Continental Vertebrate Research Articles

Meeting Island Dwarfs and Giants of the Cretaceous – The Hațeg Country UNESCO Global Geopark, Romania

We review here key geological heritage elements of the Hațeg Country UNESCO Global Geopark (Southern Carpathians, western Romania) represented by latest Cretaceous continental vertebrate fossils and the sedimentary rocks enclosing them. Based on available geological and paleontological evidence, these animals were living on a tropical island. This paleogeographic setting led to the development of some unusual paleobiological traits including dwarfing of the dinosaurs, high levels of endemism, relictual characteristics, as well as uniquely derived anatomical, developmental, metabolic and/or sensory features. These unique characteristics led to the establishment of the Hațeg Country UNESCO Global Geopark over a decade ago. Recently, the Geopark implemented several projects including specific ‘Dinosaur Island’-related thematic trails and visits to key geoheritage elements. We focus on four key fossiliferous areas of the Geopark, highlighting the most important geoheritage elements of each, as well as the most significant geoproducts created based on these particular elements.

A Unique Late Cretaceous dinosaur locality in the Bakony-Balaton Geopark of Hungary (Iharkút, Bakony Mts.)

Iharkut is a Late Cretaceous (Santonian) vertebrate-bearing locality in the Bakony Mountains of western Hungary, where productive and continuous paleontological excavations have been carried out in the last twenty years. Field work resulted in a very rich and diverse assemblage of terrestrial and freshwater animals (fishes, amphibians, turtles, lizards, a freshwater mosasaur, pterosaurs, crocodilians, dinosaurs including birds). This abundance and diversity of fossil taxa plays a significant role in the understanding of the evolutionary history of European Late Cretaceous continental vertebrate faunas. Furthermore, due to its palaeogeographic position (in the western Tethyan archipelago) and its Santonian age, the locality fills an important gap in the Late Cretaceous record of continental vertebrates in Europe. The locality is among the geological values of the Bakony-Balaton UNESCO Global Geopark. The uniqueness of the fossils raises this locality into the list of high priority geoheritage sites of the world, which draws the attention of both scientific and non-scientific geopark visitors.

A new latest Cretaceous pleurodiran turtle (Testudinata: Dortokidae) from the Haţeg Basin (Romania) documents end-Cretaceous faunal provinciality and selective survival during the K-Pg extinction

Dortokidae is an endemic family of stem-pleurodiran turtles, known exclusively from the Cretaceous and early Paleogene of Europe. Here we describe a new dortokid taxon from the Upper Cretaceous (Maastrichtian) Sînpetru Formation of the southern Haţeg Basin, Romania. The type material of Dortoka vremiri sp. nov. comprises a well-preserved carapace and a nearly complete plastron as well as the in situ right scapula and right pubis. Phylogenetic analyses performed to assess the position and interrelationships of Dortoka vremiri sp. nov. within Dortokidae as well as within the wider Pleurodira recovered the new taxon firmly nested within Dortokidae, and together with other dortokids, placed along the stem lineage of pleurodires. Our analysis provides evidence for allopatric speciation in Dortoka through the presence of two distinct lineages – an eastern and a western European lineage, respectively. A similar east/west disjunct distribution pattern has also been established previously for several vertebrate groups such as other turtles, dinosaurs and mammals, probably resulting from isolation due to the particular palaeogeographical setting of the Late Cretaceous European Archipelago. The phylogeny demonstrates local survival of Dortoka across the K-Pg boundary as the sister-taxon of D. vremiri is D. botanica from the uppermost Paleocene deposits of Romania and points to geographical selectivity, as the western lineage of Dortoka went extinct before the Paleogene. Osteology and novel taphonomical data imply a semi-terrestrial lifestyle for Kallokibotion bajazidi, a turtle occurring in coeval faunas with the aquatic and smaller-sized D. vremiri and most likely going extinct at the K-Pg boundary. Altogether, this pattern is consistent with selective extinction of terrestrial taxa previously observed for other continental vertebrate assemblages across the end-Cretaceous mass extinction with only two other examples from turtles. http://zoobank.org/urn:lsid:zoobank.org:pub:871AD436-9448-40C6-85A4-0213CBC04A29

