performed on log-transformed data. A log(x+1) correction was applied to LAF and LIF to account for zero flutes, as performed by Young et al. (2019). Finally, a phylogenetic analysis on a matrix of 145 characters and 99 taxa (https://data.mendeley.com/datasets/8vp43836t5/1) related to teeth and jaw bones (Young et al., 2019, an improvement of that of Hendrickx & Mateus, 2014b) was performed, using a constrained topology as described by these authors. As a search method, traditional search was selected, perturbing Wagner trees with 100 replications, using tree bisection reconnection as swapping algorithm, and keeping 10 trees per replication. The ‘enforce constraints’ options was turned on. The script WSTATS was ran to obtain consistency and retention indexes.

SYSTEMATIC PALEONTOLOGY THEROPODA Marsh, 1881 TETANURAE Gauthier, 1986 MEGALOSAUROIDEA (Fitzinger, 1843) Walker, 1964 MEGALOSAURIDAE Fitzinger, 1843 MEGALOSAURINAE (Fitzinger, 1843) Paul, 1988

TORVOSAURUS Galton & Jensen, 1979 TORVOSAURUS sp. Figs. 2-7 Materials. We refer to this taxon FC-DPV 2343, FC-DPV 2971, FC-DPV 2972, MGT-1139, MGT-1184, MGT-1204, plus several fragments deposited in the MGT. Other specimens include MGT-142 (originally described as Theropoda gen. et sp. indet. by Perea et al., 2003) and the tooth fragment FC-DPV 1951. Among Tanzanian material, some of the specimens figured by Janensch (1925, pl. IX-8 to IX-10) share the features of the Uruguayan material. Besides the holotype of ‘Megalosaurus’ ingens, MB R 1050, Rauhut (2011) listed MB R 1053, 1054, 1057, 1058, 1060, 1061, 1064, 1067, 1069, and 1082, although pending first hand examination we cannot assure that effectively all these teeth belong to this taxon. Provenance. The Uruguayan material come from the Batoví Member (Late Jurassic?Neocomian) of the Tacuarembó Formation. MGT-142 was found in Los Rosanos, FCDPV 1951 in Martinote and the remaining specimens in Bidegain Quarry. The Tanzanian material come from several specimen of the Lower, Middle and Upper Saurian members (Janensch, 1925; Rauhut, 2011), which according to Bussert et al. (2009) can be dated as ?Callovian-middle Oxfordian, late Kimmeridgian and Tithonian, respectively. Description. The lateral tooth FC-DPV 2971 is the most complete specimen (Fig. 2). It is one of the largest teeth known for the unit (CH = 77.00 mm), strongly labiolingually compressed (CBR = 0.45), rather elongate (CHR = 2.33 and CWR = 5.13), with a moderately curved distal border (Fig. 3A, C) and an oval basal crosssection, although the presence of two depressions (a labial and a lingual one) in the transition from the crown to the upper root gives an ‘8’-shaped appearance (Fig. 3E). The enamel in the region of the mesial carina is worn off, and thus the degree of development of this carina as well as mesial denticle size and density is unknown. However, we infer that the carina extended near the base due do the pattern of wear, which is similar to that seen for instance in spinosaurid theropods (Benton et al., 2000; Milner & Kirkland, 2007). In distal view, the distal carina is slightly sigmoidal (Fig. 2D), with a gentle concavity towards the lingual face. The distal carina does preserve denticles. They are very coarse (DC = 7; Fig. 3A), and exhibit long and well developed interdenticular sulci, inclined towards the base of the crown (Fig. 3B). The enamel shows faint transverse undulations, particularly in the labial side. The enamel also presents a submilimetric veined texture visible to the naked eye, comprising short, parallel crests with apicobasal orientation (Fig. 3C). The unerupted tooth fosa in the upper root appears as a shallow concavity in the lingual side. The lateral tooth MGT-1139 is not well preserved, due to heavy wear of the tip, but when complete is would have exceeded CH = 80 mm. Despite the enamel being removed in both carinae, judging from the base of distal denticles they were very coarse (DC = 5). The lateral tooth FC-DPV 2972 is also not well preserved, lacking the enamel entirely in the labial face. The lingual face is slightly mesiodistally concave, giving the teeth a bean-shaped cross-sectional outline, a fact that may be enhanced due to slight crushing. It is slightly stouter than FC-DPV 2971 (CBR = 0.50 and CWR = 4.72), and thus a more mesial position in the maxilla or dentary is inferred. Enamel is lacking from the mesial carina, as in the teeth described above. The distal carina preserves the base of

the denticles, which are very coarse (DC = 6). The carina shows the same slight sigmoidal shape that in FC-DPV 2971. FC-DPV 2343, another lateral teeth, is heavily eroded at the apex an does not preserve the distal carina nor most of mesial carina, but it is important because if the single lateral tooth that preserved the base of the latter, allowing to confirm that it extended to the cervix (Fig. 4A). This is in contrast with the restricted development of mesial carinae in mesial teeth (see below). Denticle density measured at the base of this carina (MB) is 10. FC-DPV 2343 shows very conspicuous and closely packed transverse undulations (Fig. 4B) in both faces of the crown. The undulations are also visible in the preserved portion of the upper root. MGT-1184 (Fig. 5) is considerably stouter, with a subcircular basal cross-section, and lacks any distal curvature, and thus it is interpreted as a tooth from either the premaxilla or the tip of the dentary. The enamel in the region of the mesial carina is removed, but at least it can be seen that the carina did not reach the base of the crown, occupying roughly 75% of the crown (Fig. 5B). The lingual side of the tooth lacks grooves or ridges. Only the lower half of the distal carina preserves denticles (Fig. 5D), which are rather coarse (density of 8 measured below the center of the carina), although not as coarse as in FC-DPV 2971 or FC-DPV 1139. The enamel is similar to that of FCDPV 2971, but in addition it shows transverse undulations in the lingual face (Fig. 5A). MGT-142 (Fig. 6) is a tooth of mesial position (CBR = 0.71), either from the right dentary or the right premaxilla, due to the orientation of the apical wear facet. It is elliptic in basal cross-section. It was originally described by Perea et al. (2003). It shows a short mesial carina, restricted to the apical third of the tooth, and thus is similar to MGT-1184. The mesial carina ends abruptly, instead of showing a gradual decreasing in size of the denticles. The distal carina follows the midline (differing from FC-DPV 2971 and 2972). Denticles are rather coarse: MB = 10 and DC = 9 (although given that the tip is heavily worn it should be measured slightly above the center of the preserved tooth, increasing the density to 8). The lingual side of the tooth lacks grooves or ridges. To sum up, the large size of the teeth, the coarseness of the denticles and the enamel ornamentation allow to identify even tooth fragments. This is the case of FC-DPV 1951 (Fig. 7), a partial distal carina ca. 27 mm long, still embedded in a sandstone matrix. Twenty denticles are preserved, being rather coarse (DC = 7), with well developed interdenticular sulci (which suggest the presence of another ten denticles) inclined towards the inferred tooth base (Fig. 7). At least the preserved part of the distal carina is straight. Denticles are in the same plane that the remainder of the crown fragment, suggesting a strongly labiolingually compressed tooth. FC-DPV 1951 completes the information on denticle morphology, the apices of which are broken in the remaining materials. Denticles are elongated (the proximodistal length being three times the apicobasally width), with expanded apices which show a symmetrically convex apical edge (Fig. 7). In distal view they are not chisel-like, but rather labiolingually broad. Each denticle has an apicobasal lenght of ca. 0.60 mm, while the interdenticular space measures ca. 0.13 mm. Macroscopically, every three denticles the termination of wide enamel transversal undulations can be appreciated (Fig. 7B), similar to the ornamentation of MGT-1184 and FC-DPV 2343, although given the incomplete nature of the specimen we cannot completely rule out the possibility that they represent marginal undulations (as first suggested by Soto, 2010). The submilimetric texture of the enamel is similar to that present in the teeth described so far, although with a more ‘pitted’ appearance (Fig. 7). Comparisons. Only a few theropods shows lateral teeth with CH larger than 70 mm: the ceratosaurid Ceratosaurus, the megalosaurids Torvosaurus and Wiehenvenator (Fig.

