Reassessment of the enigmatic Late Cretaceous theropod dinosaur, Bagaraatan ostromi

The Late Cretaceous Bagaraatan ostromi, described by Osmólska in 1996, is one of the most enigmatic theropod dinosaurs. The holotype possesses a peculiar combination of features, which Osmólska suggested were indicative of a primitive position among theropods that could not be resolved further. Other researchers have pointed to affinities with either derived bird-like coelurosaurs or tyrannosaurids. Here, we reanalyse all material collected by Osmólska, which reveals it to be a chimaera of multiple theropod taxa. The femur, tibiotarsus, one pedal phalanx, and most of the bones undescribed in Osmólska’s paper are identified as Caenagnathidae indet. The mandible, cervical vertebrae, pelvis, tail, and one pedal phalanx, which we consider the holotype of B. ostromi, show tyrannosaurid affinities, which are here supported by phylogenetic analyses. We find only two potentially unique diagnostic features of the Bagaraatan holotype: double surangular foramina and a horizontal ridge on the lateral surface of the postacetabular process of the ilium. Both, however, may be ontogenetically or intraspecifically variable, and thus we conclude that the holotype of B. ostromi represents an indeterminate tyrannosaurid. The small size of the holotype and its possession of many features known to characterize juvenile Tyrannosaurus rex indicate that the skeleton belongs to a juvenile, which is one of the smallest juvenile tyrannosaurids currently known

The oldest record of aquatic amniote congenital scoliosis

This research was supported by the National Science Center (Narodowe Centrum Nauki, www.ncn.gov.pl), Poland, project no. 2011/ 01/N/ST10/06989 granted to D. Surmik. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. There was no additional external funding received for this study.We report the first occurrence of congenital scoliosis in an early Permian aquatic parareptile, Stereosternum tumidum from Paraná state, Brazil. The spine malformation is caused by a congenital hemivertebra. These observations give insight into the biomechanical aspects of underwater locomotion in an axial skeleton-compromised aquatic amniote. This is the oldest record of a hemivertebra in an aquatic animal.National Science Center (Narodowe Centrum Nauki, www.ncn.gov.pl

Tuberculosis-like respiratory infection in 245-million-year-old marine reptile suggested by bone pathologies

An absence of ancient archaeological and palaeontological evidence of pneumonia contrasts with its recognition in the more recent archaeological record. We document an apparent infection-mediated periosteal reaction affecting the dorsal ribs in a Middle Triassic eosauropterygian historically referred to as ‘Proneusticosaurus’ silesiacus. Highresolution X-ray microtomography and histological studies of the pathologically altered ribs revealed the presence of a continuous solid periosteal reaction with multiple superficial blebs (protrusions) on the visceral surfaces of several ribs. Increased vascularization and uneven lines of arrested growth document that the pathology was the result of a multiseasonal disease. While visceral surface localization of this periosteal reaction represents the earliest identified evidence for pneumonia, the blebs may have an additional implication: they have only been previously recognized in humans with tuberculosis (TB). Along with this diagnosis is the presence of focal vertebral erosions, parsimoniously compared to vertebral manifestation of TB in humans

The oldest record of aquatic amniote congenital scoliosis

We report the first occurrence of congenital scoliosis in an early Permian aquatic parareptile, Stereosternum tumidum from Parana ́ state, Brazil. The spine malformation is caused by a congenital hemivertebra. These observations give insight into the biomechanical aspects of underwater locomotion in an axial skeleton-compromised aquatic amniote. This is the oldest record of a hemivertebra in an aquatic animal

Tuberculosis-like respiratory infection in 245-million-year-old marine reptile suggested by bone pathologies