A fossil terrestrial fauna from Tobène (Senegal) provides a unique early Pliocene window in western Africa

Early Pliocene hominin evolutionary scenarios proposed to date mostly rely on paleontological investigations from eastern Africa. Filling major geographical gaps in the fossil record could potentially invalidate these scenarios and stimulate development of improved theories. Based on published literature, no Pliocene fossil of continental vertebrates have been discovered in Western Africa and the situation is only slightly better in central and northern Africa. Here, we expand the Pliocene vertebrate continental fossil record to western Africa with the description of the Tobène fauna, a new fossiliferous Neogene locality from Senegal. We describe a diversity of large mammals, including at least ten taxa based on fragmentary remains recovered from alluvial channel deposits. Estimation based on weathering events and biochronology suggests an early Pliocene age. Most of these mammalian taxa were widely distributed over the African continent during the early Pliocene. Possible faunal correlations with eastern African localities call for continent-wide paleontological investigations.***************

AN OVERVIEW ON THE LATE MIOCENE VERTEBRATES FROM THE FISSURE FILLINGS OF MONTICINO QUARRY (BRISIGHELLA, ITALY), WITH NEW DATA ON NON-MAMMALIAN TAXA

The latest Messinian Monticino Quarry fissure fillings, near Brisighella in Italy, are well known for their diverse mammal fauna. Conversely, little is known about other vertebrates from this rich site. Beside presenting an overview of the mammals, here we describe fish, amphibian, reptile, and bird remains, identifying three, eight, at least 18, and five taxa, respectively. Some of these represent the oldest occurrences either worldwide (an erycine snake related to Eryx jaculus, Malpolon, and otidids birds) or locally (common toads in the Apennine Peninsula and eremiadine lacertids in Europe, the latter being also the only known occurrence of these lizards in Italy). Altogether, the vertebrate fauna from Monticino Quarry is indicative of a complex palaeoenvironment, which was warm and somehow dry. Water bodies were indeed present though, as well as a patchy set of habitats with loose or sandy soils, rocky outcrops, open biotopes, and (even though maybe to a lesser extent) wooded areas. Furthermore, estuarine or lagoonal conditions were likely present near the depositional site. From a palaeobiogeographical point of view, the non-mammal vertebrate assemblage from Monticino Quarry shows considerable Afro-Asian affinities at least for some components. In the context of the Italian late Miocene continental vertebrate assemblages, that of Monticino is remarkably similar to those from the Piedmont Basin, especially if compared with the Tusco-Sardinian area, Apulian Platform, Calabrian Arc and Sicily. This is consistent with the palaeobiogeographic scenario defined by mammal assemblages, with northcentral Italy, Tuscany and Sardinia, Apulian Platform, and Calabria and Sicily representing separated bioprovinces.

First occurrence of Doswellia cf. D. kaltenbachi (Archosauriformes) from the Late Triassic (middle Norian) Chinle Formation of Arizona and its implications on proposed biostratigraphic correlations across North America during the Late Triassic

ABSTRACT Doswellia kaltenbachi is a long-snouted non-archosaur archosauriform known from the Late Triassic of the United States (Virginia and Texas). New material from the Chinle Formation of Arizona represents the first occurrence of D. cf. D. kaltenbachi from that formation and state. This occurrence is from the type section for the Adamanian estimated holochronozone (Late Triassic: middle Norian) in Petrified Forest National Park and firmly establishes the presence of this taxon in the Adamanian. This occurrence adds to the diverse vertebrate assemblage of the upper part of the Blue Mesa Member of the Chinle Formation (Adamanian). More broadly, the new occurrence strengthens biogeographic links to the older (latest Carnian or earliest Norian) Otischalkian from Texas and the possibly older Sanfordian/Conewagian assemblages of Virginia. The spatiotemporal distribution of Doswellia underscores the similarity of North American continental vertebrate assemblages across the Carnian–Norian boundary prior to the Adamanian–Revueltian boundary.

