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Scipionyx samniticus (Theropoda: Compsognathidae) from the Lower Cretaceous of Italy. Osteology, ontogenetic assessment, phylogeny, soft tissue anatomy, taphonomy and paleobiology
... Reconstructing the diet and possible feeding habits of extinct animals is one of the major tasks for modern paleobiology [1]. While direct indicators such as stomach and intestinal contents[2-4], gastric pellet [5,6], and coprolites[7-9], can reveal diets, these are rarely preserved unless non-digestive hard tissues including bone fragments [2][3][4]9], seed coats [10,11]or plant fragments[7] are present[11-13]. This makes carnivores[3] (including osteophagus[8, 9] and piscivorous[5]), granivores[10] and frugivores[14, 15] easier to be identified in the fossil record. ...
... Further preparation of the type specimen of Bannykus wulatensis revealed a three-dimensionally preserved posterior gastralia ribcage, indicating minimal mechanical disturbance to the abdominal region since death. A yellowish conglomerate beneath the last dorsal vertebrae, corresponding to the duodenum-to-rectum region seen in Scipionyx samniticus [2] and Sinocalliopteryx gigas [28], is enclosed by the gastralia (Fig. 1). The distinct color and heterogeneous texture of this conglomerate compared to the surrounding greyish-green sandstone ( Fig. 1, b-d) suggest that some abdominal contents, including food remains, may have been preserved in situ. ...
... 2-3, Extended Data Table 1), primarily in the forms of apatite (with the phosphorus elemental map serving as a proxy for calcium phosphate [6,29]). This result is consistent with findings from other bone-rich intestinal contents [2,6,29] or coprolites [8,29]. In contrast, the host sandstone contains heavy minerals such as ilmenite and hematite (Figs. ...
A dietary shift from carnivory to insectivore has been proposed to explain the dramatic morphological evolution of alvarezsaurians, particularly the adaptation related to the manual digital reduction and body size miniaturization. However, based solely on morphological shifts, this hypothesis lacked direct dietary evidence to support either carnivory or insectivore. Here, we present the first convincing dietary evidence for alvarezsaurians, derived from the intestinal contents of the Early Cretaceous Bannykus wulatensis. Our analysis revealed significantly higher levels of calcium and phosphorus in the intestinal contents compared to the surrounding sandstone. Scanning electron microscopy identified hard tissue debris and possible soft tissues surrounding by phosphatized bacteria and tightly packed hollow microspheres, suggesting that the intestinal contents were strongly pseudomorphed by phosphatized microbes during fossilization. Raman spectroscopy showed characteristic peaks indicative of bone-derived material, consistent with the hard tissue debris appeared in the intestinal contents. Our results suggest that Bannykus had a carnivorous diet with strong chemical digestion, which likely compensated for its delicate cranial structures and small teeth. These results imply that if a dietary shift to insectivore occurred, it likely took place later in alvarezsaurian evolution, probably coinciding with a reduction in body size.
... Ostrom (1978) suggested an immature status for the Compsognathus holotype and questioned the validity of a "coelurosaurian group" including all gracile-limbed small-sized theropods. Yet, the referral of Compsognathus to Coelurosauria persisted after the application of the phylogenetic systematics (Hennig, 1966) to dinosaur taxonomy, and has never been questioned by the numerous analyses focusing on theropod relationships (e.g., Gauthier, 1986;Holtz et al., 2004;Hwang et al., 2004;Choiniere et al., 2013;Brusatte et al., 2014;Dal Sasso & Maganuco, 2011). During the last three decades, newly discovered theropods have dethroned Compsognathus from the iconic status of the "smallest dinosaur" (Xu et al., 2000). ...
