A dinosaur ilium from the Late Triassic of Brazil with comments on key-character supporting Saturnaliinae.

Discoveries in Carnian-aged rocks are establishing a rich and diverse dinosaurian fauna at the so-called 'dawn of the age of dinosaurs' in the Late Triassic of Western Gondwana. Accordingly, Brazilian strata from the Candelária Sequence have contributed extensively to this trend. Here, we present a new dinosaurian specimen (CAPPA/UFSM 0200) from this geological unit. The material was collected at a fossiliferous site that had no previous record of dinosaurs. Our specimen comprises a single ilium, which we describe in detail. Its anatomy is consistent with Carnian sauropodomorph dinosaurs, but differs from coeval specimens by several features, although we do not discard the possibility of these features being the result of intraspecific variation. In part of our phylogenetic investigation, CAPPA/UFSM 0200 was recovered within Saturnaliinae, a group comprised of Carnian sauropodomorphs from South America. However, based on examination of better-sampled coeval taxa, a character (a strong rugosity in the ilium) supporting this less inclusive position might be related to intraspecific variation and so, should be carefully considered. This study increases the distribution of dinosaur remains in fossiliferous units from southern Brazil and adds to the discussion regarding intraspecific variation and its implications in the phylogeny of early dinosaurs.


INTRODUCTION
Upper triassic units from southern Brazil include the oldest dinosaur-bearing sites worldwide, dating back to the Carnian Stage 237-227 Ma . Over the last few years, outcrops from the Candelária Sequence (sensu horn et al. 2014), have provided several exceptional dinosauromorph specimens (e.g. Cabreira et al. 2011, 2016, Müller et al. 2018a, Pretto et al. 2018) from the Hyperodapedon Assemblage Zone (AZ) . Consequently, it is of paleontological interest to further recognize and identify dinosaurian specimens from the localities of this unit, because they hold fundamental data regarding the early evolution and radiation of dinosaurs. So far, the dinosaurian fauna from the Hyperodapedon AZ of the Candelária Sequence is mostly represented by herrerasaurids (Colbert 1970) and early-diverging sauropodomorphs (Langer et al. 1999, Cabreira et al. 2011, 2016, Müller et al. 2018a, Pretto et al. 2018, in which pelvic girdle/hindlimb remains are frequently sampled (e.g. Pretto et al. 2015, Müller et al. 2014, 2017a. Pelvic elements provide important diagnostic information for these clades (Novas 1996, Sereno 1999, and the identification and comparative description of these bones is fundamental for a comprehensive knowledge on early dinosaurian evolution and diversification. Comprised of pairs of ilia, pubes and ischia, the unique pelvic morphology of dinosaurs and other dinosauromorphs allowed bipedal posture and cursorial locomotion, resulting in a highly specialized anatomical structure when compared to that of other archosaurs (e.g. Nesbitt 2011, Ezcurra 2016. the ilium is well-sampled in most early dinosaurs and dinosaurian relatives (e.g. Dzik 2003, Langer 2003, Cabreira et al. 2016, which makes it an important source of morphological data in these clades (Langer et al. 2010), even providing key characters that support some groups (Ezcurra 2010. Particularly, the observation of a set of traits (especially rugosities related to muscle attachments) present in early dinosaurs and their close relatives raises a series of questions: are these rugosities dependent on intraspecific variation? If so, could they represent an ontogenetic feature? Are these traits reliable as phylogenetic characters (i.e. synapomorphic features), as previously suggested? Do they carry phylogenetic signal at all? Are they present in the same extent in other dinosauriforms? In an effort to assess some of these questions we describe here a partial left ilium that comprises the first dinosaurian specimen from the Piche site (Late triassic of southern Brazil), in the municipality of São João do Polêsine, State of rio Grande do Sul, Brazil. Additionally, we provide a comparative assessment of the iliac morphology among early dinosaurs and their kin.
Institutional abbreviations -BMNH, British Museum Natural history, London, UK; CAPPA/ UFSM, Centro 1980). Besides CAPPA/UFSM 0200, this site has also yielded conchostracans (Jenisch et al. 2017), hybodontiformes (Perez and Malabarba 2002), actinopterygians (Perez and Malabarba, 2002), aetosaurs and hyperodapedontyn rhynchosaurs . the fossil record of this site is compatible with those from the Hyperodapedon Assemblage Zone, in which the upper level of its type-locality was radioisotopically dated as 233.23 ± 0.73 Ma . therefore, the fauna of the Piche outcrop is considered Carnian in age.