A detailed osteological description of Xenotarsosaurus bonapartei (Theropoda: Abelisauridae): implications for abelisauroid phylogeny

Xenotarsosaurus bonapartei was the third abelisaurid theropod dinosaur to be named from Argentina. The holotype comprises two partial anterior dorsal vertebrae and a nearly complete right hind limb from the Upper Cretaceous (lower Cenomanian–upper Turonian) Bajo Barreal Formation, central Patagonia, Argentina. The materials display morphological features that undoubtedly position Xenotarsosaurus within Abelisauroidea. Moreover, detailed comparisons with members of that theropod group confirm the close relationship of this taxon to abelisaurids. Here we provide an emended diagnosis of Xenotarsosaurus bonapartei that includes five newly recognized autapomorphies: (1) anterior dorsal vertebrae with large, strongly dorsoventrally developed parapophyses; (2) anterior dorsal vertebrae with well-developed centroprezygapophyseal fossae that are taller dorsoventrally than wide mediolaterally; (3) fibular condyle of femur triangular in shape and projecting posteriorly; (4) well-marked groove on anterolateral corner of proximal fibula; and (5) iliofibularis tubercle of fibula distally interrupted by hook-like concavity. To determine its systematic position within Abelisauroidea, we incorporated Xenotarsosaurus into a phylogenetic analysis, recovering this theropod as a non-carnotaurine abelisaurid more derived than Eoabelisaurus mefi. Xenotarsosaurus displays several plesiomorphic traits when compared with penecontemporaneous abelisaurids from the Neuquén Group. Similarly, other non-avian dinosaur taxa from the Bajo Barreal Formation are frequently postulated as more phylogenetically basal than coeval forms from northern Patagonia. This scenario suggests the potential existence of provincialism in early Late Cretaceous continental vertebrate faunas of southern South America. The present study increases knowledge of abelisaurid systematics, evolution, and paleobiogeography and augments our understanding of the Upper Cretaceous dinosaur assemblage of central Patagonia.

Drivers of change and conservation needs for vertebrates in drylands: an assessment from global scale to Sahara-Sahel wetlands

Drylands range across more than half of the global terrestrial area and harbour about a quarter of continental vertebrate species, many of them endemic. However, this fauna is being increasingly threatened, in particular the one that inhabits deserts, one of the last biomes on earth. This work tracks the most relevant global change drivers acting on drylands, especially in deserts and arid regions, the conservation actions being developed, and the research needs for vertebrate conservation, following IUCN standardised classification schemes. Using the Sahara-Sahel wetlands as case study, it is provided a detailed examination of these aspects to support regional biodiversity conservation and human welfare. Deserts and arid regions are threatened by the synergistic effects of increasing development of urban areas, agriculture, energy production, mining, transportation and service corridors, resulting in pollution, invasive species, human intrusions and disturbance, biological resource overuse and in general, natural system modifications. In addition, climate change together with social underdevelopment of many desert-range countries places the mitigation of threat factors in a large and complex web of global-local societal challenges. Conservation actions targeting land/water and species protection and management, as well as education, awareness, capacity building, and legislation measures to increase livelihood development, are being developed. Additional research efforts are need to enhance biodiversity conservation planning, monitoring biodiversity and land-degradation status (based on Essential Biodiversity Variables), and quantification of socioeconomic factors associated with sustainable use of natural resources and human development. Sahara-Sahel wetlands are important life-support systems for both humans and vertebrates, the last vulnerable to listed global threats. They offer framework scenario to revert current environmental and societal challenges in deserts. Long-term conservation of desert vertebrate biodiversity requires appropriate policy instruments to promote sustainable use of natural resources. Raising environmental alertness within local communities of uniqueness of desert biodiversity is needed to promote policy change.