An absence of ancient archaeological and palaeontological evidence of pneumonia contrasts with its recognition in the more recent archaeological record. We document an apparent infection-mediated periosteal reaction affecting the dorsal ribs in a Middle Triassic eosauropterygian historically referred to as ‘Proneusticosaurus’ silesiacus. High- resolution X-ray microtomography and histological studies of the pathologically altered ribs revealed the presence of a continuous solid periosteal reaction with multiple superficial blebs (protrusions) on the visceral surfaces of several ribs. Increased vascularization and uneven lines of arrested growth document that the pathology was the result of a multi- seasonal disease. While visceral surface localization of this periosteal reaction represents the earliest identified evidence for pneumonia, the blebs may have an additional implication: they have only been previously recognized in humans with tuberculosis (TB). Along with this diagnosis is the presence of focal vertebral erosions, parsimoniously compared to vertebral manifestation of TB in humans

Limb histology of the Triassic stem turtles Proterochersis porebensis Szczygielski & Sulej, 2016 and Proganochelys quenstedtii Baur, 1887 with insights into growth patterns of early turtles

Data on turtle limb bone histology and microstructure are spotty, especially for Mesozoic taxa, despite significant progress made in recent years. Here we provide first detailed information on the stylopodia of the Late Triassic stem turtles Proganochelys quenstedtii Baur, 1887 from Switzerland and Proterochersis porebensis Szczygielski & Sulej, 2016 from Poland. In both taxa we observed large, internal medullary regions filled with endosteal trabeculae and poorly to moderately vascularized parallel-fibered (grading locally to lamellar) periosteal cortices. Primary vasculature is predominantly longitudinal, in Proterochersis porebensis locally with radial inclination. In large specimens, secondary remodeling is significant in the deeper cortex, but it neither completely obliterates the primary tissue nor reaches the external surface of the bone in either taxon. Comparison of histological data, limb morphology, shell and limb lengths as well as proportions reveal differences in growth patterns between the taxa: Proganochelys quenstedtii seems to grow faster during early life stages than Proterochersis porebensis and attained distinctly larger body sizes earlier in ontogeny, even though the asymptotic body size is roughly the same for both species. Overall, the histological and microstructural characteristics of stylopodial bones of Triassic turtles more closely resemble those of more recent representatives of that group than earlier stem turtles

Shell variability in the stem turtles Proterochersis spp.

Background Turtle shells tend to exhibit frequent and substantial variability, both in bone and scute layout. Aside from secondary changes, caused by diseases, parasites, and trauma, this variability appears to be inherent and result from stochastic or externally induced flaws of developmental programs. It is, thus, expected to be present in fossil turtle species at least as prominently, as in modern populations. Descriptions of variability and ontogeny are, however, rare for fossil turtles, mainly due to rarity, incompleteness, damage, and post-mortem deformation of their remains. This paper is an attempt at description and interpretation of external shell variability in representatives of the oldest true turtles, Proterochersis robusta and Proterochersis porebensis (Proterochersidae, the sister group to all other known testudinatans) from the Late Triassic (Norian) of Germany and Poland. Methods All the available shell remains of Proterochersis robusta (13 specimens) and Proterochersis porebensis (275 specimens) were studied morphologically in order to identify any ontogenetic changes, intraspecific variability, sexual dimorphism, and shell abnormalities. To test the inferred sexual dimorphism, shape analyses were performed for two regions (gular and anal) of the plastron. Results Proterochersis spp. exhibits large shell variability, and at least some of the observed changes seem to be correlated with ontogeny (growth of gulars, extragulars, caudals, and marginals, disappearance of middorsal keel on the carapace). Several specimens show abnormal layout of scute sulci, several others unusual morphologies of vertebral scute areas, one has an additional pair of plastral scutes, and one extraordinarily pronounced, likely pathological, growth rings on the carapace. Both species are represented in a wide spectrum of sizes, from hatchlings to old, mature individuals. The largest fragmentary specimens of Proterochersis porebensis allow estimation of its maximal carapace length at approximately 80 cm, while Proterochersis robusta appears to have reached lower maximal sizes. Discussion This is the second contribution describing variability among numerous specimens of Triassic turtles, and the first to show evidence of unambiguous shell abnormalities. Presented data supplement the sparse knowledge of shell scute development in the earliest turtles and suggest that at least some aspects of the developmental programs governing scute development were already similar in the Late Triassic to these of modern forms

