DOI: 10.3897/vz.76.e180962

Authors: Nikoleta Dubjelová, Tereza Hadravová, Martin Ivanov, Ivan Horáček

Abstract: The European Pleistocene populations of the narrow-headed vole (Stenocranius gregalis), an index species of the Palearctic glacial communities, were recently found to differ from the extant Asian species by a deep genetic divergence and are to be considered a separate species, Stenocranius anglicus, which had to persist through the interglacial stages in local European refugia. Here, we analyze over 2000 first lower molars from 14 stratified localities in the Czech Republic and Slovakia, spanning the Middle Pleistocene to Holocene, employing geometric morphometrics, biometric measurements, and morphotype classifications to assess molar shape variation. Our results demonstrate persistent morphological variability, with particularly high morphotype diversity during MIS 5–3, followed by simplification and reduced variance in post–LGM populations. Morphological divergence was greater among geographic localities than stratigraphic stages, suggesting strong regional and ecological influences. Stratified sequences reveal diverse evolutionary trajectories from long-term morphological stability in refugia to gradual simplification preceding extinction in the early Holocene. These patterns align with broader Eurasian trends but also highlight regionally specific responses to climatic and ecological change accompanying the species’ extinction dynamics during the early to middle Holocene. The paper underscores the importance of integrating detailed morphometrics with stratigraphic and ecological evidence to shed light on these topics.

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DOI: 10.3897/vz.76.e182505

Authors: Gerald Mayr

Abstract: Abstract A diverse array of early Eocene zygodactyl birds has been assigned to the Psittacopasseres, the clade including parrots and passerines, but the exact affinities of the fossils are controversially resolved. Here, new analyses are performed based on a revised character matrix. Concerning critical taxa, the results of the primary analysis and that of the analyses constrained to a molecular backbone phylogeny show disparate tree topologies, and probably none correctly reflects the true interrelationships of the fossil taxa. The new taxon Psittacomimidae fam. nov. is introduced for a clade formed by the taxa Psittacomimus and Parapsittacopes, which were before assigned to the Psittacopedidae. The Psittacomimidae fam. nov. are likely to be the sister taxon of the Parapasseres, that is, the clade formed by the Zygodactylidae and Passeriformes, with the Morsoravidae branching next. A clade formed by all or most Halcyornithidae and the Messelasturidae is termed Messelasturiformes. A derived morphology of the proximal tarsometatarsus is reported, which may support a clade including the Vastanavidae and Messelasturiformes. However, although psittacopasserine affinities of the Vastanavidae conform to the overall osteology of these birds, the higher-level affinities of the Messelasturiformes are more elusive.

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DOI: 10.3897/vz.75.e146618

Authors: Sergio Sánchez-Fenollosa, Alberto Cobos

Abstract: Abstract Stegosauria is an iconic clade of thyreophoran dinosaurs mainly characterized by two parasagittal rows of osteoderms that extend from the neck to the end of the tail. The fossil record of stegosaurian cranial material is remarkably fragmentary and scarce. This study describes the most complete stegosaurian skull from Europe and proposes a new hypothesis for the phylogenetic relationships of stegosaurs. This new cranial material was recovered from beds of the Villar del Arzobispo Formation (Upper Jurassic, Teruel, Spain) and is confidently referred to Dacentrurus armatus. It provides valuable insights into the anatomy of this species and enhances the understanding of skull evolution in stegosaurs. Furthermore, the diagnosis of D. armatus is updated with the identification of a new autapomorphy. Stegosaurian phylogenetic nomenclature is also revised. Maximum Parsimony has been applied to analyse a new stegosaurian data matrix. Phylogenetic analyses suggest that Stegosauria is divided into two major clades: Huayangosauridae and Stegosauridae. These analyses support Isaberrysaura mollensis as a stegosaur and place it within Huayangosauridae, a clade that also includes several Jurassic stegosaurs from Asia. For the first time, Mongolostegus exspectabilis is included in a phylogenetic analysis, the results of which suggests that a lineage of huayangosaurids or early-diverging stegosaurids persisted in Asia until at least the late Early Cretaceous. The new tree topologies challenge the synonymization of the genera Stegosaurus and Wuerhosaurus. Moreover, it is concluded that a taxonomic re-evaluation of Early Cretaceous Chinese stegosaurs is necessary. Alcovasaurus longispinus and Kentrosaurus aethiopicus are recovered as dacentrurines.

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