DESCrIPtION
Most specimens from Argentina and Brazil were examined first-hand and listed in table I. the overall morphology of CAPPA/UFSM 0200 resembles that of basalmost saurischian dinosaurs (e.g. Langer 2003, Cabreira et al. 2016, Müller et al. 2018a, with the exception of herrerasaurids (Colbert 1970, Novas 1994. the acetabulum of CAPPA/UFSM 0200 is not fully perforated and the specimen presents a well-developed postacetabular ala (Fig. 2), as in several other basal saurischians (Langer 2003, Ezcurra 2010, Cabreira et al. 2016, differing from herrerasaurids (Colbert 1970, Novas 1994. the iliac blade is dorsoventrally tall, as in most dinosaurs, and the preserved dorsal margin bears rugosities (possibly related to muscle attachment) which are further described below. A deep concavity is situated on the lateral surface of the cranial portion of the iliac blade, which possibly corresponds to the attachment area of m. iliofemoralis (see hutchinson 2001hutchinson , Langer 2003. According to these authors, this morphology represents a plesiomorphic trait among dinosaurs, as it is also observed in Marasuchus lilloensis, Herrerasaurus ischigualastensis ( Fig. 3k), Caseosaurus crosbyensis, and Thecodontosaurus antiquus. however, in CAPPA/UFSM 0200 this concavity is substantially deeper than that observed in coeval taxa (e.g. Buriolestes schultzi, Pampadromaeus barberenai, Saturnalia tupiniquim). In lateral view, the dorsal margin of the preserved portion of the iliac blade is almost straight, as in Buriolestes schultzi (ULBrA-PVt280) and Chromogisaurus novasi, slightly contrasting with the mostly convex shape present in Saturnalia tupiniquim (Fig. 2, 3). C A P PA / U F S M 0 2 0 0 p o s s e s s e s a postacetabular ala that is more prominent than its preacetabular counterpart, a condition shared with several other coeval saurischian dinosaurs, such as Buriolestes schultzi, Saturnalia tupiniquim, Staurikosaurus pricei, and non-dinosaurian dinosauromorphs such as Marasuchus lilloensis, silesaurids, and herrerasaurids (Fig. 2, 3). Both alae possess conspicuous and strong developed rugosities (see below). Although the pubic peduncle of CAPPA/UFSM 0200 is fragmented, the cranial margin of its preacetabular ala probably did not reach the cranialmost extent of the pubic peduncle, a feature that also occurs in sauropodomorphs as Buriolestes schultzi and Efraasia minor, and the herrerasaurids Herrerasaurus ischigualastensis and Staurikosaurus pricei (Fig. 2, 3).

An Acad Bras Cienc
the postacetabular ala of CAPPA/UFSM 0200 is slightly more robust than that of coeval basal saurischian dinosaurs (e.g. Buriolestes schultzi, Panphagia protos) excepting herrerasaurids, resembling the condition present in Chromogisaurus novasi, Guaibasaurus candelariensis, and Nhandumirim waldsangae. As in most basal forms, such as Bagualosaurus agudoensis, Buriolestes schultzi, Guaibasaurus candelariensis, Panphagia protos, Saturnalia tupiniquim, and also in nondinosaurian dinosauriforms (Peecook et al. 2013), the postacetabular ala of CAPPA/UFSM 0200 is caudally elongated, possesses a well-developed brevis shelf which laterodorsally delimits an also well-developed brevis fossa, both acting as attachment areas for the m. caudofemoralis brevis (Gatesy 1990(Gatesy , hutchinson 2001 (Fig. 2a, 2c). In CAPPA/UFSM 0200 the brevis fossa is more ventrally located than in Bagualosaurus agudoensis, Buriolestes schultzi, Chromogisaurus novasi, and Silesaurus opolensis. As in Buriolestes schultzi and Pampadromaeus barberenai, the shelf itself does not merge cranially with the supraacetabular crest. Caudal to the supraacetabular crest, and dorsal to the ischiadic peduncle, CAPPA/UFSM 0200 bears a small foramen (Fig. 2a, 2c), which we tentatively relate to the innervation of the m. caudofemoralis brevis. this foramen is similar to that present in Buriolestes schultzi (ULBrA-PVt280) (Fig. 2a,  2c), Efraasia minor, Nhandumirim waldsangae (which presents two foramina instead of one), and Pampadromaeus barberenai. At the caudalmost portion of the postacetabular ala, CAPPA/UFSM 0200 presents a strong developed rugosity on the lateral side of the ilium (Fig. 2, 3a) that forms a raised surface or protuberance, which is more prominent than that of Asilisaurus kongwe, Caseosaurus crosbyensis, Eoraptor lunensis, Herrerasaurus ischigualastensis, Ignotosaurus fragilis, Lutungutali sitwensis, Silesaurus opolensis, and even Buriolestes schultzi, Chromogisaurus novasi, and Saturnalia tupiniquim (see Discussion) (Fig. 3). the cranial margin of this rough rugosity connects to the extended rugosity area on the dorsal margin of the iliac blade and possibly