7C, D), the spinosaurid Spinosaurus, the carcharodontosaurids Acrocanthosaurus, Carcharodontosaurus (Fig. 7G, H), Giganotosaurus and Mapusaurus, and the tyrannosaurids Tyrannosaurus¸ Albertosaurus, Daspletosaurus, Tarbosaurus and Zhuchengtyrannus (e.g. Britt, 1991; Bakker, 2000; Rauhut, 2004; Smith, 2005; Smith et al., 2005; Coria & Currie, 2006; Hendrickx et al., 2015b; Rauhut et al., 2016; Malafaia et al., 2017; Table 2), as well as ‘Megalosaurus’ ingens (Janensch, 1920, 1925; Rauhut, 2011). Spinosaurids and tyrannosaurids can be easily ruled out given their conidont and pachydont dentitions (sensu Hendrickx et al., 2015a), respectively. The sigmoidal shape in distal view has been frequently mentioned for Carcharodontosaurinae (Coria & Currie, 2006; Hone & Rauhut, 2009; Fig. 8H) and certain megalosaurids, such as Afrovenator and Torvosaurus (Hendrickx & Mateus, 2014b; Hendrickx et al. 2015b; Malafaia et al., 2017; Fig. 8D), but is also present in the neovenatorid Fukuiraptor (Currie & Azuma 2006), the basal megalosauroid Condorraptor (M.S., pers. obs. in MPEF-PV 1695) and teeth described as ‘Megalosaurus’ ingens (pers. obs. in BMNH R6758; Fig. 9D). A submilimetrical, well-visible braided enamel texture strongly recalls the condition in megalosaurids (Hendrickx & Mateus, 2014b; Hendrickx et al. 2015b), although it is present in other large theropods such as ceratosaurids, carcharodontosaurids and tyrannosaurids (Hendrickx & Mateus, 2014b). Well developed interdenticular sulci are present in several large theropods (Table 2), such as abelisaurids, megalosaurids, Allosaurus, carcharodontosaurids and tyrannosaurids (Currie et al., 1990; Abler, 1992; Fiorillo & Currie, 1994; Rauhut & Kriwet, 1994; Azuma & Currie, 2000; Smith, 2007; Hendrickx & Mateus, 2014b; Hendrickx et al., 2014), as well as ‘Megalosaurus’ ingens (Rauhut, 2011). Within megalosaurids, they are especially well developed in Torvosaurus (Fig. 8F) and some Megalosaurus teeth (Hendrickx et al., 2014, 2015b; Malafaia et al., 2017). Transverse undulations are present in several theropods, such as megalosaurines, tyrannosauroids, large Allosaurus specimens and Dromaeosaurus (e.g. Brusatte et al., 2007; Benson, 2008, 2010; Hendrickx & Mateus, 2014b; Hendrickx et al. 2015b). Transverse undulations are absent in the only known Afrovenator tooth (Hendrickx et al., 2015b). We interpreted the variable degree of development of transverse undulations in the Uruguayan materials (absent, present in one face, present in both labial and lingual faces, tenuous or well visible, loosely or closely packed) as product of intraspecific or individual variation, e.g. due to different enamel deposition rates. Similar features have been observed in other reptile groups, such as metriorhynchid crocodilyforms (Pol & Gasparini, 2009; de Andrade et al., 2010), with similar degree of variation (D. Pol, pers. comm., 2016). Wrinkles (i.e., marginal undulations sensu Hendrickx et al., 2015a), originally believed to diagnose carcharodontosaurids (Sereno et al., 1996), were later shown to be more extended within Theropoda (Table 2), including the abelisaurid Skorpiovenator (Canale et al., 2009), the megalosaurids Afrovenator, Megalosaurus and Torvosaurus (Hendrickx et al., 2015b; Malafaia et al., 2017), the spinosaurid Irritator (Sues et al., 2002), and the allosauroids Fukuiraptor (Azuma & Currie, 2000) and Allosaurus (Brusatte et al., 2007), as well as ‘Megalosaurus’ ingens (Rauhut, 2011). However, differences do exist: the most conspicuous wrinkles are still related to Carcharodontosaurus saharicus (Fig. 8G, H), being subtler in other carcharodontosaurids as Mapusaurus and C. iguidiensis (Brusatte et al., 2007). Wrinkles in some Megalosaurus teeth are obliquely directed towards the base of the crown (Hendrickx et al., 2015b). Wrinkles in the only known Afrovenator tooth are less conspicuous, shorter, not obliquely directed and related to the mesial carina only

(Hendrickx et al., 2014). Although clear wrinkles have not been observed in the material figured herein (the only possible exception being FC-DPV 1951), Megalosaurus-like obliquely directed wrinkles related to the distal carina do exist in an incomplete tooth from the Tacuarembó Formation (MGT-1140). However, this tooth is considered different from the other Uruguayan materials described herein due to the considerably smaller size of both the crown and the denticles. The absence of lingual grooves in mesial teeth is a clear difference from ceratosaurid teeth described in the same unit (Soto & Perea, 2008). A denticle density of less than 7 (Table 2) is only found in Torvosaurus and the tyrannosaurids Tyrannosaurus, Zhuchengtyrannus and probably Tarbosaurus (Smith, 2005; Smith et al., 2005; Hone et al., 2011; Hendrickx et al., 2015b - Supplementary Online Material 3; C. Hendrickx, pers. com., 2019), as well as ‘Megalosaurus’ ingens (Janensch, 1925; Rauhut, 2011). A denticle density of 5 is only seen in Torvosaurus, particularly below the apex of the tooth (Hendrickx & Mateus, 2014b; Hendrickx et al. 2015b; Malafaia et al., 2017) and ‘Megalosaurus’ ingens (Janensch, 1925; Rauhut, 2011). The upper end of the denticle density range (8) is recorded in several large theropods such as Tyrannosaurus, Carcharodontosaurus, Allosaurus and Torvosaurus. Denticles that increase in size toward the apex is a common trait in megalosaurid theropods (Hendrickx & Mateus, 2014b; Hendrickx et al. 2015b – Supplementary Online Material 6), although a comprehensive research is needed to assess its presence in other theropod taxa. Distal denticle shape in FC-DPV 1951 strongly recalls the morphology in megalosaurines (Fig. 8F) as figured by Hendrickx & Mateus (2014b) and Hendrickx et al. (2015b), as well as other large theropod taxa (e.g. see Hendrickx & Mateus, 2014b). The basal cross-section of the best preserved crown (FC-DPV 2971) is similar to that described in diverse theropods such as Allosaurus, Afrovenator, Dromaeosaurus and Torvosaurus (Currie et al., 1990; Bakker, 2000; Sankey et al., 2002; Hendrickx et al., 2014). Overall, the teeth from Tacuarembó belonged to a large-sized theropod, with CH around 80 mm, labio-lingual compression from low (CBR around 0,7 in mesial teeth) to moderate (CBR = 0,45-0,51 in lateral teeth), important elongation in lateral teeth (CWR up to 5,13), basal cross-section subcircular/elliptic (mesial teeth) to oval/8-shaped shaped (lateral teeth), enamel ornamented with straight parallel ridges visible to the naked eye (and also, in certain teeth, with macroscopic transverse undulations in one or two faces), mesial carina not extending to the base of the crown (in mesial teeth), distal carina gently sigmoidal in lateral teeth, very coarse denticles (DC = 5-8), subequal mesial and distal denticles (DSDI around 1), and well developed interdenticular sulci inclined towards the base of the crown. Comment on ‘Megalosaurus’ ingens. One tooth-based taxon from Western Gondwana strongly resembles the Uruguayan specimens. Janensch (1920, 1825) described several teeth from the Lower, Middle and Upper Saurian members of the Tendaguru Formation (Late Jurassic of Tanzania; Bussert et al., 2009) as ‘Megalosaurus’ ingens (Figs. 8I, J, 9). The teeth have been described by Janensch (1920, 1925) and Rauhut (2011). There is no reason to assign these remains to Megalosaurus, nor to Ceratosaurus as Rowe & Gauthier (1990) did. In fact, Carrano et al. (2012) considered it as an indeterminate tetanuran. Rauhut (2011) considered ‘C’. ingens teeth resemble those of carcharodontosaurids, represented in the Tendaguru Formation by skeletal material. However, denticle size in carcharodontosaurids is considerably lower than in ‘C’. ingens. Morever, not all Tanzanian material show Carcharodontosaurus-like marginal undulations, nor all carcharodontosaurids have

marginal undulations. We consider megalosaurine affinities to me be more likely. The only apparently conflicting character (mesial carinae reaching the cervix in lateral teeth) is now documented in some Torvosaurus teeth (Malafaia et al., 2017; C. Hendrickx, pers. com., 2019), as also reflected in the coding of the corresponding character for Torvosaurus in Young et al. (2019). The very large size of the teeth (even larger than the Uruguayan material, surpassing 10 cm in crown height; Fig. 8I, 9), denticle shape and size (reaching density values as low as 5, i.e. one denticle per mm; Fig. 8J), as well as the general shape of the Tanzanian teeth, immediately recall the Uruguayan material described above (compare Fig. 8A-C with Fig. 8I,J and 9) and we propose herein that it belong to the same taxon of megalosaurine theropod, Torvosaurus. MULTIVARIATE ANALYSES In order to test how similar are the Uruguayan teeth to the Tanzanian specimens, and which large theropod taxon they resemble more, a PCA and DA were performed. Only reasonably complete teeth were considered. Hence, heavily worn teeth such as the mesial teeth MGT-142 and MGT-1184 or the lateral teeth FC-DPV 2343 were excluded, because their CH and AL are underestimated or unknown. Besides, recently defined variables like MCL, MCW and MSL were not originally measured in this teeth. Two rounds of analyses were performed, the first one employing the modified LTTD of Hendrickx et al. (2015b) and the second one using the ‘personal dataset’ (excluding small theropod teeth) of Young et al. (2019). Results can be accesed at https://data.mendeley.com/datasets/5j4n53zmck/1 https://data.mendeley.com/datasets/wj3kzsvdd9/1 respectively.

