Attila Ősi

Hungarosaurus tormai, a new ankylosaur (Dinosauria) from the Upper Cretaceous of Hungary

Abstract A new ankylosaur Hungarosaurus tormai gen. et sp. nov. from the Upper Cretaceous (Santonian) Csehbánya Formation of the Bakony Mountains, western Hungary is described here. Among the four discovered specimens of this new armored dinosaur the best preserved is the most complete ankylosaur presently known from the Upper Cretaceous of Europe. Although many cranial characters of Hungarosaurus are not determinable, a preliminary phylogenetic analysis places Hungarosaurus in the Nodosauridae as a basal nodosaurid. Hungarosaurus is clearly distinguishable from Struthiosaurus on the basis of the dorsoventrally wide quadratojugal, the presence of bony protuberances on the quadratojugal and postorbital, the robust mandibular quadrate condyle, and the interpterygoid vacuity. The analysis suggests that Hungarosaurus appears to be more derived than Struthiosaurus, but more primitive than the North American Silvisaurus, Sauropelta, and Pawpawsaurus.

The First Freshwater Mosasauroid (Upper Cretaceous, Hungary) and a New Clade of Basal Mosasauroids

Mosasauroids are conventionally conceived of as gigantic, obligatorily aquatic marine lizards (1000s of specimens from marine deposited rocks) with a cosmopolitan distribution in the Late Cretaceous (90–65 million years ago [mya]) oceans and seas of the world. Here we report on the fossilized remains of numerous individuals (small juveniles to large adults) of a new taxon, Pannoniasaurus inexpectatus gen. et sp. nov. from the Csehbánya Formation, Hungary (Santonian, Upper Cretaceous, 85.3–83.5 mya) that represent the first known mosasauroid that lived in freshwater environments. Previous to this find, only one specimen of a marine mosasauroid, cf. Plioplatecarpus sp., is known from non-marine rocks in Western Canada. Pannoniasaurus inexpectatus gen. et sp. nov. uniquely possesses a plesiomorphic pelvic anatomy, a non-mosasauroid but pontosaur-like tail osteology, possibly limbs like a terrestrial lizard, and a flattened, crocodile-like skull. Cladistic analysis reconstructs P. inexpectatus in a new clade of mosasauroids: (Pannoniasaurus (Tethysaurus (Yaguarasaurus, Russellosaurus))). P. inexpectatus is part of a mixed terrestrial and freshwater faunal assemblage that includes fishes, amphibians turtles, terrestrial lizards, crocodiles, pterosaurs, dinosaurs and birds.

New Interpretation of the Palate of Pterosaurs

On the basis of a new, three‐dimensionally preserved specimen of the Early Jurassic pterosaur Dorygnathus banthensis we present a reinterpretation of the pterosaur palate. The hard palate is formed by the extensive palatal plate of the maxilla and not by the palatine as has been generally reconstructed. This palatal plate of the maxilla emarginates the choana rostrally and rostrolaterally as in other archosaurs and lepidosaurs. The longitudinally elongate and dorsoventrally flat palatine in Dorygnathus is an isolated bone caudal to the palatal plate of the maxilla and morphologically and topographically it resembles that of crocodilians and birds, respectively. The palatine separates the choana laterally from the suborbital fenestra demonstrating the homologous nature of the (primary) choana in all archosaurs and lepidosaurs. Our study indicates that in basal pterosaurs the pterygo–ectopterygoid fenestra existed caudal to the suborbital fenestra, which became confluent with the adductor chamber in pterodactyloids thereby increasing the relative size of the adductor chamber and hence the mass of the jaw adductors. The choana in basal pterosaurs was relatively small compared with the interpterygoid vacuity. With increasing rostroventral inclination of the quadrates in more derived pterosaurs, the interpterygoid vacuity was reduced considerably, whereas the choana increased in size. This exceptional Dorygnathus specimen also shows a hitherto unknown pair of fenestrae situated at the palatal contact of the premaxilla–maxilla and might represent the aperture for the vomeronasal organ. Anat Rec, 2010.

The first definitive record of a fossil bird from the Upper Cretaceous (Maastrichtian) of the Haţeg Basin, Romania