... During the last three decades, newly discovered theropods have dethroned Compsognathus from the iconic status of the "smallest dinosaur" (Xu et al., 2000). Furthermore, other taxa have been included in the compsognathid lineage or have been suggested to be members of the same coelurosaurian grade: Sinosauropteryx (Chen et al., 1998;Chen & Currie, 2001); Scipionyx (see Dal Sasso & Maganuco, 2011); Huaxiagnathus (Hwang et al., 2004); Mirischia (Naish et al., 2004); Juravenator (Göhlich & Chiappe, 2006); Sinocalliopteryx (Ji et al., 2007;Xing et al., 2012); and Xunmenglong (Xing et al., 2019). A specimen referred to Sinosauropteryx by Currie & Chen (2001), NGMC 2124, differs in several features from the former and represents a distinct taxon (Longrich, 2002). ...
... All the valid compsognathid taxa share with the eponymous genus a small body size (in all cases, less than 2.5 meters in length, often less than 1.5 meters), and a proportionally large skull which bears enlarged orbits, is devoid of specializations and lacks cranial ornamentations. Despite the generalized body plan, compsognathids show a few peculiarities including a characteristic shape of the tooth crowns (Peyer, 2006), slender ("hair-like") cervical ribs, fan-shaped dorsal neural spines, moderately short forelimbs, and relatively elongate proportions of the hindlimbs (Hwang et al., 2004;Dal Sasso & Maganuco, 2011). Yet, they show a significant intra-clade diversity in several elements of the skeleton, including the snout and cheek bones, the vertebrae, and in the forelimb proportions (pers. ...
Known since the 19 th Century, the compsognathids are among the smallest predatory dinosaurs, and include the first feathered non-avian species found. Traditionally, compsognathids have been considered small and unspecialized coelurosaurs, closer to birds than large-bodied forms like allosauroids and megalosaurids. Yet, all known compsognathids are based on skeletally-immature specimens, and this challenges the accuracy of their traditional phyletic placement. Despite the role of heterochrony in dinosaur evolution is widely recognized, the impact of ontogenetic-biased miscodings in shaping theropod phylogenetics is mostly underestimated. Herein, I show that the standard framework of theropod macroevolution is biased by a series of coding artifacts which violate semaphoront equality prescribed by phylogenetic systematics. I introduce "Ontogenetic State Partitioning" (OSP), a novel coding protocol which integrates ontogenetic and morphological variation under a total evidence approach, and apply it to a densely sampled data set focusing on Mesozoic theropods. The phylogenetic analysis dismissed "Compsognathidae" from being a natural group: its members are identified as juvenile morphs nested among several non-maniraptoriform tetanuran lineages. Conservatism in the immature body plan and greater disparity among large-sized adults differentiate the predatory communities dominated by non-coelurosaurian species (e.g., the so called "triumvirates") from the maniraptoriform-tyrannosaurid faunas (herein named "tyrannies"). This clade-specific differentiation among the communities is confirmed by an analysis of the predatory guild structures including all growth stages: triumvirates and tyrannies result as particular cases along a continuum of communities regulated mainly by alternative contributions of the small-and medium-sized classes. The oldest tyrannies (early Late Cretaceous in age) cluster among non-tyranny communities, supporting the hypothesis that tyrannosaurid-dominated faunas acquired their peculiar structure only after the extinction of the non-coelurosaurian components. The macroevolutionary trajectory that led the maniraptoriforms to realize the avian-like biology may have precluded them from occupying hypercarnivorous large-bodied niches: this bauplan constraint would have favored the tyrannosauroids in opportunistically assuming the apex predatory roles in Late Cretaceous Asiamerica but not elsewhere. The large-scale structure of the Cenozoic radiation of birds is coherent with the framework introduced herein.
... However, there is limited information available on juvenile coelurosaurian theropods. Regarding non-coelurosaurian tetanurans, early ontogenetic stages are known in taxa such as Scipionyx and Juravenator, both of which have preserved femora (Göhlich and Chiappe 2006;Chiappe and Göhlich 2010;Dal Sasso and Maganuco 2011). In these taxa, however, the greater and lesser trochanters are separated. ...
