Radial porosity profiles are a powerful tool for tracing locomotor maturation in developing limb bones

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Sympatry of two ankylosaurs (Hungarosaurus and cf. Struthiosaurus) in the Santonian of Hungary

Abstract A complete and well-preserved right ankylosaurian humerus from the Upper Cretaceous (Santonian) Csehbánya Formation of Iharkút, western Hungary is described here. Based on its osteological features and 21.5 cm adult length, the new specimen is markedly different from the slender humerus of Hungarosaurus, the previously known ankylosaur from the locality, and more similar to that of Struthiosaurus. Thus, the new Hungarian specimen is tentatively assigned here to cf. Struthiosaurus thereby dating back the first occurrence of this genus to the Santonian. The new fossil demonstrates the sympatric co-existence of two different nodosaurid ankylosaurs (a smaller, robust form with 2–2.5 m total body length and a larger, cursorial form with 4–4.5 m body length) in the Iharkút fauna. This also suggests that the pattern of the European ankylosaur diversity was more complex than previously thought

Medullary bone-like tissue in the mandibular symphyses of a pterosaur suggests non-reproductive significance

Medullary bone is a special bone tissue forming on the endosteal surface of the medullary cavity in the bones of female birds prior to and during egg-laying to serve as a calcium reservoir for building the hard eggshell. It has also been identified in non-avian dinosaurs, where its presence is considered as a reliable indicator of a sexually mature female. Here, we reveal that multiple mandibular symphyses of the azhdarchid pterosaur Bakonydraco galaczi possess a special bone tissue that shows all microanatomical, histological, and developmental characteristics of medullary bone, despite its unusual location. Its frequent occurrence in the sample renders a pathologic origin unlikely. Our findings as well as the extremely thin-shelled eggs of pterosaurs suggest that this medullary bone-like tissue probably had a non-reproductive role in these animals. Although the non-reproductive significance and the anatomical location of this medullary bone-like tissue in Bakonydraco suggest independent evolutionary appearance from dinosaurian medullary bone, a common origin and later diverging function and physiological regulation is an equally viable phylogenetic hypothesis

Inferred bite marks on a Late Cretaceous (Santonian) bothremydid turtle and a hylaeochampsid crocodilian from Hungary

The Iharkút locality in the Bakony Mountains of western Hungary has provided a rich and diverse assemblage of Late Cretaceous vertebrates. Here we present two specimens of this assemblage, a plate fragment of the bothremydid turtle Foxemys trabanti, and a partial skull roof of the hylaeochampsid crocodilian, Iharkutosuchus makadii, that exhibit pathological traits, such as shallow and deep pits, bisected pits, and scores on their surface, and in the case of the skull roof, also a hole piercing through the entire bone thickness. Morphological and bone histological features of these pathological traits imply that they probably represent bite marks rather than deformations due to pre-mortem shell diseases, infections or post-mortem invertebrate bioerosion, and microbial activity. Morphological similarities with experimentally investigated crocodilian tooth marks suggest that both elements bear the bite marks of a crocodilian predator with typical conical teeth, possibly the Allodaposuchus-like crocodile, also known from the locality. The inferred tooth marks on the dorsal surface of the Iharkutosuchus skull roof indicate a rarely documented predator-prey interaction between two different crocodilian taxa rather than antagonistic behaviour over common resources. Nevertheless, more comparative studies are needed on different traumatic as well as non-traumatic bone pathologies that may eventuate in bite-mark-like abnormalities. © 2014