relates to the attachment for either m. flexor tibialis externus or m. iliofibularis (Langer 2003, Ezcurra 2010. the medial blade of the postacetabular ala, which extends craniocaudally, is ventromedially developed, forming roughly a right angle with the brevis shelf. the supraacetabular crest of CAPPA/UFSM 0200 is fragmented on its cranialmost portion, where the pubic peduncle would be located (Fig.  2a, 2c). As in Buriolestes schultzi, Chromogisaurus novasi, and Panphagia protos the supracetabular crest extends lateroventrally, forming the acetabular roof, and its lateralmost extension is located slightly caudal to the ischiadic peduncle. In CAPPA/UFSM 0200, the supraacetabular crest extends ventrolaterally, forming an angle of 65° relative to the acetabular wall and partially covering the acetabulum. this character state is present in neotheropods, such as Coelophysis, Dilophosaurus, Liliensternus, Ceratosaurus, and Eoabelisaurus (Langer et al. 2017). however, in CAPPA/UFSM 0200 it is difficult to determine if this is either a taphonomic artifact (Müller et al. 2018b) or a unique trait among coeval taxa, because the bone surface is crushed right above the supraacetabular crest. the acetabulum is roughly as lateromedially deep as craniocaudally long, differing from Nhandumirim waldsangae, and the acetabular wall is lateromedially compressed on its cranial portion. Additionally, its preserved ventral margin is mostly straight, but with a faint concavity, approaching the condition observed in Chromogisaurus novasi and Pampadromaeus barberenai, and contrasting with Bagualosaurus agudoensis, Buriolestes schultzi, and Saturnalia tupiniquim, as these possess an almost straight ventral margin, although these differences may be due to taphonomic and preservational processes (Müller et al. 2018b). As in most basal saurischian dinosaurs, the ischiadic peduncle extends ventrocaudally, and its articular surface is ovoid in cross section, the convex cranioventral surface, which corresponds to the antitrochanter , merges cranially with the acetabulum wall. In addition, the antitrochanter of CAPPA/UFSM 0200 does not present a raised process (Fig. 2), as in Guaibasaurus candelariensis and Ixalerpeton polesinensis. In the homologous area of the antitrochanter of CAPPA/UFSM 0200, however it is indeed possible to observe a slight variation on the texture of the bone surface as in Guaibasaurus candelariensis .

RESULTS
In the first analysis using the dataset of Cabreira et al. (2016) (Fig. 4a), we recovered 432 MPts of 846 steps each [CI (consistency index) = 0.348, rI (retention index) = 0.637, rC (rescaled consistency index) = 0.221], and the strict consensus tree places CAPPA/UFSM 0200 in a polytomy within saurischian dinosaurs, as neither a sauropodomorph nor a theropod. the second analysis employing this dataset (Fig. 4b), which included character 257, recovered 54 MPts of 848 steps (CI = 0.348, rI = 0.638, rC = 0.222), and CAPPA/UFSM 0200 was nested as a saturnaliin sauropodomorph in all trees. the strict consensus tree recovered CAPPA/ UFSM 0200 in a sister group relationship with Saturnalia tupiniquim, with Chromogisaurus novasi recovered as the sister taxon to this clade. As defined by Ezcurra (2010), Saturnaliinae includes Chromogisaurus novasi, Saturnalia tupiniquim, their last common ancestor and all its descendants. the only character supporting the clade CAPPA/UFSM 0200 + Saturnalia tupiniquim is the iliac blade depth relative to the acetabulum being twice deeper or more [249 (1)]. Among the synapomorphies that support Saturnaliinae in this analysis, CAPPA/UFSM 0200 only presents a strong trapezoidal rugosity that extends over the caudal portion of the postacetabular process [257 (1)]. It is important to point out that this last character is the one included in the second analysis using this dataset. the analysis with the dataset of   (Fig. 4c)  Finally, in the analysis employing the dataset of Langer et al. (2017) (Fig. 4d), we recovered 443520 MPts of 1927 steps each (CI = 0.273, rI = 0.619, rC = 0.168). CAPPA/UFSM 0200 nests within Saturnaliinae in all trees in an unresolved arrangement, which also includes Buriolestes schultzi, Chromogisaurus novasi, Pampadromaeus barberenai, Saturnalia tupiniquim, and Panphagia protos. Curiously, Eoraptor lunensis was recovered outside this clade. Among the 10 synapomorphies supporting Saturnaliinae, only two are scored for CAPPA/UFSM 0200: straight ventral margin of the acetabular wall of the ilium [306 (1)], and presence of rugosity areas on the dorsal and lateral surfaces of the preacetabular and the postacetabular processes of the ilium [318 (1)].