and

Principal component analysis 1 A PCA was performed from the correlation matrix, prior to the DA, in order to test taxon separation with a simplified number of variables. The two first principal components (PC) explain 87.90% of the observed variability (PC1 70.92% and PC2 16.98%). Size variables allow to distinguish several theropod taxa along the x-axis (e.g. relatively smaller theropods such as neovenatorids and abelisaurids to the left, larger theropods such as carcharodontosaurids and Torvosaurus to the right), while MC and DC are useful to provide further separation along the y-axis (Fig. 10A). FUB PB Ther 1 and the Uruguayan teeth fall clearly inside the Torvosaurus morphospace. The Tanzanian teeth plot immediately outside the Torvosaurus morphospace but far from other theropods. It has to be mentioned that FC-DPV 2971 also falls in the Carcharodontosaurine morphospace, given that there is some overlap with the Torvosaurus morphospace (Fig. 10A). Cluster analysis (UPGMA) 1 All teeth are grouped with Torvosaurus teeth. The Tanzanian teeth group together, and the Uruguayan teeth group together with the Portuguese tooth. The clusters also include some teeth from others theropods, particularly carcharodontosaurids (Fig. 11A). Cluster analysis (Neighbour Joining) 1 The results are very like to those obtained with UPGMA (Fig. 12A; see above). Discriminant analysis 1

When a DA using only size variables of the LTTD, plus DC, is performed the first two axis explain 80.25% of the variance. Variables which better explain the variability in theropod teeth are AL and CH (first canonical axis) and MC and DC (second canonical axis). The hit ratio was rather low (64.31%), and is only artificially increased when shape variables are usen along with size variables, as discovered by other authors (Soto, 2010; Hendrickx et al., 2015b). As with the PCA, FUB PB Ther 1 and the Uruguayan teeth fall clearly inside the Torvosaurus morphospace (Fig. 13A). The Tanzanian teeth plot again immediately outside the Torvosaurus morphospace but far from other theropods. FC-DPV 2971 falls this time in the boundary of the Carcharodontosaurine morphospace, given that there is less overlap with the Torvosaurus morphospace than in the PCA. All teeth are classified as Torvosaurus by the DA (Table 4), which is coherent with the morphological interpretation. Principal component analysis 2 This second PCA was also performed from the correlation matrix. The two first principal components (PC) explain 74.29% of the observed variability (PC1 53.87% and PC2 20.43%). Variability along the x-axis (PC1) is strongly influenced positively by size variables such as CBW, CH, AL and CBL. LAF/LIF and MDL/DDL influences positively and negatively variability along the y-axis (PC2), respectively. The plot is not so clear due to the inclusion of highly apomorphic theropod teeth (i.e., spinosaurids), resulting in a compression of data of the remaining teeth (Fig. 10B). Moreover, this results in some overlap in the region of the largest theropods such as Tyrannosauridae, Carcharodontosaurinae, basal Ceratosauria and Torvosaurus. For this reason, each tooth has to be considered separately. MGT-1139 plots in the Tyrannosaurid morphospace but not far from basal Ceratosauria, Torvosaurus and Carcharodontosaurinae. FC-DPV 2972 plots in a region where there is overlap among Torvosaurus, Tyrannosauridae and Carcharodontosaurinae. FC-DPV 2971 plots in the tyrannosaurid and carcharodontosaurine morphospaces, but not far from Torvosaurus. MB R 1050 plots in the Carcharodontosaurinae morphospace and in the boundary of Tyrannosauridae. Finally, BMNH R6758 plots outside all morphospaces, the closer ones being Tyrannosauridae, Torvosaurus and Carcharodontosaurinae. Cluster analysis (UPGMA) 2 The Tanzanian teeth are grouped together, along with Tyrannosaurus teeth, while the Uruguayan teeth are also grouped together, this time with a Megalosaurus tooth (Fig. 11B). Cluster analysis (Neighbour Joining) 2 The Tanzanian teeth are grouped together, along with carcharodontosaurine and Torvosaurus teeth. FC-DPV 2971 joins a larger cluster, which besides the taxa already mentioned include a few tyrannosaurids and another Torvosaurus tooth. FC-DPV 2972 is grouped with a Megalosaurus teeth, while MGT-1139 is grouped with a Mapusaurus tooth, within a larger group of tyrannosaurid teeth (Fig. 12B). Discriminant analysis 2 In this second DA the first two axis explain only 68.55% of the variance. LIF/LAF and MDEL/DDL influence strongly negatively and positively the first canonical axis, respectively, whereas variables such as CBW, CH, AL influence strongly positively the

second canonical axis. Variables which less explain the variability in theropod teeth are CA (whichf, being a ratio, can e safely excluded from future analysis) and MSL. The hit ratio was rather low (60.80%). As with the second PCA, there is overlap among morphospaces of Tyrannosauridae, Carcharodontosaurinae, basal Ceratosauria and Torvosaurus (Fig. 13B). BMNH R6758 plot outside all morphospaces, but very close to the boundary of the Carcharodontosaurine morphospace and not far from the morphospaces of Torvosaurus and basal Ceratosauria (and the boundary of Tyrannosauridae). The other Tanzanian tooth, MB R 1050, plots in a different position, in the morphospaces of Tyrannosauridae and basal Carcharodontosauridae and immediately outside the morphospace of Carcharodontosaurinae, but nof far from Torvosaurus, Megalosauridae and basal Ceratosauria. Concerning the Uruguay teeth, FC-DPV 2971 plot in the basal Ceratosauria morphospace (but close to its boundary), close to the boundary of Carcharodontosaurinae and not far from Torvosaurus and the boundary of Tyrannosauroidea. MGT-1139, in turn, plot in the morphospaces of Torvosaurus, Tyrannosauridae and Carcharodontosauridae, and close to the boundary of basal Ceratosauria. Finally, FC-DPV 2972 plot in the morphospaces of Torvosaurus, Tyrannosauridae, Carcharodontosaurinae and basal Ceratosauria, but in the two first cases close to the boundaries (Fig. 13B). Regarding classifications, FC-DPV 2971 and FC-DPV 2972 are classified as basal ceratosaurians, MGT-1139 and MB R 1050 as Torvosaurus, and BMNH R6758 as a carcharodontosaurine (Table 4). Overall, taking into account the results of the first round of PCA, CA and DA there can be little doubt that both the Uruguayan and Tanzanian teeth should be assigned to Torvosaurus. Moreover, they demonstrate that the referral by Hendrickx & Mateus (2014) of FUP PB Ther 1 to Torvosaurus was correct. The results of the second round of analyses is not so clear, given similarities to basal ceratosaurians, carcharodontosaurines and tyrannosaurids. An increase in the number of Torvosaurus teeth would probably leave most in not all teeth well inside the corresponding morphospace, as in the first PCA and DA. It is also desirable to increase the sample of both Uruguayan and Tanzanian teeth in order to improve the results of multivariate analysis. Excluding taxa which have unique morphologies (i.e. conidont dentition of Spinosauridae, pachydont dentition of Tyrannosauridae) and very different temporal and geographic contexts (which is clearly the case of Tyrannosauridae) is another way to obtain clearer plots and, more important, to not incur in missclasifications. PHYLOGENETIC ANALYSIS The phylogenetic analysis yielded 4 most parsimonious trees (MPTs) of 1221 steps, with CI = 0.211 and RI = 0.458. The consensus tree (Fig. 14) retrieved the Uruguayan theropod (scored combined the material described herein) and the Tanzanian theropod (scored as a combination of MB R 1050 and BMNH R6758) in a polytomy with Torvosaurus and Megalosaurus, confirming the proposed placement within Megalosaurinae and a close relationship with Torvosaurus. The number of MPTs, tree length and indexes do not change if additional characters states are added for crown height in lateral teeth (>9 cm in Tyrannosaurus, Carcharodontosaurus, Giganotosaurus, Acrocanthosaurus, Torvosaurus, ‘Megalosaurus’ ingens, Spinosaurus and the Uruguayan theropod, the latter two judging from fragmentary teeth) and number of mesial denticles per 5 mm at 2/3 of the carina (<7 in Tyrannosaurus, Torvosaurus