New middle Miocene (Langhian - Serravallian) vertebrate localities in northwestern Patagonia, Argentina: A contribution to high latitude south american land mammal ages sequence

The Miocene represents a key moment in the South American evolution, since meaningful geographic and climatic processes occurred, promoting the development of several biologic changes. The isolation of South America together with major global and regional climatic changes resulted in an enormous variety of biomes and endemic diversity of flora and fauna, especially of mammals diversity. Most of the best-known continental vertebrate fossil-bearing deposits correspond to the early and late Miocene, existing a deficient knowledge for the middle Miocene, which is poorly understood at high latitudes. This work examines four new middle Miocene fossiliferous localities from a North Patagonian foreland succession, through a multidisciplinary approach that combines stratigraphic and preliminary paleontological analyses within a previously defined high-resolution temporal scheme. Two localities are referred to the lower section of Collón Cura Formation, and were constrained to a range of 14.6–12.75 Ma, whereas the other two localities correspond to the upper section of Collón Cura Formation and were constrained to 12.75–12.05 Ma. A large variety of fossil vertebrates were recognized in the lower section, belonging to Teleostei, Testudinidae, Teiidae, Anura and Mammalia; whereas Teleostei, Testudinidae and Mammalia vertebrates were documented in the upper section. Our results indicate a Colloncuran and younger (e.g., Mayoan) South American Mammals Ages (SALMAs) for the lower and upper sections of Collón Cura Formation, respectively. However, data from this work support the idea of a continuum on the SALMAs sequence for the middle Miocene where overlap, at least partially, both in absolute dates and in the faunal assemblages.

Diversification of Neotropical Freshwater Fishes

Neotropical freshwater fishes (NFFs) constitute the most diverse continental vertebrate fauna on Earth, with more than 6,200 named species compressed into an aquatic footprint <0.5% of the total regional land-surface area and representing the greatest phenotypic disparity and functional diversity of any continental ichthyofauna. Data from the fossil record and time-calibrated molecular phylogenies indicate that most higher taxa (e.g., genera, families) diversified relatively continuously through the Cenozoic, across broad geographic ranges of the South American platform. Biodiversity data for most NFF clades support a model of continental radiation rather than adaptive radiation, in which speciation occurs mainly in allopatry, and speciation and adaptation are largely decoupled. These radiations occurred under the perennial influence of river capture and sea-level oscillations, which episodically fragmented and merged portions of adjacent river networks. The future of the NFF fauna into the Anthropocene is uncertain, facing numerous threats at local, regional, and continental scales.