Located in southwestern Transylvania, Romania, the uppermost Cretaceous continental deposits of the Hat¸eg Basin are widely known for their well-preserved and diverse vertebrate fauna (e.g., Bojar et al., 2010; Grigorescu, 2010). Since the end of the 19th century, investigations of the fossiliferous continental deposits within the Hat¸eg Basin have revealed a wide range of preservation modes and taxa, including a large variety of small non-avian theropods (Weishampel and Jianu, 1996; Csiki and Grigorescu, 1998; Codrea et al., 2002; O? si and Fo? zy, 2007), several sites with dinosaur egg clutches and hatchlings (Grigorescu et al., 1990; Grigorescu, 1993; Weishampel et al., 1993; Codrea et al., 2002), a large pterosaur (Buffetaut et al., 2002), mammals (Grigorescu and Hahn, 1987; Csiki and Grigorescu, 2000; Codrea et al., 2002), and numerous other vertebrates (Folie and Codrea, 2005; Martin et al., 2006). It is thus surprising that bird remains have proved extremely rare within the Hat¸eg fauna. So far, only inconclusive records have been reported: Andrews (1913) first referred the proximal end of a femur and two distal tibiotarsi to Elopteryx nopcsai, a supposed pelecaniform bird. These tibiotarsi were later redescribed by Harrison and Walker (1975), who suggested that they belonged to two new taxa of Cretaceous owls (Strigiformes)—Bradycneme draculae and Heptasteornis andrewsi. However, the affinities of these bones have been much disputed and they are now generally regarded as belonging to non-avian theropods (Brodkorb, 1978; Elzanowski, 1983; Olson, 1985; Naish and Dyke, 2004; Kessler et al., 2005). Here, we present the first unequivocal evidence for a fossil bird in the Maastrichtian of the Hat¸eg Basin, a partial left tibiotarsus from the ‘middle member’ of the Densus¸-Ciula Formation (Fig. 1). The Maastrichtian age of these continental deposits is rather poorly constrained, as they overlie uppermost Campanian marine deposits (Melinte-Dobrinescu, 2010) and have yielded palynological assemblages indicative of a latest Cretaceous age (Antonescu et al., 1983; Csiki et al., 2008). The specimen (FGGUB [Faculty of Geology and Geophysics, University of Bucharest] R.1902) was discovered in the rich microvertebrate bonebed at Fˆantˆ anele, nearV? alioara (seeGrigorescu et al., 1999), in the northwestern part of the Hat¸eg Basin, preserved in drab, fine-grained deposits suggestive of a poorly drained floodplain environment.

The pterosaurian remains from the Grünbach Formation (Campanian, Gosau Group) of Austria: A reappraisal of 'Ornithocheirus buenzeli'

The fragmentary pterosaur material from the Campanian Grunbach Formation (Gosau Group) of Muthmannsdorf (Austria), previously identified as Ornithocheirus buenzeli Bunzel, 1871, is revised. A lower jaw fragment shows a helical type of articulation, which is known in several families of pterosaurs, and cannot be identified with great accuracy. The proximal part of a humerus shows distinctive features that allow it to be referred to as a member of the family Azhdarchidae, which is widespread in the Late Cretaceous Period of Europe. Ornithocheirus buenzeli is considered a nomen dubium . The pterosaur material from the Grunbach Formation cannot be used as evidence for the presence of ornithocheirids in the Late Cretaceous of Europe.

Potential For Intracranial Movements in Pterosaurs

Based on comparative anatomical, morphological, and phylogenetic considerations the potential of pterosaurs for cranial kinesis is assessed. Our investigation shows that whereas skeletally mature derived pterodactyloids have completely fused, rigid and doubtlessly akinetic skulls, skeletally immature derived pterodactyloids and more basal pterosaurs possess key features in the morphology of their otic and basal joints that are suggestive of cranial kinesis, namely streptostyly. In addition, pterosaurs exhibit an evolutionarily informative trend in the degree of cranial ossification, where it is low in most nonpterodactyloids (here named bifenestratans), intermediate in Rhamphorhynchus and Archaeopterodactyloidea, and high in derived pterodactyloids. Incomplete fusion could also indicate loose connections between skull elements. However, another crucial anatomical requirement of a kinetic skull, the permissive kinematic linkage is absent in all pterosaurian taxa. The fact, that the presence of permissive kinematic linkages in the skull is also a prerequisite of all types of cranial kinesis, provides hard evidence that all members of Pterosauria had akinetic skulls. Thus, the presence of the morphological attributes indicative of intracranial movements in some pterosaurs must be explained on grounds other than real potential for cranial kinesis. It could either be of mechanical or ontogenetic importance, or both. Alternatively, it might be considered as the morphological remnant of a real, kinetic skull possessed by the diapsid ancestors of pterosaurs. Anat Rec, , 2011.

Diversity and convergences in the evolution of feeding adaptations in ankylosaurs (Dinosauria: Ornithischia)*

Abstract Ankylosaurian dinosaurs were low-browsing quadrupeds that were traditionally thought of as simple orthal pulpers exhibiting minimal tooth occlusion during feeding, as in many extant lizards. Recent studies, however, have demonstrated that effective chewing with tooth occlusion and palinal jaw movement was present in some members of this group. Qualitative and quantitative analysis of feeding characters (i.e. craniodental features, tooth wear patterns, origin and insertion of jaw adductors) reveal at least three different jaw mechanisms during the evolution of Ankylosauria. Whereas, in basal members, food processing was restricted to simple orthal pulping, in late Early and Late Cretaceous North American and European forms a precise tooth occlusion evolved convergently in many lineages (including nodosaurids and ankylosaurids) complemented by palinal power stroke. In contrast, Asian forms retained the primitive mode of feeding without any biphasal chewing, a phenomenon that might relate to the different types of vegetation consumed by these low-level feeders in different habitats on different landmasses. Further, a progressive widening of the muzzle is demonstrated both in Late Cretaceous North American and Asian ankylosaurs, and the width and general shape of the muzzle probably correlates with foraging time and food type, as in herbivorous mammals.