and ‘Megalosaurus’ ingens) and number of distocentral denticles per 5 mm (<7 in Tyrannosaurus, Torvosaurus, ‘Megalosaurus’ ingens and the Uruguayan theropod). Several dental characters strongly support this clade. The eight synapomorphies are: lateral teeth with CH equal or higher than 6 cm (character 69.2) and an average number of mid-crown denticles on distal carina equal or higher than 8 (character 88.3), short and poorly developed interdenticular sulci between apical denticles on the mesial carina (character 107.1), long and well-developed interdenticular sulci on the distal carina, both between mid-crown denticles (character 108.2) and basalmost denticles (character 109.2), pronounced large transversal undulations on the crown in some lateral teeth (character 112.2), short marginal undulations in some lateral teeth (character 114.1), and clearly visible braided enamel surface texture (character 120.2). DISCUSSION Based on the large size (CH > 70 mm) and the number of denticles on the carina (<7 denticles/5 mm), these isolated teeth could belong to a large-bodied theropod from the families Megalosauridae, Carcharodontosauridae or Tyrannosauridae (Tables 2 and 3). However, based on the morphology of the mesial teeth (mesial carina facing mesially and extending at a certain level from the cervix) and lateral teeth (distal carina centrally positioned on the distal surface of the crown), and the braided enamel surface texture, all crowns are confidently referred to Megalosauridae. Among this clade, only Torvosaurus shows less than 7 denticles/5 mm on the distal carina. In addition, both Torvosaurus and the material from Uruguay share well-developed interdenticular sulci, transverse/marginal undulations on the crowns and an oval to 8-shaped cross-section oultine at the crown base. For the same reasons, the materials from Tanzania should also be referred to Torvosaurus. Although they may represent the same taxon due to geographical proximity, based on teeth only they do not share any derived character to distinguish them from the described species of the genus, T. tanneri and T. gurneyi. Among theropod teeth from Germany described by Gerke & Wings (2016), Morphotype A clearly comprises Torvosaurus teeth, as confirmed by multivariate analyses performed by these authors. However, Gerke & Wings (2016) referred the teeth to Megalosauridae, and not Torvosaurus, due to the development of the mesial carina in lateral teeth. As already said above, this condition is now documented in Torvosaurus. Biostratigraphical and biogeographical implications Megalosaurids are known from Middle to Late Jurassic units from United States, Europe, China and Niger hitherto (Fig. 15A). The results of this contribution allow to extend the geographic range of the family (compared Fig. 15B and 15C). The presence of megalosaurids in South America and Africa is not surprising, given the absence of large geographical barriers in the Jurassic, the presence of the Middle Jurassic basal megalosauroids Piatnitzkysaurus floresi (Bonaparte, 1979) and Condorraptor currumili (Rauhut, 2005) in Argentina (integrating the family Piatnitzkysauridae of Carrano et al., 2012), and the presence of Afrovenator abakensis in the Middle/Late Jurassic of Niger (Sereno et al., 1994; age from Rauhut & López-Arbarello, 2009) and possible megalosaurids from the Neocomian of Argentina (Canale et al., 2017). Megalosaurids reached Pangean distribution, and lived mostly in the Middle Jurassic of Europe. Along with Lesanshaurus from China (originally described as a sinraptorid by Li et al., 2009 but retrieved as an afrovenatorine by Carrano et al., 2012) and Wiehenvenator from Germany (Rauhut et al., 2016), Torvosaurus is one of the few

genera that lived during the Late Jurassic, particularly in EE.UU. (Torvosaurus tanneri) Portugal (T. gurneyi), Germany (see above), possibly Spain (Malafaia et al., 2007 and references therein) and now also in Uruguay and Tanzania. Other possible megalosaurid material from the Tendaguru Formation which support the interpretation given herein includes a large tibia (Rauhut, 2011) and a large ulna (Malafaia et al. 2017). The latter authors favourably compared an ulna from Portugal to those of Torvosaurus, Wiehenvenator and ‘Megalosaurus’ ingens. In South America, besides two tooth-based ‘Megalosaurus’ species described by Del Corro (1966, 1974) that do not belong in Megalosauridae (Carrano et al., 2012), there are two basal Megalosauria of the family Piatnitzkysauridae: Piatnitzkysaurus and Condorraptor, both from the Middle Jurassic of Chubut, Argentina (Bonaparte, 1979; Rauhut, 2005). An interesting fact is that the third member of the family, Marshosaurus, comes from the Late Jurassic of USA (Carrano et al., 2012). The only possible megalosaurid reported from South America is based on teeth from the Neocomian of Neuquén, Argentina (Canale et al., 2017). If confirmed, it would represent the youngest megalosaurid in the world. Along with ceratosaurids with lingually grooved mesial teeth (Soto & Perea, 2008), the presence of Torvosaurus is a strong evidence of the Late Jurassic age of the fossiliferous horizon. The joint presence of ceratosaurids and Torvosaurus suggest a connection of the Tacuarembó Formation with Late Jurassic units of Tanzania (Tendaguru Formation), USA (Morrison Formation) and Portugal (Lourinhã Group of Mateus, 2006; or Praia de Amoreira-Porto Novo and Alcobaça formations of Malafaia et al., 2017), which share abundant vertebrate taxa (see review by Mateus, 2006). It is interesting to note that the relatively well-known freshwater fish assemblage from the Tacuarembó Formation (including hybodontid sharks, ginglymodians, ceratodontiform dipnoans and mawsoniid coelacanths; Perea et al., 2001; Perea et al., 2009; Soto & Perea, 2010; Soto et al., 2012) is different from that of the Tendaguru Formation, probably due to different salinities. Paleobiological implications Torvosaurus was one of the largest predators in the Late Jurassic (Hendrickx & Mateus, 2014a), only equalled or slightly surpassed by the sympatric Saurophaganax and a few Cretaceous taxa such as Tyrannosaurus, Carcharodontosaurus, Giganotosaurus and Spinosaurus (Therrien & Henderson, 2007). The gigantic size attained by Torvosaurus is reflected by the large size of their teeth. This size made it able to fed even upon sauropod dinosaurs (at least juvenile and sick individuals), so far only represented by trackways (Mesa & Perea, 2015). All the Uruguayan teeth, except FC-DPV 2971, have their tips heavily worn off, a common trait in theropod teeth as found by Chandler (1990). According to D’Amore (2009) this can be explained because is the apex which receives initial resistance from the substrate. But in the Uruguayan teeth tips are even broken and then worn off, similar to the enamel spalling described by Schubert & Ungar (2005), suggesting some kind of tooth-to-bone contact, as in tyrannosaurids. FC-DPV 2971 would have fallen from the jaws prior to tip breakage, although not after mesial carina have been worn off . In all teeth, finally, mesial carinae show consistently more wear than the distal one, as in smaller Uruguayan theropods (see Soto, 2010). D’Amore and Blumenschine (2012) found that mesial denticles in Varanus komodoensis receive more wear and for this reason tend to be stouter than distal ones. The relative abundance of megalosaurid teeth in Bidegain Quarry (scarcely represented in both Los Rosanos and Martinote) can have either a paleoenvironmental