Gerinces fosszíliák és kutatásuk a Kárpát-medencében

The richest vertebrate sites in the Carpathian Basin are mainly Neogene and Pleistocene, but there are also some Mesozoic localities that have been researched for decades and are of great international interest. The highly sporadic Paleozoic finds are mostly based on microfossils (conodonts) and some Carboniferous-Perm footprints, the former being biostratigraphically and the latter paleobiogeographically important. In addition to some significant scattered finds (Placochelys placodonta) from the Triassic period, old and new localities in Bihar and Villany provided diverse, predominantly marine vertebrate faunas that significantly added to our knowledge on shelf faunas of the southern Eurasian margin. Our Jurassic vertebrate record is composed of mainly isolated finds (e.g. the Magyarosuchus marine crocodile) or tracksites (Komlosaurus). The oldest fauna of the Cretaceous period is the archosaurian assemblage trapped in the Berriasian aged bauxite of Bihar, followed in time by recently discovered fish and reptile bones and teeth from the Albian Alsopere Bauxite. The Santonian aged Iharkut and Ajka vertebrate sites, discovered 20 years ago, provided a unique and diverse assemblage that fills a significant gap in the Late Cretaceous European record. The Maastrichtian Transylvanian localities, discovered 125 years ago, provided a highly unique island fauna including huge pterosaurs, dwarf sauropods and dome-headed multituberculate mammals. These Late Cretaceous assemblages are now among the dominant continental vertebrate records worldwide, providing a great insight into the insular faunal evolution of the European archipelago. From the Hungarian Paleogene mainly sporadic fossil sites with aquatic vertebrates were discovered and only few of them yielded richer, terrestrial faunas (e.g. Mariahalom, Bodajk). The 17-million-year-old Ipolytarnoc footprints, conserved by a volcanic eruption, are the best known of the Lower Miocene fossils. The famous giant petrified pine trunk and a rich shark tooth assemblage have also been preserved in this site. Many remains of Badenian, Sarmatian and later (Pannonian) sea cows, seals and cetaceans were collected from the Mecsek sand layers (eg. Danitzpuszta sand mine). Several significant sites from the terrestrial Middle Miocene have been excavated in the last three decades (Samsonhaza, Matraszőlős, Hasznos, Tasad/Tasad), their small mammal faunas were preserved by swamps and lacustrine accumulations. They are indicators of a warm and humid subtropical climate. The fossil ape Rudapithecus hungaricus, which is the best known palaeontological finding of Hungary, is an element of the rich late Miocene (10 million years old) subtropical ecosystem of Rudabanya. A similar fossil community was discovered in the covering layer of a gypsum mine in Alsotelekes. Gyepufuzes (Kohfidisch), Gotzendorf, Sumeg, Csakvar, Berbaltavar, Tardosbanya, Polgardi and other rich sites reflect on the environmental transformation during the Pannonian Age when the rich, subtropical forests disappeared and were replaced by wooded and then grassy savannas and finally sporadic desert areas. The alginate layers of Pula locality were deposited in a Pliocene volcanic crater lake. They yielded many, well-preserved leaf and arthropod fossils, fish, and mammalian remains. The findings from Ajnacskő(Hajnacka) were preserved by a volcanic eruption, while the fauna of Ivanhaza was discovered in the sediments of karst fissures. The karst fillings of Csarnota, Beremend and Ostramos show the faunal changes of the end of Pliocene and the beginning of Lower Pleistocene. Exceptionally rich Quaternary assemblages were yielded by Gombaszog (Gombasek) in the Hungarian Highlands and from Betfia in Transylvania. More than 100 localities were described from the Pleistocene of Hungary and at least 150 different faunas were found in them. Most of them are from fillings of karst cavities, but there are also fluviatile and aeolian sediments. Many findings of ancient humans have also been found in several localities (e.g. Vertesszőlős: Homo hedelbergensis, Subalyuk: Homo sapiens neanderthalensis, Istalloskő: Homo sapiens sapiens). Detailed multidisciplinary investigations have been carried out in some of these faunas (e.g. Somssich Hill, Suttő, Tokod, Vaskapu Cave) by research groups of different specialists recently. Macro- and microfaunas of these sites appropriately reflect on Quaternary climatic changes.

Anatomy, Relationships, and Paleobiology of Cambaytherium (Mammalia, Perissodactylamorpha, Anthracobunia) from the lower Eocene of western India

ABSTRACT The anatomy of Cambaytherium, a primitive, perissodactyl-like mammal from the lower Eocene Cambay Shale Formation of Gujarat, India, is described in detail on the basis of more than 350 specimens that represent almost the entire dentition and the skeleton. Cambaytherium combines plesiomorphic traits typical of archaic ungulates such as phenacodontids with derived traits characteristic of early perissodactyls. Cambaytherium was a subcursorial animal better adapted for running than phenacodontids but less specialized than early perissodactyls. The cheek teeth are bunodont with large upper molar conules, not lophodont as in early perissodactyls; like perissodactyls, however, the lower molars have twinned metaconids and m3 has an extended hypoconulid lobe. A steep wear gradient with heavy wear in the middle of the tooth row suggests an abrasive herbivorous diet. Three species of Cambaytherium are recognized: C. thewissi (∼23 kg), C. gracilis (∼10 kg), and C. marinus (∼99 kg). Body masses were estimated from tooth size and long bone dimensions. Biostratigraphic and isotopic evidence indicates an age of ca. 54.5 Ma for the Cambay Shale vertebrate fauna, the oldest Cenozoic continental vertebrate assemblage from India, near or prior to the initial collision with Asia. Cambaytheriidae (also including Nakusia and Perissobune) and Anthracobunidae are sister taxa, constituting the clade Anthracobunia, which is sister to Perissodactyla. We unite them in a new higher taxon, Perissodactylamorpha. The antiquity and occurrence of Cambaytherium—the most primitive known perissodactylamorph—in India near or before its collision with Asia suggest that Perissodactyla evolved during the Paleocene on the Indian Plate or in peripheral areas of southern or southwestern Asia.