Hettangian (Early Jurassic) Dinosaur Tracksites from the Mecsek Mountains, Hungary

Isolated theropod dinosaur tracks were first collected in Hungary from Hettangian (Lower Jurassic) beds of the Mecsek Coal Formation in 1966 and described as Komlosaurus carbonis Kordos, 1983. Our study is based on newly collected material from additional track-bearing beds. The description of the two largest preserved surfaces containing a total of 102 tracks that can be referred to as 21 trackways is provided here. This represents the first attempt to measure, map and compare the tracks of these bipedal, functionally tridactyl dinosaurs in several associated trackways. Significant morphological variability can be observed (e.g., depth, presence or absence of a metatarsal impression, digit length, digit divarication angle) that is explained by differences in physical parameters of the substrate. The mean of pes length is 16.3 cm in tracksite PB1 and 19.9 cm in tracksite PB2. Stride length of trackways usually ranges between 120 and 170 cm; pace angulation is 160–175°. The speed of the trackmaker is calculated to range between 6 and 14 km/h. Imprints are diagnosed by a pes length/width ratio lower than 2.0; metatarsal pads and hallux impressions are frequent. Based on the similarity of several morphological characters, the herein described tracks are referred to the ichnotaxon Komlosaurus carbonis, which is clearly distinct from Grallator and Kayentapus.

An enigmatic crocodyliform tooth from the bauxites of western Hungary suggests hidden mesoeucrocodylian diversity in the Early Cretaceous European archipelago

Background. The Cretaceous of southern Europe was characterized by an archipelago setting with faunas of mixed composition of endemic, Laurasian and Gondwanan elements. However, little is known about the relative timing of these faunal influences. The Lower Cretaceous of East-Central Europe holds a great promise for understanding the biogeographic history of Cretaceous European biotas because of the former proximity of the area to Gondwana (as part of the Apulian microcontinent). However, East-Central European vertebrates are typically poorly known from this time period. Here, we report on a ziphodont crocodyliform tooth discovered in the Lower Cretaceous (Albian) Alsópere Bauxite Formation of Olaszfalu, western Hungary. Methods. The morphology of the tooth is described and compared with that of other similar Cretaceous crocodyliforms. Results. Based on the triangular, slightly distally curved, constricted and labiolingually flattened crown, the small, subequal-sized true serrations on the carinae mesially and distally, the longitudinal fluting labially, and the extended shelves along the carinae lingually the tooth is most similar to some peirosaurid, non-baurusuchian sebecosuchian, and uruguaysuchid notosuchians. In addition, the paralligatorid Wannchampsus also possesses similar anterior teeth, thus the Hungarian tooth is referred here to Mesoeucrocodylia indet. Discussion. Supposing a notosuchian affinity, this tooth is the earliest occurrence of the group in Europe and one of the earliest in Laurasia. In case of a paralligatorid relationship the Hungarian tooth would represent their first European record, further expanding their cosmopolitan distribution. In any case, the ziphodont tooth from the Albian bauxite deposit of western Hungary belongs to a group still unknown from the Early Cretaceous European archipelago and therefore implies a hidden diversity of crocodyliforms in the area.

A new large-bodied thalattosuchian crocodyliform from the Lower Jurassic (Toarcian) of Hungary, with further evidence of the mosaic acquisition of marine adaptations in Metriorhynchoidea

Based on associated and three-dimensionally preserved cranial and postcranial remains, a new thalattosuchian crocodyliform, Magyarosuchus fitosi gen. et sp. nov. from the Lower Jurassic (Upper Toarcian) Kisgerecse Marl Formation, Gerecse Mountains, Hungary is described here. Phylogenetic analyses using three different datasets indicate that M. fitosi is the sister taxon of Pelagosaurus typus forming together the basal-most sub-clade of Metriorhynchoidea. With an estimated body length of 4.67–4.83 m M. fitosi is the largest known non-metriorhynchid metriorhynchoid. Besides expanding Early Jurassic thalattosuchian diversity, the new specimen is of great importance since, unlike most contemporaneous estuarine, lagoonal or coastal thalattosuchians, it comes from an ‘ammonitico rosso’ type pelagic deposit of the Mediterranean region of the Tethys. A distal caudal vertebra having an unusually elongate and dorsally projected neural spine implies the presence of at least a rudimentary hypocercal tail fin and a slight ventral displacement of the distal caudal vertebral column in this basal metriorhynchoid. The combination of retaining heavy dorsal and ventral armors and having a slight hypocercal tail is unique, further highlighting the mosaic manner of marine adaptations in Metriorhynchoidea.