or taphonomic explanation. The inferred paleoenvironment in Martinote, for instance, is an ephemeral river (Mesa, 2016), i.e. a highly energetic one. This is coherent with the higher abrasion, fracturing and disarticulation observed in fossil from Martinote when compared with Bidegain Quarry. Although Torvosaurus may have been abundant in Martinote, only a small tooth fragment was preserved (FC-DPV 1951). In Los Rosanos, in turn, the inferred paleoenvironment is a braided, perennial river (Mesa, 2016). There the early known, most complete bone-beds (see Soto, 2016) are no more exposed, and scarce and fragile fossils have been recovered during the last years associated to pelithic intraclasts. For this reasons, the 1 to 1.5-m thick and laterally extensive bonebed in Bidegain Quarry has yielded almost all Torvosaurus remains, and the only known complete teeth. Bakker (2000) hipothetized that megalosaurids, along with ceratosaurids, fed on aquatic and semi-aquatic preys related to swampy terrains, in contrast to allosaurids, which would prey upon sauropods and ornithischians in floodplains. Recently, Rauhut et al. (2016) proposed that allosaurids and megalosaurids would have had different environmental preferences, the former being more common in inland areas while the latter being dominant in marine and coastal environments. This can be the case of the Tanzanian Torvosaurus (interpreted as a carcharodontosaurid by Rauhut, 2011; Rauhut et al., 2016), given that the Tendaguru Formation represents a nearshore, tidal environment (Bussert et al., 2009), but not of the strictly continental Tacuarembó Formation. CONCLUSIONS It has been shown through detailed morphological analysis that several teeth from the Late Jurassic of Uruguay and Tanzania belong to the megalosaurine Torvosaurus, an identification also supported by discriminant and cluster analyses on different datasets, as well as a phylogenetic analysis, a powerful combination only paralleled by one very recent study (Hendrickx et al., in press). Finding of new materials is desirable to increase the knowledge of this Gondwanan megalosaurid. This taxon, the apex predator in the Tacuarembó Formation assemblage, strongly suggests a Late Jurassic age for the fossiliferous horizon. Moreover, it represents the first unquestionable megalosaurid from South America. ACKNOWLEDGEMENTS This paper is part of the results of the PhD dissertation of the first author (MS). We are in debt with J. S. da Silva, A. Manzuetti, and the Rodríguez cousins who collected the material described herein. V. Mesa and A. Batista provided field support. F. Cabrera skillfully renderized FC-DPV 2971. F. Agnolín kindly sent plates of the Janensch (1925) paper, and O. Rauhut and C. Hendrickx kindly authorized the reproduction of photographs of ‘Megalosaurus’ ingens teeth. Taylor and Francis authorized the reproduction of Carcharodontosaurus saharicus teeth. We are grateful to colleagues in Museo Egidio Feruglio and Museo Carmen Funes that allowed examination of Tyrannotitan and Condoraptor teeth in their collections. C. Hendrickx, an anonymous reviewer and the editor greatly contributed to improve an original draft of this manuscript. Funding: this is a contribution to project CSIC/UdelaR-2018/134 (responsible: DP). The first author dedicated this paper with love to Lucía and Leticia.

FIGURE CAPTIONS Figure 1. A, general view of Bidegain Quarry. Arrow shows the fossiliferous horizon. Inset depicts the location of Uruguay in South America. B, detail of a complete theropod tooth found in situ, perpendicular to bedding planes. Figure 2. Torvosaurus sp. FC-DPV 2971, lateral tooth in lingual (A), mesial (B), labial (C), distal (D) and basal (E) views. Scale = 1 cm. bld, basolingual depression, dc, distal carina, pc, pulp cavity. Figure 3. Torvosaurus sp. FC-DPV 2971 under binocular lens. A, detail of distal denticles. B, detail of interdenticular sulci. C, detail of braided enamel texture and transversal undulations. Scale = 2,5 mm (A) and 5 mm (B, C). is, interdenticular sulci, tu, transverse undulations. Figure 4. Torvosaurus sp. FC-DPV 2343, lateral tooth under binocular lens. A, detail of mesial view, showing the morphology of the mesial carina. B, detail of lingual view, showing enamel transverse undulations. Scale = 1 cm. mc, mesial carina, tu, transverse undulations. Figure 5. Torvosaurus sp. MGT-1184, mesial tooth in lingual (A), mesial (B), labial (C), distal (D) and basal (E) views. Scale = 1 cm. dc, distal carina, tu, transverse undulations. Figure 6. Torvosaurus sp. MGT-142, mesial tooth in lingual (A), mesial (B), labial (C), distal (D) and basal (E) views. Scale = 1 cm. dc, distal carina, is, interdenticular sulci, mc, mesial carina. Figure 7. Torvosaurus sp. Distal carina fragment FC-DPV-1951 under binocular lens, showing details of denticles, interdenticle sulci, transverse (or marginal?) undulations and enamel texture. A, part of original specimen, lacking denticles but with well-developed interdenticular sulci. B, gold-coated part of original specimen, showing coarse denticulation. Scale = 1 mm. is, interdenticular sulci, tu, transverse undulations. Figure 8. Comparison among selected large theropod teeth. A-C, Torvosaurus sp. A, FC-DPV 2971, lingual view. B, FC-DPV 2971, distal view. C, FC-DPV 1951, detail of distal denticles in labial/lingual view. D-F, Torvosaurus gurneyi. D, ML 1100 in labial view (reversed). E, ML 1100 in distal view (reversed). F, detail of distal denticles in D. G-H, Carcharodontosaurus saharicus. G, SGM Din-1 in lingual view. H, SGM Din-1 in distal view. Note conspicuous marginal undulations (wrinkles). I, J, ‘Megalosaurus’ ingens (Torvosaurus sp. according to us). I, MB R 1050 in ?lingual view. J, detail of mesial denticles of MB R 1051. D-F taken from Hendrickx & Mateus (2014a), I-J taken from Rauhut (2011) with permission of O.W.M. Rauhut, G-H taken from Brussate et al. (2007) with permission of Taylor and Francis. Scales = 1 cm (A, B, J, I), 1 mm (C), 5 cm (D, E), 3 mm (F) and 3 cm (G, H). Figure 9. BMNH R6758, cast of ‘Megalosaurus’ ingens (Torvosaurus sp. according to us) lateral tooth in lingual (A), mesial (B), labial (C), distal (D) and basal (E) views. Scale = 2 cm. Photographs courtesy of C. Hendrickx. dc, distal carina, mc, mesial carina, tu, transverse undulations.

Figure 10. Scatter plot resulting from the PCA. A, LTTD. B, personal dataset for large theropods of Young et al. (2019). Insets show variable influence. Figure 11. Dendrogram resulting from the CA (UPGMA). A, LTTD. B, personal dataset for large theropods of Young et al. (2019), in two parts. Figure 12. Dendrogram resulting from the CA (Neighbour Joining). A, LTTD. B, personal dataset for large theropods of Young et al. (2019), in two parts. Figure 13. Scatter plot resulting from the DA. A, LTTD. B, personal dataset for large theropods of Young et al. (2019). Insets show variable influence. Figure 14. Strict consensus tree of 4 MPTs from the phylogenetic analysis. Figure 15. A, paleogeographic map of the Late Jurassic, showing the main localities which have yielded megalosaurid remains in the world. 1, Tacuarembó Formation, Uruguay (Late Jurassic). 2, Tendaguru Formation, Tanzania (Late Jurassic). 3, Tiourarén Formation, Niger (Middle/Late Jurassic). 4, Morrison Formation, EE.UU. (Late Jurassic). 5, several localities, England (Middle and Late Jurassic). 6, Lourinhã Group, Portugal (Late Jurassic). 7, several localities, France and Germany (Middle and Late Jurassic). 8, Shangshaximiao Formation, China. B, geographical distribution of the Megalosauridae prior to this contribution. C, geographical distribution of the megalosauridae proposed herein. Map from Deep Time Maps.

LITERATURE CITED Abler, W.L. 1992. The serrated teeth of tyrannosaurid dinosaurs, and biting structures in other animals Paleobiology 18(2): 161-183. Azuma , Y. & Currie, P.J. 2000. A new carnosaur (Dinosauria: Theropoda) from the Lower Cretaceous of Japan. Canadian Journal of Earth Sciences 37: 1735-1753. Bakker, R.T. 2000. Brontosaur killers: Late Jurassic allosaurids as sabre-tooth cat analogues. Gaia 15: 145-158. Baszio, S. 1997. Investigations on Canadian dinosaurs: systematic palaeontology of isolated dinosaur teeth from the Latest Cretaceous of south Alberta, Canada. Courier Forschungsinstitut Senckenberg 196: 33-77. Benson, R.B.J. 2008. A redescription of ‘Megalosaurus’ hesperis (Dinosauria, Theropoda) from the Inferior Oolite (Bajocian, Middle Jurassic) of Dorset, United Kingdom. Zootaxa 1931: 57-67. Benson, R.B.J. 2010b. A description of Megalosaurus bucklandii (Dinosauria: Theropoda) from the Bathonian of the UK and the relationships of Middle Jurassic theropods. Zoological Journal of the Linnean Society 158, 882-935. Benton, M.J., Bouaziz, S., Buffetaut, E., Martill, D., Ouaja, M., Soussi, M. & Trueman, C. 2000. Dinosaurs and other fossil vertebrates from fluvial deposits in the Lower Cretaceous of southern Tunisia. Palaeogeography, Palaeoclimatology, Palaeoecology 157:227-246. Bonaparte, J.F. 1979. Dinosaurs: A Jurassic assemblage from Patagonia. Science 205: 1377-1379. Bochi, F., Scherer, C.M. dos Santos, Goso, C., dos Reis, A.D., Mesa, V. y Soto, M. 2019. Fluvial-eolian deposits of the Tacuarembo formation (Norte Basin – Uruguay): Depositional models and stratigraphic succession. Journal of South American Earth Sciences 90:355-376. Bossi, J. 1966. Geología del Uruguay. Departamento de Publicaciones de la Universidad de la República, Montevideo. 469 pp. Bossi, J., Ferrando, L.A., Fernández, A., Elizalde, G., Morales, H., Ledesma, J., Carballo, E., Medina, E., Ford, I. & Montaña, J.R. (eds.). 1975. Carta geológica del Uruguay. Escala 1/1.000.000. Montevideo. 32 pp. Britt, B.B. 1991. Theropods of Dry Mesa Quarry (Morrison Formation, Late Jurassic), Colorado, with an emphasis on Torvosaurus tanneri. Brigham Young University Geology Studies 37: 1-72. Brusatte, S.L., Benson, R.J., Carr, T.C., Williamson, T.E. & Sereno, P.C. 2007. The systematic utility of theropod enamel wrinkles. Journal of Vertebrate Paleontology 27(4):1052-1056. Buffetaut, E. 2013. An early spinosaurid dinosaur from the Late Jurassic of Tendaguru (Tanzania) and the evolution of the spinosaurid dentition. Oryctos 10, 8 pp. Bussert, R., Heinrich, W.-D. & Aberhan, M. 2009. The Tendaguru Formation (Late Jurassic to Early Cretaceous, southern Tanzania): definition, palaeenvironments, and sequence stratigraphy. Fossil Record 12:141-174. Canale, J. I., Apesteguía, S., Gallina, P.A., Gianechini, F.A. & Haluza, A. 2017. The oldest theropods from the Neuquén Basin: Predatory dinosaur diversity from the Bajada Colorada Formation (Lower Cretaceous: Berriasian–Valanginian), Neuquén, Argentina. Cretaceous Research 71:63-78. Candeiro, C.R.A. & Tanke, D.H. 2008. A pathological Late Cretaceous carcharodontosaurid tooth from Minas Gerais, Brazil. Bulletin of Geosciences 83(3): 351-354.

