The Carboniferous lungfish genus Sagenodus is reviewed from all available British specimens and described in detail for the first time. We identify two species exclusive to the UK: Sagenodusinaequalis, the type species, deriving from the late Carboniferous (=Pennsylvanian); and Sagenodus quinquecostatus derived from the early Carboniferous (=Mississippian). The genus is probably the most widespread of the known Carboniferous lungfish genera, but the British species have not been formally described since their discovery in the mid–late 19th Century. This work will provide data to help resolve existing questions about the position of Sagenodus in the phylogeny of Palaeozoic lungfishes, and provide a template for the recognition of isolated elements in museum collections and the finds from recent and future field work. The early Carboniferous species, S. quinquecostatus, shows a so far unique functional mechanism in which the lower tooth plates appear to rotate relative to the upper plates during jaw closure, implying a kinetic function at the symphysis or jaw joint.

Historical strandings and sightings (1989–2016) of Tursiops truncatus at 25oS in the south-western Atlantic Ocean (Paraná, Brazil) were assessed to (1) investigate temporal fluctuations; and (2) quantify biological, ecological and health parameters of regional populations. In total, 57 T. truncatus carcasses in mostly advanced stages of decomposition (~80% of all specimens) were recorded. Standardized temporal strandings (per observational effort) varied considerably and with no clear annual relationship beyond a peak in 2007, but there were consistently more strandings in winter/spring (74%) than summer/autumn (26%). While there was uncertainty over age estimation (i.e. not available for the population), individuals classified as juveniles/subadults were more frequent (80%) than calves (14%) and adults (6%). Of 28 carcasses assessed, 27 showed a positive linear relationship between TL and condyle-basal length, while one specimen had a clear southern skull morphotype. Suggestive lesions of Crassicauda sp. were recorded in 77% of assessed skulls and four types of tooth pathologies were observed. Nine individuals were more closely investigated for gross and histopathological alterations and had clear evidence of fishery interactions and various health issues associated with disease and oedema accompanied by alveolar fibrosis. While the regional frequency of T. truncatus strandings was lower than other more vulnerable cetaceans, the absolute numbers (e.g. 15 individuals in 2016) and some uncertainty concerning regional taxonomy are noteworthy, and justify ongoing spatio-temporal monitoring. Further, given the evidence of disease in some specimens, future work should not only encompass rigorous taxonomic assessments, but also health to comprehensively evaluate regional stocks. Small cetacean species are sentinels and their condition could inform ongoing environmental assessments.

Lizards, snakes and amphisbaenians together constitute the Squamata, the largest and most diverse group of living reptiles. Despite their current success, the early squamate fossil record is extremely patchy. The last major survey of squamate palaeontology and evolution was published 20 years ago. Since then, there have been major changes in systematic theory and methodology, as well as a steady trickle of new fossil finds. This review examines our current understanding of the first 150 million years of squamate evolution in the light of the new data and changing ideas. Contrary to previous reports, no squamate fossils are currently documented before the Jurassic. Nonetheless, indirect evidence predicts that squamates had evolved by at least the middle Triassic, and had diversified into existing major lineages before the end of this period. There is thus a major gap in the squamate record at a time when key morphological features were evolving. With the exception of fragmentary remains from Africa and India, Jurassic squamates are known only from localities in northern continents (Laurasia). The situation improves in the Early Cretaceous, but the southern (Gondwanan) record remains extremely poor. This constrains palaeobiogeographic discussion and makes it difficult to predict centres of origin for major squamate clades on the basis of fossil evidence alone. Preliminary mapping of morphological characters onto a consensus tree demonstrates stages in the sequence of acquisition for some characters of the skull and postcranial skeleton, but many crucial stages – most notably those relating to the acquisition of squamate skull kinesis – remain unclear.

Cranial variability was studied in 307 Eastern hedgehogs Erinaceus concolor Martin, 1838 from central and south-eastern Europe, the Near East, Middle East, and the Caucasus. The maxillary bone always contacted the nasal bone in European samples, forming a naso-maxillary suture which was mainly long (>2 mm). In contrast, the suture was usually short (<1–2 mm) in hedgehogs from the Near East and Middle East, and sometimes the maxillary failed to reach the nasal bone. In the latter case, the premaxillary formed a suture with the frontal bone (length = 2.5 mm in extreme cases). Two morphotypes could be distinguished on this basis: the roumanicus morphotype (with a long suture) and the concolor morphotype (with the naso-maxillary suture short or absent). Discriminant function analysis of nine geographic samples, and based on 14 linear log-transformed skull measurements, revealed two clusters: one included four European samples of the roumanicus morphotype and the other contained three Asiatic samples of the concolor morphotype. Specimens of the roumanicus morphotype from Asia were classified as having either the concolor or roumanicus morphotype; however, on average their skull morphology suggested closer affinities with the former.