A new specimen, MAU-Pv-PH-453, comprising an isolated femur from the Plottier Formation (Coniacian-Santonian), northern Patagonia, is described here. Its characteristics, i.e., an anteriorly curved diaphysis; fused lesser and greater trochanters forming a trochanteric crest; a prominent medially directed head; and the absence of a fourth trochanter, allow us to identify it as belonging to a maniraptoran theropod. Among Patagonian maniraptorans, MAU-Pv-PH-453 shares similarities with alvarezsaurians, such as the absence of a posterior trochanter, a trochanteric shelf, and the fourth trochanter. However, in Patagonian alvarezsaurs, the lesser and greater trochanters are generally separated by a cleft. Notably, MAU-Pv-PH-453 exhibits some features seen in femora of parvicursorine alvarezsaurids, including a proximally projected trochanteric crest and an L-shaped profile in proximal view. However, MAU-Pv-PH-453 presents differences with parvicursorines, such as a knob partially separating the lesser and greater trochanters. Phylogenetically, MAU-Pv-PH-453 may have parvicursorine affinities, although its fragmentary nature might generate a bias in its phylogenetic position. Due to the lack of more diagnostic characters, MAU-Pv-PH-453 is assigned to Alvarezsauria indet. This material represents the second theropod record from the Plottier Formation and it could fill a temporal gap (between Coniacian and Santonian) in the record of Upper Cretaceous Patagonian alvarezsaurians.
... Fluorescence induced by ultraviolet light (365 nm) was used to better see organic remains and highlight their chemical compositional differences, following previous studies (e.g. Tischlinger 2002;Hone et al. 2010;Dal Sasso and Maganuco 2011;Crippa and Masini 2022). Scanning electron microscopy (SEM) images and elemental peaks were obtained by analyzing microsamples, taken from carefully selected areas of the specimen, with a Jeol JSM 5610 LV (IXRF Systems Inc.) equipped with an EDS 500 spectrometer. ...
The first Mesozoic scorpion from Italy, Protobuthus ziliolii sp. nov., is here described and named thanks to a single specimen. This new species comes from the Besano Formation (Middle Triassic) of Monte San Giorgio, a UNESCO World Heritage Locality (WHL). Taphonomical analysis allows interpretation of the specimen as a full-body fossil, rather than an exuvia. Different analytical techniques, such as optical, UV, and SEM microscopy, reveal different characters, not visible together with a single method. The new species is assigned to the family Protobuthidae. Protobuthus ziliolii is the first arachnid to be reported from the Besano Formation and the Mesozoic of Italy, the second from the Monte San Giorgio WHL, and the second species of the genus Protobuthus in the world. This discovery corroborates the previously hypothesized nearshore deposition for the genesis of the upper portion of the Besano Formation.
The Compsognathidae was originally considered an early-diverging clade of coelurosaur theropods. However, recent study suggests that Compsognathidae is not monophyletic. Here, we describe two new compsognathid-like species, Sinosauropteryx lingyuanensis sp. nov. and Huadanosaurus sinensis gen. et sp. nov. from the Lower Cretaceous Yixian Formation of Dawangzhangzi (Lingyuan, western Liaoning, China). The phylogenetic results indicate that all compsognathid-like theropods from the Early Cretaceous Jehol Biota form a monophyletic group Sinosauropterygidae nested among early-diverging coelurosaurs. Morphological comparison between various species of sinosauropterygids from the Early Cretaceous of Northeast China, combined with the phylogenetic results, suggests that at least three distinct hunting strategies were present among coeval species. The diversification of theropods should be attributed to the landscape caused by the North China craton destruction.
