We describe new specimens of the basal ornithischian dinosaur Lesothosaurus diagnosticus Galton, 1978 collected from a bonebed in the Fouriesburg district of the Free State, South Africa. The material was collected from the upper Elliot Formation (Early Jurassic) and represents the remains of at least three individuals. These individuals are larger in body size than those already known in museum collections and offer additional information on cranial ontogeny in the taxon. Moreover, they are similar in size to the sympatric taxon Stormbergia dangershoeki. The discovery of three individuals at this locality might imply group-living behaviour in this early ornithischian.

Massospondylus carinatus Owen, 1854, from the earliest Jurassic upper Elliot Formation of South Africa, was one of the first dinosaurs to be described from Gondwana. It has been incorporated into numerous phylogenetic, palaeobiological and biostratigraphic analyses, is often viewed as an exemplar for understanding sauropodomorph anatomy and is a key taxon in studies of early dinosaur evolution. Since its initial description, numerous specimens have been referred to this species, ranging from isolated postcranial elements to complete skeletons with three-dimensional skulls. In addition,M. carinatus has been identified in areas outside of the main Karoo Basin. Surprisingly, however, there have been few attempts to define the taxon rigorously, so that the basis for many of these referrals is weak, undermining the utility of this abundant material. Here, we provide the first detailed postcranial description of the neotype specimen of M. carinatus, use it as a basis for diagnosing the species on the basis of cranial, axial and appendicular characters, demonstrate that it represents an adult individual on the basis of osteohistology, and discuss ways in which these data can assist in providing a better understanding of Karoo-aged African dinosaur faunas.

Massopondylus carinatus Owen, 1854 is a non-sauropodan sauropodomorph (‘prosauropod’) dinosaur whose remains are abundant in the Upper Karoo Supergroup sediments of southern Africa (e.g. Owen, 1854; Seeley, 1895; Cooper, 1981; Gow, 1990; Gow et al., 1990; Sues et al., 2004; Barrett and Yates, 2006; Reisz et al., 2005). It occurs at numerous localities in the Upper Elliot and Clarens formations of South Africa and Lesotho, as well as in the Forest Sandstone Formation of Zimbabwe (Haughton, 1924; Cooper, 1981; Kitching and Raath, 1984). Several almost complete skeletons are known, including skulls, and as a result Massospondylus has featured heavily in discussions of early dinosaur ecology, phylogeny and palaeobiology (e.g. Cooper, 1981; Barrett, 2000; Zelenitsky and Modesto, 2002; Reisz et al., 2005, 2012, Apaldetti et al., 2011, among many others). However, the original syntype series of Massospondylus carinatus was destroyed during World War II and shown to be taxonomically indeterminate, undermining the nomenclatural stability of this important taxon (Sues et al. 2004; Yates and Barrett, 2010). In order to rectify this problem, a complete skeleton representing an adult individual, BP/1/4934 (nicknamed ‘Big Momma’), was designated as the neotype (Yates and Barrett, 2010). BP/1/4934 was collected from the Upper Elliot Formation of Bormansdrift Farm, in the Clocholan District of the Free State, by Lucas Huma and James Kitching in 1980 (see Kitching and Raath, 1984, for locality details). This farm is also the type locality of the early turtle Australochelys (Gaffney and Kitching, 1994) and has yielded other Upper Elliot formation tetrapod material including the cynodont Pachygenelus and other sauropodomorph remains (Kitching and Raath, 1984). BP/1/4934 is the most complete specimen of a non-sauropodan sauropodomorph dinosaur known from the entire African continent and is therefore of major regional and international significance. In addition, since 1990 it has formed part of a permanent public exhibit showcasing African palaeontological discoveries in the J. W. Kitching Gallery of the Evolutionary Studies Institute (ESI) of the University of the Witwatersrand. During recent research work on BP/1/4934, as part of an on-going collaboration on early dinosaurs between the ESI and Natural History Museum, London (NHMUK), it was noted that its condition had deteriorated and that urgent remedial conservation work was required in order to preserve it for future generations. As a result, the specimen was temporarily removed from public display to facilitate this work, which is described in detail below (see also Graham, 2017). The primary purpose of the conservation project was to assess the condition of the specimen, undertake conservation in order to stabilise it and to manufacture ‘clam-shell’ type support mounts/jackets for each of the blocks to enable the specimen to be displayed in an articulated posture within a purpose-built display case. An important consideration was that the blocks should be readily accessible from both left and right sides to researchers whilst securing the fossil safely. Finally, this project also provided an opportunity to facilitate knowledge exchange between the conservation staff at the ESI and NHMUK, in order to share and extend technical expertise.