DISCUSSION
the discovery of CAPPA/UFSM 0200 increases the record of Carnian dinosauromorphs in southern Brazil, comprising the first dinosaur collected at Piche outcrop, quantitatively improving the distribution of dinosaurian remains within the Hyperodapedon Assemblage Zone of the Candelária Sequence. Outcrops of this fossiliferous unit and their correlates in the Ischigualasto Formation (northwestern Argentina) include a dinosauromorph fauna that, so far, comprises lagerpetids (Sereno and Arcucci 1994, Cabreira et al. 2016, silesaurids , see also Agnolin and rozadilla 2017, Baron 2017), putative ornithischians (Casamiquela 1967, but see Agnolin and rozadilla 2017, Baron 2017), putative theropods (Martínez et al. 2011, Marsola et al. 2019, and other saurischians, especially herrerasaurids (reig 1963, Colbert 1970, Alcober and Martínez 2010 and sauropodomorphs (Eoraptor lunensis Sereno et al. 1993, Saturnalia tupiniquim Langer et al. 1999, Panphagia protos Martínez and Alcober 2009, Chromogisaurus novasi Ezcurra 2010, Pampadromaeus barberenai Cabreira et al. 2011, Buriolestes schultzi Cabreira et al. 2016, Müller et al. 2018a, Bagualosaurus agudoensis Pretto et al. 2018. Beyond that, CAPPA/UFSM 0200 possesses the usual traits of Carnian saurischian dinosaurs (e.g. postacetabular ala more developed than the preacetabular ala; elongated postacetabular ala; partially perforated acetabulum) and it is mostly similar to early-diverging sauropodomorphs as Buriolestes schultzi, Chromogisaurus novasi, and Saturnalia tupiniquim. In fact, CAPPA/UFSM 0200 is consistently recovered as a saurischian dinosaur in the phylogenetic analyses herein presented and as a saturnaliin sauropodomorph in some of the analyses (Fig. 4). Although CAPPA/UFSM 0200 is morphologically different from Saturnalia tupiniquim, they share the same character states for the ilium in all datasets. Nonetheless, it is relevant to mention that CAPPA/UFSM 0200 is not complete and lacks 40% of the character states for the ilium. Moreover, the morphology of CAPPA/UFSM 0200 also differs from other coeval taxa mainly by the following combination of traits: concavity on the iliac blade, which is lateromedially deeper than in coeval sauropodomorphs; preacetabular ala that is shorter than in coeval sauropodomorphs; presence of strong developed rugosities on the pre-and postacetabular alae. Individually, similar traits occur in several saurischian dinosaurs (especially in early sauropodomorphs), but in CAPPA/UFSM 0200 their combination is unique. For instance, while Buriolestes schultzi also has a short preacetabular ala relatively to other Carnian sauropodomorphs (e.g. Pampadromaeus barberenai; Saturnalia tupiniquim), CAPPA/ UFSM 0200 has a shorter preacetabular ala than Buriolestes schultzi. Another example relies in the lateral concavity, which is lateromedially deeper in Chromogisaurus novasi and Saturnalia tupiniquim, but in CAPPA/UFSM 0200 is even deeper than in those taxa. Consequently, CAPPA/UFSM 0200 may either belong to a new, still unknown taxon from the Candelária Sequence or to an ontogenetically advanced individual belonging to a previously known taxon (see further discussion below), because the aforementioned traits are under the acceptable range of individual variation (i.e. ontogeny, sexual dimorphism).