This study was carried out with a multidisciplinary approach to define a method for improving territorial revitalization through enhancing the paleontological heritage, highlighting potentialities in promoting territorial valorization, particularly for inner areas. The methodology is applied to the Pietraroja site in the Campania region, which was selected because of its large scientific significance for palaeontology and geology. The Pietraroja site (Benevento) is universally known as the place in which the fossil of a small dinosaur, Scypionix samniticus, was found. This study mainly aims to broaden the fruition of the Pietraroja site by designing and creating immersive digital environments allowing for remote access from all over the world via the Internet. In this regard, innovative technologies such as virtual reality, mixed reality, and augmented reality have been utilized to set up digital spaces for visitors who can explore the features of the cultural site and appreciate its high cultural value. The adoption of these new technologies represents the way to propose to the public the cultural contents of the Pietraroja site and to tell the story of the formation of the place.
Noasaurus leali is a small (~2 m) carnivorous theropod and the nominal genus of the clade Noasauridae, one of the two radiations of abelisauroid ceratosaurs predominantly present in the Southern Hemisphere during the Mesozoic. This eponymous theropod from the Maastrichtian Lecho Formation of Salta, Argentina, is known from an incomplete skeleton of which the strongly curved manual ungual is the most peculiar element. We here provide for the first time a comprehensive description of the holotypic specimens of Noasaurus, whose phylogenetic position was explored using three independent datamatrices on theropod relationships. This species is diagnosed by several apomorphies such as a dorsal ridge in the maxillary fossa, a strongly arched quadrate, a cervical neural arch with anterior epipophyseal prongs, and a manual ungual with a subtriangular flexor fossa delimited by a V-shaped ridge. Results of the phylogenetic analyses recovered Noasaurus closely related to Velocisaurus, Masiakasaurus, and Laevisuchus, which together form a Late Cretaceous radiation of small-bodied noasaurids restricted to the Southern Hemisphere. The peculiar morphology of the lateral dentition and manual unguals suggests that Noasaurus was an opportunistic carnivore feeding on small prey items and a possible piscivore gaffing fish with its specialized hand claws.
Members of the dinosaur clade Spinosauridae had numerous traits attributed to feeding in or around water, and their feeding apparatus has often been considered analogous to modern crocodylians. Here we quantify the craniodental morphology of Spinosauridae and compare it to modern Crocodylia. We measured from spinosaurid and crocodylian skeletal material the area of alveoli as a proxy for tooth size to determine size‐heterodonty. Geometric morphometrics were also conducted on tooth crowns and tooth bearing regions of the skull. Spinosaurids overall had relatively large alveoli, and both they, and crocodylians, had isolated regions of enlarged alveoli. Spinosaurines also had enlarged alveoli along the caudal dentary that baryonychines lacked, which instead had numerous additional caudal tooth positions. Size‐heterodonty was positively allometric, and spinosaurids overlapped with generalist/macro‐generalist crocodylians of similar sizes. Spinosaurid crown shape morphologies overlapped with certain slender‐longirostrine crocodylians, yet lacked molariform distal crowns typical of most crocodylians. Spinosaurid rostra and mandibles were relatively deep with undulating margins correlating with local tooth sizes, which may indicate a developmental constraint. Spinosaurines had a particularly long concavity caudal to their rosette of anterior cranial teeth, with a corresponding bulbous rostral dentary. The spinosaurid feeding apparatus was well suited for quickly striking and creating deep punctures, but not cutting flesh or durophagy. The jaws interlocked to secure prey and move it deeper into the mouth. The baryonychines probably did little oral processing, yet spinosaurines could have processed relatively large vertebrates. Overall, there is no indication that spinosaurids were restricted to fish or small aquatic prey.
