The Late Cretaceous (Santonian) fish fauna of the Iharkút vertebrate site (Bakony Mountains, Hungary) is described here. The ichthyofauna includes the lepisosteid Atractosteus sp., the pycnodontid cf. Coelodus sp., Vidalamiinae indet., a non-vidalamiin Amiidae indet., Elopiformes indet., two indeterminate ellimmichthyiforms, cf. Salmoniformes indet., Acanthomorpha indet., at least one indeterminate teleostean, and numerous indeterminate actinopterygians (represented by teeth). Among these taxa, the Iharkút remains of Vidalamiinae and the suggested indeterminate Salmoniformes represent their first occurrence in the Late Cretaceous of Europe. The unidentifiable specimens may suggest the presence of further fish taxa. The gar remains described here further support the Atractosteus sp. affinity of the Iharkút form. Most of the Iharkút fishes are carnivorous, but durophagous taxa are also represented. Although chondrichthyan remains have not been identified in the Iharkút vertebrate material up to now, the ecological distribution of some local fish taxa presumes the possible vicinity of a marine–deltaic environment. Several Iharkút fish taxa are known from North American localities as well, suggesting that the Late Cretaceous European continental fish might have been more diverse and similar to that of North America than previously thought. The necessity of more intensive screen-washing at other European Late Cretaceous vertebrate sites is also emphasized.

Abstract

In June 2017 a new sauropod trackway locality was discovered in the central part of the Adriatic–Dinaric Carbonate Platform (ADCP), on the island of Hvar (Croatia). The track site is situated on the northern shore of the western edge (Pelegrin) of the island in the upper Turonian – lower Coniacian limestone series. The track site contains altogether 13 footprints arranged in four possible trackways. The largest footprints have a diameter up to 80 cm. In some places the limestone surface is strongly karstified and the tracks are partly eroded, which has certainly modified the original shape and size of the footprints. Microfossil assemblage from the track-bearing beds suggest an early Coniacian age for the tracks. The new trackways on Hvar Island further strengthen the earlier hypothesis that sauropods were present in the western Tethyan archipelago during the late Cenomanian–late Campanian period. In addition, the new tracks, together with those from the Žukova Cove of Hvar, represent two, possibly slightly different stratigraphic horizons close to the Turonian–Coniacian boundary, and suggest that the occurrence of sauropods on the ADCP and possibly also on other parts of the Apulian microplate was not accidental, but rather periodical and more frequent than previously thought.

As a result of several years of screen-washing activity, a remarkable assemblage of eggshell fragments has been recovered from the Late Cretaceous vertebrate locality of Iharkút, Hungary. Detailed investigation of the assemblage by multiple visualization techniques (scanning electron microscopy, polarizing light microscopy, X-ray micro-computed tomography), quantitative morphometric analyses, and micro X-ray fluorescence spectrometry revealed a diverse composition of five different eggshell morphotypes (MT I–MT V) and three subcategories within the second morphotype (MT II/a, b, c), with MT I being by far the most abundant (83%) in the assemblage. MT I, MT III, and MT V represent theropod dinosaurian eggshells, whereas MT II and MT IV show characteristics of crocodilian and squamate eggshells, respectively. Hence, despite their fragmentary nature, these eggshells represent the first clear evidence that various sauropsid taxa had nesting sites near the ancient fluvial system of Iharkút. Besides the implied taxonomic diversity, two unique features add to the significance of this eggshell assemblage. First, it contains the thinnest rigid crocodilian (MT II/c) and squamate (MT IV) eggshells ever reported. Moreover, one of the identified theropod morphotypes, MT I, is also among the thinnest fossil dinosaurian eggshells, the thinness of which is only rivalled by the eggshells of the smallest Mesozoic avian eggs known to date. Second, the Iharkút eggshell assemblage consists exclusively of thin eggshells (≤300 µm), a condition unknown from any other fossil eggshell assemblages described to date. Combined with the knowledge acquired from skeletal remains, these peculiarities give additional insights into the paleoecology of the terrestrial sauropsid fauna once inhabiting the ancient island of Iharkút. Finally, the presence of well-preserved eggshells recovered from two different sites representing different depositional environments provides further evidence for previous taphonomic and sedimentological conclusions, and also expands our knowledge of the special conditions that allowed the preservation of these delicate eggshell fragments.

Abstract

Remains of Triassic vertebrates discovered in the Villány Hills (SW Hungary) are described here. After the well-documented Late Cretaceous Iharkút locality, this material represents the second systematically collected assemblage of Mesozoic vertebrates from Hungary. Fossils were collected from both the classical abandoned road-cut at Templom Hill (Templom-hegy) and a newly discovered site at a construction zone located 200 meters west of the road-cut. Macrofossils of the construction site are mainly isolated bones and teeth of nothosaurs from the Templomhegy Dolomite, including a fragmentary mandible referred to as Nothosaurus sp. and placodont teeth tentatively assigned here to cf. Cyamodus sp. Affinities of these fossils suggest a Middle Triassic (Ladinian) age of these shallow marine deposits.

New palynological data prove for the first time a Late Triassic (Carnian) age of the lower part of the Mészhegy Sandstone Formation. Vertebrate remains discovered in this formation clearly represent a typical Late Triassic shallow-marine fauna including both chondrichthyan (Lissodus, Palaeobates, Hybodus) and osteichthyan (cf. Saurichthys, ?Sphaerodus sp.) fish fossils. The presence of reworked nothosaur and placodont tooth fragments as well as of possible archosauriform teeth, suggest an increase of terrestrial influence and the erosion of underlying Triassic deposits during the Late Triassic.

A belemnite rostrum collected from the lowermost beds of the Somssichhegy Limestone Formation proves that this Lower Jurassic (Pliensbachian) layer was deposited in a marine environment. Most of the vertebrate remains (nothosaurs, placodonts, hybodont shark teeth, perhaps Palaeobates, Lissodus) recovered from these beds are also reworked Triassic elements strongly supporting an erosive, nearshore depositional environment.