Canale, J.I., Scanferla, C.A., Agnolín, F.L. & Novas, F.E. 2009. New carnivorous dinosaur from the Late Cretaceous of NW Patagonia and the evolution of abelisaurid theropods. Naturwissenschaften 96(3): 409-414. Candeiro, C.R.A., Currie, P.J. & Berqvist, L. 2012. Theropod teeth from the Marília Formation (Late Maastrichtian) at the paleontological site of Peirópolis in Minas Gerais State, Brazil. Revista Brasileira de Geociencias 42(4):323-330. Carrano, M.T., Benson, R.B.J. & Sampson, S.D. 2012. The phylogeny of Tetanurae (Dinosauria: Theropoda). Journal of Systematic Palaeontology 10(2):211-300. Chandler, C.L. 1990. Taxonomic and functional significance of serrated tooth morphology in theropod dinosaurs. MSc dissertation. Department of Geology and Geophysics, Yale University, 163 pp. [unpublished] Coria, R.A. & Currie, P.J. 2006. A new carcharodontosaurid (Dinosauria, Theropoda) from the Upper Cretaceous of Argentina. Geodiversitas 28(1): 71-118. Currie, P.J. & Azuma, Y. 2006. New specimens, including a growth series, of Fukuiraptor (Dinosauria, Theropoda) from the Lower Cetaceous Kitadani Quarry of Japan. Journal of the Paleontological Society of Korea 22(1): 15-27. Currie, P.J., Rigby, J.K. (Jr.) & Sloan, R.E. 1990. Theropod teeth from the Judith River Formation of southern Alberta, Canada. Pp. 107-125 in Carpenter, K. & Currie, P.J. (eds.), Dinosaur Systematics: Perspectives and Approaches. Cambridge University Press, Cambridge. D’Amore, D.C. 2009. A functional explanation for denticulation in theropod dinosaur teeh. The Anatomical Recort 292(9). doi:10.1002/ar.20977 D’Amore, D.C. & Blumenschine, R.J. 2012. Using striated tooth marks on bone to predict body size in theropod dinosaurs: a model based on feeding observations of Varanus komodoensis, the Komodo monitor. Paleobiology 38(1):79-100. Del Corro, G. 1966. Un nuevo dinosaurio Carnivoro del Chubut (Argentina). Comunicaciones del Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Paleontol. 1:1-4. Del Corro, G. 1974. Un nuevo megalosaurio (Carnosaurio) del Cretacico de Chubut (Argentina). Comunicaciones del Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Paleontol. 1: 37-44. Fiorillo, A.R. & Currie, P.J. 1994. Theropod teeth from the Judith River Formation (Upper Cretaceous) of South-Central Montana. Journal of Vertebrate Paleontology, 14(1): 74-80. Fiorillo, A.R. & Gangloff, R.A. 2000. Theropod teeth from the Prince Creek Formation (Cretaceous) of Northern Alaska, with speculations on Arctic dinosaur paleoecology. Journal of Vertebrate Paleontology 20(4): 675-682. Fitzinger, L. 1843. Systema Reptilium. Fasciculus Primus. Amblyglossae. Apud Braumüller and Seidel Bibliopolas, Vienna 1-106. Francischini, H., Dentzien-Dias, P.C., Fernandes, M.A. & Schultz, C.L. 2015. Dinosaur Ichnofauna of the upper Jurassic/lower Cretaceous of the Paraná basin (Brazil and Uruguay). Journal of South American Earth Sciences 63:180-190. Galton, P.M. & Jensen, J.A. 1979. A new large theropod dinosaur from the Upper Jurassic of Colorado. Brigham Young University Geology Studies 26(1):1-12. Gauthier, J. A. 1986. Saurischian monophyly and the origin of birds. pp. 1-55 In Padian, K. (ed.), The Origin of Birds and the Evolution of Flight. Memoirs of the California Academy of Sciences 8. Gerke, O. & Wings, O. 2016. Multivariate and cladistics analyses of isolated teeth reveal sympatry of theropod dinosaurs in the Late Jurassic of Northern Germany. PLoS One 11(7):0158334. https://doi.org/10.1371/journal.pone.0158334

Gianechini, F.A., Makovicky, P.J, Apesteguía, S. (2011). «The teeth of the unenlagiine theropod Buitreraptor from the Cretaceous of Patagonia, Argentina, and the unusual dentition of the Gondwanan dromaeosaurids». Acta Palaeontologica Polonica 56(2):279-290. Hammer, Ø., Harper, D.A.T. & Ryan, P.D. 2001. PAST: Palaeontological Statistics software package for education and data analysis. Palaeontologia Electronica 4(1): 9 pp. Hendrickx, C., Tschopp, E. & Ezcurra, M.D. 2019. Taxonomic identification of isolated theropod teeth: the case of the shed tooth crown associated with Aerosteon (Theropoda: Megaraptora) and the dentition of Abelisauridae. Cretaceous Research. https://doi.org/10.1016/j.cretres.2019.104312 Hendrickx, C. & Mateus, O. 2014b. Torvosaurus gurneyi n. sp., the largest terrestrial predator from Europe, and a proposed terminology of the maxilla anatomy in nonavian theropods. PLoS ONE 9:e88905. Hendrickx, C. & Mateus, O. 2014a. Abelisauridae (Dinosauria: Theropoda) from the Late Jurassic of Portugal and dentition-based phylogeny as a contribution for the identification of isolated theropod teeth. Zootaxa 3759:1–74. Hendrickx, C., Mateus, O. & Araújo, R. 2015a. A proposed terminology of theropod teeth (Dinosauria, Saurischia). Journal of Vertebrate Paleontology 35(5). Hendrickx, C., Mateus, O. & Araújo, R. 2015b. The dentition of megalosaurid theropods. Acta Palaeontologica Polonica 60:627–642. Hone, D.W.E. & Rauhut, O.W.M. 2009. Feeding behaviour and bone utilization by theropod dinosaurs. Lethaia 43:232–244. Hone, D.W.E., Wang, K., Sullivan, C., Zhao, X., Chen, S., Li, D., Ji, S., Ji, Q. & Xu, X. 2011. A new, large tyrannosaurine theropod from the Upper Cretaceous of China. Cretaceous Research 32(4): 495–503. Janensch, W. 1920. Über Elaphrosaurus Bambergi und die Megalosaurier aus den Tendaguru–Schichten Deutsch–Ostafrikas. Sitzungsberichte der Gessellschaft Naturforschender Freunde zu Berlin, 225–235. Janensch, W. 1925. Die Coelurosaurier und Theropoden der Tendaguru-Schichten Deutsch-Ostafrikas.Palaeontographica Supplement 7:1–99. Li, F., Peng, G., Ye, Y. Jiang, S. & Huang, D. 2009. A new carnosaur from the Late Jurassic of Qianwei, Sichuan, China. Acta Geologica Sinica 83(9):1203–1213. Lindoso, R.M., Medeiros, M.A., Carvalho, I. de S. & Marinho, T. da S. 2012. Masiakasaurus-like theropod teeth from the Alcantara Formation, Sao Luis Basin (Cenomanian), northeastern Brazil. Cretaceous Research 36:119-124. Malafaia, E.F., Mocho, P., Escaso, F. and Ortega, F. 2017. New data on the anatomy of Torvosaurus and other remains of megalosauroid (Dinosauria, Theropoda) from the Upper Jurassic of Portugal. Journal of Iberian Geology 43(1). Marsh, O.C. 1881. Principal characters of American Jurassic dinosaurs. Part V. The American Journal of Science and Arts 3, 21(125):417-423. Mateus, O. Late Jurassic dinosaurs from the Morrison Formation (USA), the Lourinhã and Alcobaça formations (Portugal), and the Tendaguru Beds (Tanzania): a comparison. In Foster, J.R. & Lucas, S.G. (eds.), Paleontology and Geology of the Upper Morrison Formation. New Mexico Museum of Natural History and Science, Bulletin 36:223-232. Medeiros, M.A.A. 2006. Large theropod teeth from the Eocenomanian of Northeastern Brazil and the occurrence of Spinosauridae. Revista Brasileira de Paleontologia 9(3): 333-338.