One of the most conspicuous traits of the specimen relies on the strongly developed rugosities in its pre-and postacetabular alae, extending to the iliac blade, and these may be an artifact of ontogeny (see further discussion below). Although some coeval dinosauriforms do show similar rugosities (Langer 2003, Ezcurra 2010, Cabreira et al. 2016, Müller et al. 2018a, they are fainter than in CAPPA/UFSM 0200. It is important to point out that different specimens of Buriolestes schultzi present variable conditions regarding this trait (Fig. 5), though neither of the specimens reach the robustness of CAPPA/UFSM 0200. the holotype of Buriolestes schultzi (ULBrAPVt280) and a referred specimen (CAPPA/UFSM 0035) both possess rugosities on these areas, whereas ULBrA-PVt056 (a putative juvenile individual) does not present the same condition. to a certain extent, such variation is also observed in distinct specimens of Saturnalia tupiniquim, while MCP 3944-PV and MCP 3945-PV present conspicuous rugosities, MCP 3846-PV does not present the same condition.
A similar condition regarding the iliac rugosities is observed in silesaurids and herrerasaurids such as Asilisaurus kongwe, Caseosaurus crosbyensis, Herrerasaurus ischigualastensis, Ignotosaurus fragilis, Lutungutali sitwensis, and Silesaurus opolensis, although with slight differences regarding sauropodomorphs as Buriolestes schultzi, Chromogisaurus novasi, and Saturnalia tupiniquim. In silesaurids, sauropodomorphs and Caseosaurus crosbyensis the rugosities appear to be as not extensive as in Herrerasaurus ischigualastensis, in which these rugosities provide a "bulbous" aspect to the ilium in lateral view, although this might be a taphonomic artifact. Baron and Williams (2018) also mention the occurrence of rugosities in the ilia of Coelophysis bauri and Staurikosaurus pricei. Although, the homology of these rugosities is difficult to determine in dinosauromorphs (Baron and Williams 2018), at least in sauropodomorphs they seem to be restricted to the early-diverging forms, because Bagualosaurus agudoensis, Efraasia minor, Melanorosaurus, Pantydraco caducus, Plateosaurus, Riojasaurus incertus, Thecodontosaurus antiquus and other post-Carnian sauropodomorphs (McPhee and Choiniere 2016) seem to not present them, or to only present faint scars in the homologous area. Nonetheless, we could not observe either condition in Panphagia protos because the dorsal portion (most of the iliac blade) of the holotype's ilium is fragmented, whereas the preserved portion of the ilium (roughly the cranialmost half) of Pampadromaeus barberenai does not exhibit the rugosities on its preacetabular ala, and neither does Eoraptor lunensis. Moreover, since the strong developed rugosity is regarded as one of the key characters supporting Saturnaliinae (Ezcurra 2010, it is essential to consider if this is in fact a reliable taxonomic character or whether it may be result of intraspecific variation (e.g. ontogeny, sexual dimorphism, and individual variation). Actually, several studies demonstrated that variation play a significant role in the presence, absence, and morphology of several traits extensively applied in phylogenetic studies of dinosauromorphs (Nesbitt et al. 2009, Piechowski et al. 2014, Griffin and Nesbitt 2016a, b, Müller et al. 2017a. While an extensive analysis on the ontogeny of sauropodomorphs is beyond the scope of this paper, we list and describe some possible ontogenetic trends that are observable in specimens of Buriolestes schultzi and Saturnalia tupiniquim, including CAPPA/UFSM 0200 as a potential model for an ontogenetically advanced individual of both taxa. Following our hypothetical orientation of relative maturity in Figure 5, there is a trend though ontogeny in both the ilium of Buriolestes schultzi and Saturnalia tupiniquim of a shortening of the preacetabular ala (i.e. it becomes more rounded and/or subquadrangular and less pointed) and of the development of strong rugosities in the muscle scars present in both alae. this may be an indication that these muscle scars could reveal the relative maturity of the specimens, however without histological analyses and a broader ontogenetic approach, such assumption still remains ambiguous. regarding Saturnalia tupiniquim, it is also noticeable that the lateral concavity of the ilium becomes deeper as the specimens are more ontogenetic advanced. In this case, the size of the specimens does not directly reflect the relative maturity, once all three (MCP 3946-PV; MCP 3945-PV; CAPPA/UFSM 0200) are similar in size, although they present different conditions in the traits previously cited. On the other hand, Buriolestes schultzi preserves a more complete ontogenetic series, presenting a putative juvenile specimen (ULBrA-PVt056; see also Müller and Garcia 2019), which will be formally described elsewhere. As in MCP 3946-PV, which is herein used as the less mature specimen of Saturnalia tupiniquim, and Pantydraco caducus, ULBrA-PVt056 has a pointed preacetabular ala. Its muscle scars are faint striations along both alae, and overall it is proportionally more elongated than ULBrA-PVt280, CAPPA/UFSM 0035 and CAPPA/UFSM 0200.