New data on the microvertebrate fauna from the Upper Jurassic or lowest Cretaceous of Ksar Metlili (Anoual Syncline, eastern Morocco)

AbstractThe Middle Jurassic – Early Cretaceous period witnessed the emergence of some major representatives of modern continental vertebrate groups (stem lissamphibians, squamates, therian mammals and birds) and angiosperms, at a time when fragmentation of Pangaea was underway. The successive Moroccan microvertebrate faunas of Ksar Metlili (?Berriasian) and Guelb el Ahmar (Bathonian) from the Anoual Syncline significantly improve our poor knowledge of Gondwanan and especially African palaeobiodiversity at this time. They are among the richest known from the Mesozoic of Gondwana, and are well placed in northwestern Africa to record faunal interchanges with Laurasia. Here we focus on the Ksar Metlili fauna, first documented in the 1980s and most recently resampled in 2010, which produced 24 541 microremains representing 47 species of 8 main groups (Chondrichthyes, Actinopterygii, Sarcopterygii, Lissamphibia, Lepidosauromorpha, Testudinata, Archosauromorpha and Synapsida). It includes remarkable taxa: the oldest stem boreosphenidan mammals from Gondwana, probably some of the last non-mammaliaform cynodonts, a basal ornithischian, possibly freshwater teleosaurid crocodylomorphs, and some of the rare occurrences of choristoderes and albanerpetontids in Gondwana. Comparison of the Ksar Metlili fauna with that of Guimarota (Kimmeridgian, Portugal) further provides evidence of numerous shared taxa of Laurasian affinities, in contrast to the occurrence of few taxa with Gondwanan affinities. This suggests complex palaeobiogeographical relationships – implying both vicariance and dispersal events – of North Africa within Gondwana at the Jurassic–Cretaceous transition. Finally, the faunal similarities with the Guelb el Ahmar fauna question the Cretaceous age of the Ksar Metlili fauna, suggesting an alternative possible Late Jurassic age.

Global biogeographical regions of freshwater fish species

AbstractAimTo define the major biogeographical regions and transition zones for freshwater fish species.TaxonStrictly freshwater species of actinopterygian fish (i.e. excluding marine and amphidromous fish families).MethodsWe based our bioregionalization on a global database of freshwater fish species occurrences in drainage basins, which, after filtering, includes 11,295 species in 2,581 basins. On the basis of this dataset, we generated a bipartite (basin‐species) network upon which we applied a hierarchical clustering algorithm (the Map Equation) to detect regions. We tested the robustness of regions with a sensitivity analysis. We identified transition zones between major regions with the participation coefficient, indicating the degree to which a basin has species from multiple regions.ResultsOur bioregionalization scheme showed two major supercontinental regions (Old World and New World, 50% species of the world and 99.96% endemics each). Nested within these two supercontinental regions lie six major regions (Nearctic, Neotropical, Palearctic, Ethiopian, Sino‐Oriental and Australian) with extremely high degrees of endemism (above 96% except for the Palearctic). Transition zones between regions were of limited extent compared to other groups of organisms. We identified numerous subregions with high diversity and endemism in tropical areas (e.g. Neotropical), and a few large subregions with low diversity and endemism at high latitudes (e.g. Palearctic).Main conclusionsOur results suggest that regions of freshwater fish species were shaped by events of vicariance and geodispersal which were similar to other groups, but with freshwater‐specific processes of isolation that led to extremely high degrees of endemism (far exceeding endemism rates of other continental vertebrates), specific boundary locations and limited extents of transition zones. The identified bioregions and transition zones of freshwater fish species reflect the strong isolation of freshwater fish faunas for the past 10–20 million years. The extremely high endemism and diversity of freshwater fish fauna raises many questions about the biogeographical consequences of current introductions and extinctions.