This study reports the first high‐resolution, integrated facies analysis of the lowermost Albian Pietraroja Lagerstätten (Apennine Carbonate Platform) which yields the first dinosaur ( Scipionyx samniticus ) found in Italy and other terrestrial vertebrates and plants. Aiming to clarify the long‐debated palaeoenvironmental significance of the Pietraroja succession, the following have been carried out: (i) a field survey to establish stratigraphic position and number of the fossil Lagerstätten; (ii) the centimetre‐scale facies analysis of a new section, ca 15 m‐thick, consisting of two new lithostratigraphic units, the ‘Cyclically organized Limestones’ and the ‘Cherty Limestones’ ; (iii) the scanning electron microscopy – energy dispersive X‐ray spectroscopy and backscattered electron – energy dispersive X‐ray spectroscopy analyses of clay mineral proxies for palaeoclimate and non‐carbonate grains; and (iv) the regional and supra‐regional investigation of the event stratigraphical context of the fossil Lagerstätten, in order to elucidate the controls on their formation. The section includes two out of the three observed fossil‐rich Lagerstätten, each up to 1.5 m‐thick. The arrangement of lithofacies and early diagenetic overprint defines shallow‐water depositional cycles suggestive of precession and short‐eccentricity periodicities. The Middle Lagerstätte yielding Scipionyx samniticus consists of three intervals. The lower, paralic interval was deposited during arid conditions and passes gradually to the plant‐rich, coastal wetland carbonaceous marls of the upper interval. The ‘ Cherty Limestones’ , yielding the Upper Lagerstätte with terrestrial vertebrates, contains two spiculitic intervals suggesting the development of siliceous sponge meadows in a shallow, restricted lagoon. Genetic stratigraphy suggests that the Pietraroja Lagerstätten were formed during glacioeustatic lowstands; interestingly, the Middle Lagerstätte mirrors the earliest Albian sea‐level lowstand (KAl1 event, ca 111.2 Myr), during a semi‐continuous supply of windblown volcaniclastics. Findings herein substantiate the pivotal role of paralic‐continental Lagerstätten for deriving high‐frequency palaeoclimatic dynamics and glacioeustacy from carbonate platform archives. The origin of Tethyan continental bridges between Africa and Europe during the late Aptian–earliest Albian cold interval is discussed.
Some Cretaceous dinosaur taxa with a broad enough record on the continents of the northern hemisphere (Laurasia) or in the southern continents (Gondwana) have been interpreted as Laurasian or Gondwanan in origin. The occasional presence of these taxa outside Laurasia or Gondwana respectively has frequently been explained in terms of dispersal from their place of origin by means of land bridges that are indeterminate in location and character. One example of such a dispersal event is provided by the Early Cretaceous dinosaurs of Europe and Africa. Certain European taxa have been interpreted as having their origin in Gondwana. If we regard these presences common to both areas as being the result of a point of communication between Laurasia and western Gondwana or at least of sporadic flows in both directions during the Early Cretaceous, we may opt for dispersal as an explanation.
It has been assumed that there was an intercontinental bridge between Africa and Europe passing through the archipelago of which Iberia formed a part. This interpretation emerged from the idea that such a bridge existed in the Late Jurassic, explaining the presence of similar ornithopod dinosaurs in Africa and Europe. However, from the end of the Early Jurassic a period of “rift” began on the southern Iberian margin, entailing the formation of a sedimentary furrow with pelagic sedimentation in what is known as the Subbetic zone. Moreover, the differences in the observed dinosaur fauna between western Gondwana and the Iberian Peninsula in the Neocomian can be explained as the result of endemism and regional extinctions. The archipelago that formed the Iberian plate was Laurasia’s closest continental mass to Gondwana during the Neocomian, yet there was still a separation of several hundred kilometres of open ocean without islands. Such a barrier would seem difficult for dinosaurs to overcome. As such, we lack proof of communication between the two supercontinents via Iberia during the Neocomian.
The situation appears to change in the Barremian-Aptian transition. Some of the taxa present in the Hauterivian-Barremian of Europe are recorded in Gondwana from the Aptian onwards. This can possibly be explained in terms of the more complete record that exists, but it cannot be ruled out that a communication was established between Gondwana and Laurasia at the end of the Barremian. For the time being, we lack geological support for this bridge in Iberia, yet it might be located in Apulia, where there is a great development of shallow-shelf carbonates with dinosaur remains from the period in question.