New tomographic contribution to characterizing mesosaurid congenital scoliosis

The presence of a pathology in the vertebral column of the early Permian mesosaurid specimen ZPAL R VII/1, being one of the oldest amniotic occurrences of congenital scoliosis caused by a hemivertebra, was recently recognized. Here we provide CT data to further characterize the phenomenon. The affected hemivertebra is wedged (incarcerated) between the preceding and succeeding vertebrae. The neural canal is misshapen but continuous and the number of dorsal ribs on each side of the specimen corresponds with the number of the vertebrae, documenting its congenital (homeobox-related) derivation

Dinosaur senescence: a hadrosauroid with age-related diseases brings a new perspective of “old” dinosaurs

Senile vertebrates are extremely rare in the fossil record, making their recognition difficult. Here we present the largest known representative of the Late Cretaceous hadrosauriform Gobihadros mongoliensis showing features of cessation of growth indicating attainment of the terminal size. Moreover, this is the first non-avian dinosaur with an age-related pathology recognized as primary calcium pyrophosphate deposition disease indicating its advanced age. Because senile dinosaurs are so rare and thus “senescence” in dinosaurs is unclear, we also propose a new unified definition of a senile dinosaur: an individual which achieved the terminal size as revealed by the presence of the external fundamental system and closed transcortical channels, has completely secondary remodeled weight-bearing bones and possesses non-traumatic, non-contagious bone pathologies correlated with advanced age

Goosefoot - a plant that likes drought. The goosefoot family pollen season in 2019 in Poland, Hungary and Slovakia

Almost all the species of the Chenopodiaceae family present in our flora flower from July–August to the autumn. Unfortunately, allergies do not take a vacation. Warm, dry July and August weather should limit pollen emissions. However, similarly to most plants in dry habitats, goosefoot are well adapted to such conditions and does not provide even a short reprieve to pollen allergic patients. However, goosefoot pollen does not have a very large allergenic significance; despite the long pollen season lasting about 3 months, pollen concentrations in the air are low and very rarely exceed the concentration of 30 grains/m3. This study compares Chenopodiaceae pollen seasons in Poland, Hungary and Slovakia in 2019. The investigations were carried out using the volumetric method (Hirst type pollen sampler). Seasonal pollen index was estimated as the sum of daily average pollen concentrations in the given season. The pollen season ranges from June to September, depending on the geographical latitude. In Hungary and Slovakia there are much longer pollen seasons than in Poland. Pollen of goosefoot family contains the panallergen profilins, which are responsible for cross-reactivity among pollen-sensitized patients. In 2019 the pollen season of goosefoot started first in Hungary, in Kaposvar on June 7th and in Slovakia, in Žilina, on June 8th; in Poland pollen season started much later, on June 14th in Szczecin and Opole. At the latest, a pollen season ended in Nitria (Slovakia) on October 16th; in Kecskemet (Hungary) on October 3rd. In Poland the season ended much earlier than in Hungary and Slovakia already on August 25th. The differences of pollen season durations are considerable, the number of days ranged from 72 to 128. The dynamics of the pollen seasons of goosefoot family show similarities within a given country and considerable differences between these countries. However, the differences of the highest airborne concentration between the countries are not considerable (25 pollen grains/m3 in Poland, 49 pollen grains/m3 in Hungary, and 30 pollen grains/m3 in Slovakia. The maximum values of seasonal pollen count in Polish cities occurred between July 26th and August 29th, in Hungarian cities between August 27th and 30th, and in Slovakian cities between August 7th and 28th. Pollen season was characterized by extremely different total annual pollen SPI, in Poland from 116 to 360; in Hungary and Slovakia within the limits 290 to 980. Droughts that occur more frequently during the summer facilitate the spread of species of the goosefoot family due to the possibility of these plants gaining new habitats