A new rebbachisaurid (Sauropoda: Diplodocoidea) from the middle Cretaceous of northern Brazil

A new genus and species of Rebbachisauridae sauropod from the Cenomanian of the São Luís Basin, Alcântara Formation, Itapeuasaurus cajapioensis gen. et sp. nov., is described, the first from this temporal interval in northern Brazil. It is characterized by the presence of large and deep fossae on ventro-lateral aspect of the dorsal neural arch split by laminae obliquely oriented; posterior centrodiapophyseal lamina forked ventrally forming the dorsal edge of the centrodiapophyseal fossa; dorsal and ventral components of anterior caudal transverse process thinner than the usual bony bar. This latter feature is associated with the presence of a prezygodiapophyseal centrodiapophyseal fossa accessory lamina. The phylogenetic analysis performed herein identifies the subclade Nigersaurinae as a South American – African/European clade, suggesting a vicariant event before Cenomanian times. In addition, continental vertebrate taxa recorded in the Alcântara Formation offer support to a minor evolutionary change after major vicariant event in Western Gondwana.

Vertebrate remains from the Turonian (Upper Cretaceous) Gosau Group of Gams, Austria

A new, systematically collected vertebrate assemblage from the upper Turonian Schönleiten Formation of Gams bei Hieflau, Austria (Northern Calcareous Alps) is described here. The material consists of teeth and bones of chondrichthyan (Selachimorpha indet., Ptychotrygon gueveli) and osteichthyan fishes (cf. Lepisosteus sp., Vidalamiinae indet., Pycnodontidae indet.), amphibians (cf. Thaumastosaurus sp.), lizards (’Lacertilia’ indet.), mosasauroids (Tethysaurinae indet.), Theriosuchus-like and other, peculiar crocodyliforms and theropod dinosaurs (cf. Paronychodon sp.). The faunal composition is most similar to the Santonian fauna of Iharkút, western Hungary, a phenomenon that can be explained by the spatial and temporal closeness of the two landmasses. The Gams assemblage is of great importance since continental vertebrates from the Cenomanian to Santonian interval of Europe are extremely scarce, and it provides a small but significant link between older and younger vertebrate faunas in the region.

The dirty dozen: taxonomical and taphonomical overview of a unique ankylosaurian (Dinosauria: Ornithischia) assemblage from the Santonian Iharkút locality, Hungary

Ankylosaurian fossils are usually standard elements of Cretaceous continental vertebrate localities; however, bone-yielding horizons including more than one individual are extremely rare. Here, we present a unique assemblage of 12 partial, articulated or associated ankylosaurian skeletons and thousands of isolated bones and teeth discovered from the Santonian Iharkut vertebrate locality, western Hungary. Collected from an area of 600 m2 and from a single bone bed, this material is one of the richest ankylosaurian accumulation worldwide. The 12 skeletons are not monospecific but mostly based on the pelvic armour composition: six of them are from Hungarosaurus, two are referred to Struthiosaurus and four can be assigned to Nodosauridae indet. Sedimentological and taphonomical examinations revealed a single mass mortality event as the cause of the death and accumulation of these quadruped animals that are described here. The ankylosaur assemblage from Iharkut suggests at least a temporarily gregarious behaviour of these animals and also shows that Hungarosaurus and Struthiosaurus might live in the same moist habitat or at least preferred relatively close environments.

U-Pb detrital zircon constraints on the depositional age and provenance of the dinosaur-bearing Upper Cretaceous Wadi Milk formation of Sudan