Knowledge of the early evolution of sea turtles (Chelonioidea) has been limited by conflicting phylogenetic hypotheses resulting from sparse taxon sampling and a superficial understanding of the morphology of key taxa. This limits our understanding of evolutionary adaptation to marine life in turtles, and in amniotes more broadly. One problematic group are the protostegids, Early–Late Cretaceous marine turtles that have been hypothesised to be either stem-cryptodires, stem-chelonioids, or crown-chelonioids. Different phylogenetic hypotheses for protostegids suggest different answers to key questions, including (1) the number of transitions to marine life in turtles, (2) the age of the chelonioid crown-group, and (3) patterns of skeletal evolution during marine adaptation. We present a detailed anatomical study of one of the earliest protostegids, Rhinochelys pulchriceps from the early Late Cretaceous of Europe, using high-resolution mCT. We synonymise all previously named European species and document the variation seen among them. A phylogeny of turtles with increased chelonioid taxon sampling and revised postcranial characters is provided, recovering protostegids as stem-chelonioids. Our results imply a mid Early Cretaceous origin of total-group chelonioids and an early Late Cretaceous age for crown-chelonioids, which may inform molecular clock analyses in future. Specialisations of the chelonioid flipper evolved in a stepwise-fashion, with innovations clustered into pulses at the origin of total-group chelonioids, and subsequently among dermochelyids, crown-cheloniids, and gigantic protostegids from the Late Cretaceous.

Our knowledge of Early Jurassic palaeobiodiversity in the upper Elliot Formation of South Africa has increased markedly in recent years with the discovery of new fossils, re-assessments of previously collected material and a better understanding of Stormberg Group stratigraphy. Here, Ngwevu intloko, a new genus of upper Elliot basal sauropodomorph is named on the basis of a complete skull and partial skeleton (BP/1/4779) previously assigned to Massospondylus carinatus. It can be distinguished from all other basal sauropodomorphs by a combination of 16 cranial and six postcranial characters. The new species is compared to a small ontogenetic series of M. carinatus as well as to a range of closely related taxa. Taphonomic deformation, sexual dimorphism and ontogeny are rejected as possible explanations for the morphological differences present between BP/1/4779 and other taxa. Osteohistological examination reveals that BP/1/4779 had nearly reached adult size at the time of its death at a minimum age of 10 years.

The rock dove (or common pigeon), Columba livia, is an important model organism in biological studies, including research focusing on head muscle anatomy, feeding kinematics, and cranial kinesis. However, no integrated computer-based biomechanical model of the pigeon head has yet been attempted. As an initial step towards achieving this goal, we present the first three-dimensional digital dissection of the pigeon head based on a contrast-enhanced computed tomographic dataset achieved using iodine potassium iodide as a staining agent. Our datasets enable us to visualize the skeletal and muscular anatomy, brain and cranial nerves, and major sense organs of the pigeon, including very small and fragile features, as well as maintaining the three-dimensional topology of anatomical structures. This work updates and supplements earlier anatomical work on this widely used laboratory organism. We resolve several key points of disagreement arising from previous descriptions of pigeon anatomy, including the precise arrangement of the external adductor muscles and their relationship to the posterior adductor. Examination of the eye muscles highlights differences between avian taxa and shows that pigeon eye muscles are more similar to those of a tinamou than they are to those of a house sparrow. Furthermore, we present our three-dimensional data as publicly accessible files for further research and education purposes. Digital dissection permits exceptional visualisation and will be a valuable resource for further investigations into the head anatomy of other bird species, as well as efforts to reconstruct soft tissues in fossil archosaurs.

The earliest definitive ornithischian dinosaurs are from the Early Jurassic and are rare components of early dinosaur faunas. The Lower Lufeng Formation (Hettangian–Sinemurian) of Yunnan Province, China, has yielded a diverse Early Jurassic terrestrial vertebrate fauna. This includes several incomplete specimens have been referred to Ornithischia, including the type specimen of the thyreophoran “Tatisaurus” and other generically indeterminate material. The highly fragmentary Lufeng ornithischian Bienosaurus lufengensis was described briefly in 2001 and identified as an ankylosaurian dinosaur. Recent studies have cast doubt on this hypothesis, however, and given that the referral of Bienosaurus to Ankylosauria would result in an extensive ghost-lineage extending between it and the first definitive eurypodans (ankylosaurs + stegosaurs) in the Middle Jurassic, the holotype specimen is re-examined and re-described. We identify Bienosaurus as a probable thyreophoran dinosaur, although the fragmentary nature of the material and the absence of autapomorphies means that the specimen should be regarded as a nomen dubium.

Background: Vertebrates possess a diverse range of integumentary epithelial appendages, including scales, feathers and hair. These structures share extensive early developmental homology, as they mostly originate from a conserved anatomical placode. In the context of avian epithelial appendages, feathers and scutate scales are known to develop from an anatomical placode. However, our understanding of avian reticulate (footpad) scale development remains unclear. Results: Here, we demonstrate that reticulate scales develop from restricted circular domains of thickened epithelium, with localised conserved gene expression in both the epithelium and underlying mesenchyme. These domains constitute either anatomical placodes, or circular initiatory fields (comparable to the avian feather tract). Subsequent patterning of reticulate scales is consistent with reaction–diffusion (RD) simulation, whereby this primary domain subdivides into smaller secondary units, which produce individual scales. In contrast, the footpad scales of a squamate model (the bearded dragon, Pogona vitticeps) develop synchronously across the ventral footpad surface. Conclusions: Widely conserved gene signalling underlies the initial development of avian reticulate scales. However, their subsequent patterning is distinct from the footpad scale patterning of a squamate model, and the feather and scutate scale patterning of birds. Therefore, we suggest reticulate scales are a comparatively derived epithelial appendage, patterned through a modified RD system.