Mesa, V. 2016. Caracterización litofaciológica y análisis paleoambiental del Miembro Batoví de la Formación Tacuarembó (Jurásico Tardío – Cretácico Temprano) en los alrededores de la ciudad de Tacuarembó. Trabajo Final de la Licenciatura en Geología. Facultad de Ciencias. [inédito] Mesa, V. & Perea, D. 2015. First record of theropod and ornithopod tracks and detailed description of sauropod trackways from the Tacuarembó Formation (Late Jurassic?Early Cretaceous) of Uruguay. Ichnos 22:109-121. Milner A.R.C. & Kirkland, J.I. 2007. The case for fishing dinosaurs at the St. George Dinosaur Discovery Site at Johnson Farm. Utah Geological Survey Notes 39:1–3. Novas, F. E., Salgado, L., Suárez, M., Agnolín, F. L., Ezcurra, M. N. D., Chimento, N. S. R., de la Cruz, R., Isasi, M. P., Vargas, A. O., Rubilar-Rogers, D. 2015. An enigmatic plant-eating theropod from the Late Jurassic period of Chile. Nature 522:331-334. Paul, G. S. 1988. Predatory Dinosaurs of the World. Simon and Schuster, New York. Perea, D., Soto, M., Veroslavsky, G., Martínez, S. & Ubilla, M. 2009. A Late Jurassic assemblage in Gondwana: biostratigraphy and correlations of Tacuarembó Formation, Paraná Basin, Uruguay. Journal of South AmericanEarth Sciences 28(2):168-179. Perea, D, Ubilla, M. & Rojas, A. 2003. First report of theropods from the Tacuarembó Formation (Late Jurassic-Early Cretaceous), Uruguay. Alcheringa 27(2): 79-83. Pol, D. & Gasparini, Z. 2009. Skull anatomy of Dakosaurus andiniensis (Thalattosuchia: Crocodylomorpha) and the phylogenetic position of Thalattosuchia. Journal of Systematic Paleontology 7(2):163-197. Rauhut, O.W.M. 2004. Provenance and anatomy of Genyodectes serus, a large toothed ceratosaur (Dinosauria, Theropoda) from Patagonia. Journal of Vertebrate Paleontology 24(4): 894-902. Rauhut, O.W.M. 2005. Osteology and relationships of a new theropod dinosaur from the Middle Jurassic of Patagonia. Palaeontology.48(1):87-110. Rauhut, O.W.M. 2011. Theropod dinosaurs from the Late Jurassic of Tendaguru (Tanzania). Special Papers in Palaeontology 86:195-239. Rauhut, O.W.M. & Carrano, M.T. 2016. The theropod dinosaur Elaphrosaurus bambergi Janensch, 1920, from the Late Jurassic of Tendaguru, Tanzania. Zoological Journal of the Linnean Society. Rauhut, O.W.M., Hübner, T. R. & Lanser, K.-P. 2016. A new megalosaurid theropod dinosaur from the late Middle Jurassic (Callovian) of north-western Germany: Implications for theropod evolution and faunal turnover in the Jurassic. Palaeontologia Electronica 19.2.26A:1-65. Rauhut, O.W.M. & López-Arbarello, A. 2009. Considerations on the age of the Tiouarén Formation (Iullemmeden Basin, Niger, Africa): Implications for Gondwanan Mesozoic terrestrial vertebrate faunas. Palaeogeography, Palaeoclimatology, Palaeoecology 271:259-267. Rauhut, O.W.M. & Pol, D. 2017. A theropod dinosaur from the Late Jurassic Cañadón Calcáreo of Central Patagonia, and the evolution of the theropod tarsus. Ameghiniana 54(5):539-566. Rauhut, O.W.M. & Werner, C. 1995. First record of the family Dromaeosauridae (Dinosauria: Theropoda) in the Cretaceous of Gondwana (Wadi Milk Formation, northern Sudan). Paläontologische Zeitschrift 69(3/4): 475-486. Rauhut, O.W.M. & Kriwet, J. 1994. Teeth of a big theropod dinosaur from Porto das Barcas (Portugal). Berliner Geowissenschaftliche Abhandlungen, E, 13: 179-185.

Rich, T.H., Vickers-Rich, P., Giménez, O., Cúneo, R., Puerta, P. & Vacca, P. 1999. A new sauropod dinosaur from Chubut Province, Argentina. Pp. 61-84 in Tomida, Y., Rich, T. & Vickers-Rich, P. (eds.), Proceedings of the Second Gondwanan Dinosaur Symposium. National Science Museum Monographs 15. Rubilar-Rogers, D., Otero, R.A., Yuri-Yáñez, R.E., Vargas, A.O. & Gutstein, C.S. 2012. An overview of the dinosaur fossil record from Chile. Journal of South American Earth Sciences 37:242-255. Salgado, L., Cruz, R.D., Suárez, M., Fernández, M.S., de Gasparini, Z.B., Palma-Heldt, S. & Fanning, C.M. First Late Jurassic dinosaur bones from Chile. Journal of Vertebrate Paleontology 28(2):529-534. Sankey, J.T. 2001. Late Campanian southern dinosaurs, Aguja Formation, Big Bend, Texas. Journal of Paleontology 75(1): 208-215. Sankey, J.T., Brinkman, D.B., Guenther, M. & Currie, P.J. 2002. Small theropod and bird teeth from the Late Cretaceous (Late Campanian) Judith River Group, Alberta. Journal of Paleontology 76(4): 751-763. Schubert, B.W. & Ungar, P.S. 2005. Wear facets and enamel spalling in tyrannosaurid dinosaurs. Acta Palaeontologica Polonica 50(1): 93-99. Sereno, P.C., Dutheil, D.B., Iarochene, M., Larsson, H.C.E., Lyon, G.H., Magwene, P. M., Sidor, C.A., Varricchio, D.J. & Wilson, J.A. 1996. Predatory dinosaurs from the Sahara and Late Cretaceous faunal differentiation. Science 272: 986-991. Sereno, P.C., Wilson, J.A., Larsson, H.C.E., Dutheil, D.B. & Sues, H-D. 1994. Early Cretaceous dinosaurs from the Sahara. Science 266:267-270. Serrano-Martínez, A., Ortega, F., Sciscio, L., Tent-Manclús, J.E., Fierro Bandera, I. & Knoll F. 2015. New theropod remains from the Tiourarén Formation (?Middle Jurassic, Niger) and their bearing on the dental evolution in basal tetanurans. Proceedings of the Geologists' Association 126(1):107–18. Serrano-Martínez, A., Vidal, A., Sciscio, L., Ortega, F. & Knoll, F. 2016. Isolated theropod teeth from the Middle Jurassic of Niger and the early dental evolution of Spinosauridae. Acta Palaeontologica Polonica 61(2):403-415. Shen, Y.B., Gallego, O.F. & Martínez, S. 2004. The conchostracan subgenus Orthestheria (Migransia) from the Tacuarembó Formation (Late Jurassic-?Early Jurassic, Uruguay) with notes on its geological age. Journal of South American Earth Sciences 16: 631-638. Smith, J.B. 2005. Heterodonty in Tyrannosaurus rex: implications for the taxonomic and systematic utility of theropod dentitions. Journal of Vertebrate Paleontology 25: 865-887. Smith, J.B., Vann, D.R. & Dodson, P. 2005. Dental morphology and variation in theropod dinosaurs: Implications for the taxonomic identification of isolated teeth. The Anatomical Record Part A 285: 699–736. Soto, M. 2010. Estudio de los dientes de terópodos (Dinosauria, Saurischia) de la Formación Tacuarembó, Jurásico Tardío-Cretácico Temprano (Uruguay). Tesis de Maestría en Ciencias Biológicas, PEDECIBA, 275 pp. [unpublished] Soto, M. 2016. Fósiles de cuerpo de vertebrados de la Formación Tacuarembó (Jurásico Tardío-Cretácico Temprano), Uruguay: implicancias bioestratigráficas, biogeográficas y y paleoambientales. PhD dissertation, PEDECIBA. 436 pp. + anexos [unpublished]. Soto, M. & Perea, D. 2008. A ceratosaurid (Dinosauria, Theropoda) from the Late Jurassic-Early Cretaceous of Uruguay. Journal of Vertebrate Paleontology 28(2):439-444.