Because ontogenetic data of most triassic dinosauromorphs are scarce, and many taxa are restricted to a single incomplete specimen (e.g. Colbert 1970, Martínez and Alcober 2009, Ezcurra 2010, Pretto et al. 2018, Marsola et al. 2019 the limited sample precludes the establishment of a reliable pattern to be followed as a model, whether regarding either ontogeny or individual variation. Once such traits could be related to intraspecific variation, we suggest caution when considering the faintness or roughness (i.e. the degrees of "development") of these muscle scars in phylogenetic or taxonomic evaluations. The inclusion of the character regarding "strong trapezoidal rugosity that extends over the caudal portion of the postacetabular process of the ilium" modified the topologies recovered in Cabreira et al. (2016), nesting CAPPA/UFSM 0200 with Chromogisaurus novasi and Saturnalia tupiniquim as a saturnaliin sauropodomorph, which suggests that this character (even though it is not the only character supporting Saturnaliinae) might actually result from ontogenetic variation, and, accordingly, would be reliable only for mature individuals. however, it is important to note that Buriolestes schultzi (ULBrAPVt280, CAPPA/UFSM 0035) also presents a rugosity in the postacetabular process of the ilium, but as it is less developed and more restricted than in saturnaliin sauropodomorphs, it was coded differently (this is also true for silesaurids and Herrerasaurus ischigualastensis). In summary, based upon carefully examination of several ilia of different early dinosaurs and dinosauromorphs, it is remarkable that muscle scars and/or rugosities are very variable between specimens of the same taxon (e.g. Buriolestes schultzi; Saturnalia tupiniquim). It is not clear if these variations result from ontogeny, sexual dimorphism or any other type of intraspecific variation, which makes a character based on this trait unstable and subjective. Nevertheless, the rugosities most likely present a phylogenetic signal, as they are absent in more advanced sauropodomorphs (e.g. Adeopapposaurus mognai Martínez 2009; Plateosaurus), which could indicate some heterochronical pattern, where even mature individuals possess the condition once present in juvenile early-diverging sauropodomorphs (i.e. absence of rugosities). Indeed, this seems a pedomorphic trait that could be related to the absence of a trochanteric shelf in the femora of all ontogenetic stages of mature individuals of post-Carnian sauropodomorphs. On the other hand, the trochanteric shelf comprises a muscle attachment absent in immature individuals, but present and well-developed in more mature individuals of Carnian sauropodomorphs (e.g. Buriolestes schultzi; Saturnalia tupiniquim; Nesbitt 2011, Müller et al. 2018a; see also Müller and Garcia 2019), for instance. therefore, the rugosities seem to work well in a broad phylogenetic context, but should be carefully considered at alpha taxonomic level. CONCLUSIONS the specimen herein described increases the dinosauromorph record for the Carnian from southern Brazil and represents the first dinosaur record from the Piche outcrop, which along with other sites from São João do Polêsine, rio Grande do Sul State, comprises one of the oldest dinosaurbearing units worldwide. CAPPA/UFSM 0200 presents some differences in comparison to coeval dinosaurs, and all the phylogenetic analyses herein performed consistently recovered CAPPA/UFSM 0200 as a saurischian dinosaur and potentially a saturnaliin sauropodomorph. Its incompleteness, however, prevents its nesting within a less-inclusive group. One of the character states (the presence of the abovementioned iliac rugosities) shared between CAPPA/UFSM 0200 and other saturnaliin sauropodomorphs might actually be result of intraspecific variation, such as ontogeny. Possible ontogenetic trends in the ilia of early-diverging sauropodomorphs show that these rugosities seem to have an ontogenetic signal, although histological analyses would be necessary to confirm maturity of the studied specimens. Finally, an increased sample of specimens is necessary to build a reliable ontogenetic series and improve the knowledge of comparative skeletal anatomy of these animals, and along with anatomical refinement, this would consequently shed light on the alpha taxonomy of early dinosaurs, a mandatory work to compile more reliable phylogenetic data on this fascinating group. (1): Saturnalia tupiniquim, Chromogisaurus novasi, CAPPA/UFSM 0200.