Cretaceous continental deposits in Sudan have long been recognized as important archives of continental vertebrate fossils in central Africa. A number of different sedimentary units including the Wadi Milk, Shendi and Kababish formations from northern and central Sudan are known to yield dinosaur and other vertebrate fossils. The ages of these deposits are poorly constrained, and traditionally assumed to be of Albian to Santonian age based on biostratigraphic evidence. However, recent palynological analyses suggest a Campanian–Maastrichtian age for the Shendi Formation. Not only are the ages of these units poorly resolved; but stratigraphic correlations within and between them and similar aged units in central Africa, remains tenuous. To address these issues a detailed sedimentary fingerprinting and provenance analysis was conducted on the putatively correlative Shendi and Wadi Milk formations using sandstone petrography and a multifaceted detrital zircon investigation combining U-Pb geochronology, Lu-Hf isotope analysis and trace element geochemistry. The objective was to provide constraints on the age of deposition, sediment sources and paleofluvial drainage patterns. Based on laser ablation ICP-MS U-Pb detrital zircon geochronology of 18 sandstone samples (>1400 detrital zircons), we identified a population of six Late Cretaceous zircons from the Wadi Milk Formation yielding a maximum depositional age of 79.2 ± 2.4 Ma (MSWD = 0.65, probability 0.62). Specifically, these data restrict the depositional age to Campanian or younger for the Wadi Milk Formation, which significantly refines our understanding of the age of this unit and its fauna. The Lu-Hf-isotope and trace element analyses of the remainder of the dated zircons show a provenance dominated by Neoproterozoic crustal sources and minor Paleoproterozoic and Archean sources for both units, which we interpret as being sourced from the Arabian-Nubian Shield to the south and southeast of the study area. These findings, coupled with the recently updated biostratigraphic age of the Shendi Formation, confirm that both units are correlative to one another and were probably deposited synchronously by north-north westerly flowing fluvial system draining into the Tethys Sea during the Late Cretaceous.

Chronostratigraphy and new vertebrate sites from the upper Maastrichtian of Huesca (Spain), and their relation with the K/Pg boundary

The transitional-continental facies of the Tremp Formation within the South-Pyrenean Central Unit (Spain) contain one of the best continental vertebrate records of the Upper Cretaceous in Europe. This Pyrenean area is therefore an exceptional place to study the extinction of continental vertebrates across the Cretaceous/Paleogene (K/Pg) boundary, being one of the few places in Europe that has a relatively continuous record ranging from the upper Campanian to lower Eocene. The Serraduy area, located on the northwest flank of the Tremp syncline, has seen the discovery of abundant vertebrate remains in recent years, highlights being the presence of hadrosaurid dinosaurs and eusuchian crocodylomorphs. Nevertheless, although these deposits have been provisionally assigned a Maastrichtian age, they have not previously been dated with absolute or relative methods. This paper presents a detailed stratigraphic, magnetostratigraphic and biostratigraphic study for the first time in this area, making it possible to assign most vertebrate sites from the Serraduy area a late Maastrichtian age, specifically within polarity chron C29r. These results confirm that the vertebrate sites from Serraduy are among the most modern of the Upper Cretaceous in Europe, being very close to the K/Pg boundary.

New Egyptian sauropod reveals Late Cretaceous dinosaur dispersal between Europe and Africa.

Prominent hypotheses advanced over the past two decades have sought to characterize the Late Cretaceous continental vertebrate palaeobiogeography of Gondwanan landmasses, but have proved difficult to test because terrestrial vertebrates from the final ~30 million years of the Mesozoic are extremely rare and fragmentary on continental Africa (including the then-conjoined Arabian Peninsula but excluding the island of Madagascar). Here we describe a new titanosaurian sauropod dinosaur, Mansourasaurus shahinae gen. et sp. nov., from the Upper Cretaceous (Campanian) Quseir Formation of the Dakhla Oasis of the Egyptian Western Desert. Represented by an associated partial skeleton that includes cranial elements, Mansourasaurus is the most completely preserved land-living vertebrate from the post-Cenomanian Cretaceous (~94-66 million years ago) of the African continent. Phylogenetic analyses demonstrate that Mansourasaurus is nested within a clade of penecontemporaneous titanosaurians from southern Europe and eastern Asia, thereby providing the first unambiguous evidence for a post-Cenomanian Cretaceous continental vertebrate clade that inhabited both Africa and Europe. The close relationship of Mansourasaurus to coeval Eurasian titanosaurians indicates that terrestrial vertebrate dispersal occurred between Eurasia and northern Africa after the tectonic separation of the latter from South America ~100 million years ago. These findings counter hypotheses that dinosaur faunas of the African mainland were completely isolated during the post-Cenomanian Cretaceous.