Soto, M. & Perea, D. 2010. Late Jurassic lungfishes (Dipnoi) from Uruguay, with comments on the systematics of Gondwanan ceratodontiforms. Journal of Vertebrate Paleontology 30(4):1049-1058. Soto, M., Carvalho, M.S.S., Maisey, J.G., Perea, D. & Da Silva, J. 2012. Coelacanth remains from the Late Jurassic–?earliest Cretaceous of Uruguay: the southernmost occurrence of the Mawsoniidae. Journal of Vertebrate Paleontology 32(3):530–537. Sues, H.D., Frey, E., Martill, D.M. & Scott, D.M. 2002. Irritator challengeri, a spinosaurid (Dinosauria: Theropoda) from the Lower Cretaceous of Brazil. Journal of Vertebrate Paleontology 22(3):535-547. Tavares, S.A., Branco, F.R. & Santucci, R.M. 2014. Theropod teeth from the Adamantina Formation (Bauru Group, Upper Cretaceous), Monte Alto, Sao Paulo, Brazil. Cretaceous Research 50:59-71. Therrien, F. & Henderson, D.M. 2007. My theropod is bigger than yours... or not: estimating body size from skull lenght in theropods. Journal of Vertebrate Paleontology 27(1): 108-115. Toriño, P., Soto, M. & Perea, D. 2018. Three-dimensional reconstruction of the head of the coelacanth Mawsonia (Actinistia, Latimerioidei), using CT-scanning. VI Congreso Latinoamericano de Paleontología de Vertebrados, Villa de Leyva, 20 al 25 de agosto de 2018, pp. 88-89. Van der Lubbe, T., Richter, U. & Knötschke, N. 2009. Velociraptorine dromaeosaurid teeth from the Kimmeridgian (Late Jurassic) of Germany. Acta Paleontologica Polonica 54(3): 401-408. Walker, A. D. 1964. Triassic reptiles from the Elgin area: Ornithosuchus and the origin of carnosaurs. Philosophical Transactions of the Royal Society B. 248 (744): 53– 134. Young, C.M.E., Hendrickx, C., Challands, T.J., Foffa, D., Ross, D.A., Butler, I.B. & Brusatte, S.L. 2019. New theropod dinosaur teeth from the Middle Jurassic of the Isle of Skye, Scotland. Scottish Journal of Geology 55:7-19.

Catalogue number FC-DPV-2971 FC-DPV-2972 MGT-1139 MGT-142 MGT-1184 FC-DPV-2343 FUB PB Ther 1 MB R 1050 BMNH R 6758

Provenance Late Jurassic, Uruguay Late Jurassic, Uruguay Late Jurassic, Uruguay Late Jurassic, Uruguay Late Jurassic, Uruguay Late Jurassic, Uruguay Late Jurassic, Portugal Late Jurassic, Tanzania Late Jurassic, Tanzania

CH 77,00 68,00* 73,19* >30,43 >35,0 ? 81,70 118,90 130,96*

CBW 15,00 14,40 18,75 11,06 14,00 14,40* 17,19 23,00 27,88

CBL 33,00 29,00* 34,58 15,63 19,40 28,50* 32,67 48,00 53,96

AL 86,70 74,00* 80,55* >32,45 >39,0 ? 88,30 128,90 134,97

DC 7,0 6,0 5,0 8,0 8,0 ? 6,5 5,5 5,5

Table 1. Selected theropod shed teeth from the Late Jurassic or earliest Cretaceous. Measurements of non-Uruguayan material taken or measured from illustrations in Janensch (1925), Rauhut & Kriwet (1994), Rauhut (2011) and C. Hendrickx (pers. com., 2019). Measurements in mm, except for DC. *estimated measurement.

Family

General shape

Distal profile

CH> 80 mm

DC <7

Mesial carinae

Enamel texture

Marginal ondulations (wrinkles)

Interdenticular sulci

Ceratosauridae

Ziphodont

Concave

Yes

No

Developed, mid-line

Braided

Present

?

Abelisauridae

Ziphodont, often brachydont

Straight or slightly convex

No

No

Developed, mid-line

Irregular

Present5

Present

Megalosauridae

Ziphodont

Concave

Yes

Yes2

Restricted or developed, mid-line

Braide d

Present 6

Present

Carcharodontosauridae

Ziphodont

Straight or concave

Yes

No

Developed, mid-line4

Braided

Present7

Present

Present

Present

Present

Present

Present in some teeth8

Present

Allosauridae

Ziphodont

Concave

No

No

Tyrannosauridae

Pachydont

Concave

Yes

Yes, rare3

Uruguayan and Tanzanian material

Ziphodont

Concave Yes1

Yes

Developed, often twisted Developed, often twisted Developed, mid-line

Irregular or braided Irregular or braided Braided

Table 3. Comparison of selected features (lateral teeth only) of the Uruguayan material and other large theropod taxa. Based on Soto (2010) and references therein, Hendrickx & Mateus (2014) and Hendrickx et al. (2015b). 1If FC-DPV 1139 was complete it would attain at least 80 mm, as also indicate large tooth fragments from Cantera Bidegain. 2Particularly in Torvosaurus. 3 Present in some Tyrannosaurus teeth. 4Twisted lingually in Acrocanthosaurus. 5In Skorpiovenator. 6In Megalosaurus and Torvosaurus. 7Arcuate in Carcharodontosaurus. 8 Particularly from Tanzania, the only Uruguayan exception being possibly FC-DPV 1951.

Taxon

CH

Magnosaurus

-

Afrovenator

61,1 14,127,7 29,351,7

CBR

CHLR

CHWR

DC

0,610,74 0,42 0,360,73 0,380,63

-

-

2,21 1,422,22 1,612,36

5,22 2,865,53

13-63,9

0,390,77

1,772,54

3,414,29

7-14,5

Wiehenvenator

43,5117 42-73

0,360,62 -

1,752,8 -

3,176,49 -

5,59,5 7-8

Uruguayan material

30,4377

0,450,71

1,742,34

2,755,13

5-8,5

Dubreuillosaurus Duriavenator Megalosaurus Torvosaurus

3,3-4,92

11,514 8-10 11,516 7,512,5

Marginal Transverse undulations undulations (wrinkles)

Interdenticular sulci

Absent

Absent

Present

Absent

Present

Present

Absent

Absent

Present

Present, tenuous

Absent

Present

Present, well visible Present, well visible ? Present, tenuous or well visible

Present Present ? Absent*

Present, sometimes well developed Present, well developed ? Present, well developed

Table 4. Comparison of selected measurements and ratios of the Uruguayan material with megalosaurid taxa. Magnosaurus, Afrovenator and Dubreuillosaurus are afrovenatorines, the remaining taxa are megalosaurines (Carrano et al., 2012). Based on Hendrickx et al. (2015b) and Rauhut et al. (2016). *Except possibly in FC-DPV 1951.

Catalogue number FC-DPV-2971 FC-DPV-2972 MGT-1139 FUB PB Ther 1 MB R 1050 BMNH R6758

DA 1 DA 2 Hit ratio 64.31% Hit ratio 60.80% Torvosaurus Basal Ceratosauria Torvosaurus Basal Ceratosauria Torvosaurus Torvosaurus Torvosaurus Torvosaurus Torvosaurus Dilophosaurus Carcharodontosaurinae

Table 5. Results of the discriminant analysis for isolated teeth (see Table 1).

• • • •

We describe a large theropod from Uruguay represented by isolated teeth Detailed morphological analysis strongly resembles the megalosaurine Torvosaurus Multivariate and phylogenetic analyses support this referral We propose that the enigmatic ‘Megalosaurus’ ingens from Tanzania should also be referred to Torvosaurus

Matías Soto. Conceptualization; Data curation; Formal analysis; Investigation; Methodology; Software; Supervision; Validation; Visualization; Roles/Writing – original draft; Writing – review & editing. Pablo Toriño. Formal analysis; Investigation; Methodology; Validation; Roles/Writing – original draft; Writing – review & editing. Daniel Perea. Formal analysis; Funding acquisition; Investigation; Project administration; Supervision; Roles/Writing – original draft; Writing – review & editing.

The authors declare they have no conflicts of interest.

Matías Soto Pablo Toriño Daniel Perea