Fragmentary Fossils Research Articles

Molar crown morphometrics in Paucituberculata (Mammalia: Marsupialia)

ABSTRACT The Paucituberculata are a group of marsupials endemic to South America, recorded from the Early Eocene to the present. In terms of taxonomy and qualitative morphology, paucituberculatans are a quite diverse and disparate group, especially considering their extinct representatives. This study aimed to investigate the variability in the quantitative morphology of paucituberculatans in the context of the largest morphometric study of the group performed to date. Due to the fragmentary fossil record, this work focused on lower dental morphology which allowed us to compare around 95% of paucituberculatan species through the measurement and analysis of almost 1500 specimens. Dental measurements of 27 variables were analysed by Principal Component Analysis and Partial Least Squares correlation as exploratory methods. As a result, it is shown that the continuous variability is expressed not only in size differences among species but also in morphological variability of individual teeth, and differences in size and proportions along the molar row. We conclude that paucituberculatans are a group of important morphological diversity regarding quantitative morphology. Many of the quantitative taxonomic features discussed in the literature were corroborated in this study. In addition, we discussed potential evolutionary and palaeoecological implications of this study, highlighting prospects for future studies.

New fossil genus and species of Yuripopovinidae (Insecta: Heteroptera, Coreoidea) from the Lower Cretaceous Jinju Formation, South Korea, with insights into the evolution of exaggerated antennae in the family

A new genus and species of Yuripopovinidae, Jinjupopovina eosahwae gen. et sp. nov. is described based on a piece of fragmentary fossil specimen from the lower Cretaceous Jinju Formation in Jinju City, South Korea. This species is the first record of Yuripopovinidae and the only heteropteran whose taxonomic status is reliably identified from the stratigraphic layer. Its antennal morphology provides a rare example of simultaneous enlargement in length and width among Heteroptera. Advantages and disadvantages of this antennal modification are discussed with references of other fossil and extant coreoids whose antennae are exaggerated. Our findings suggest that the antennae of Jinjupopovina facilitated visual signaling among infra-specific individuals or between reproductive partners. Evolutionary trends of the antennae in Yuripopovinidae are discussed with insights from Jinjupopovina.

Trophic interactions of sharks and crocodylians with a sea cow (Sirenia) from the Miocene of Venezuela

ABSTRACT Evidence of trophic interactions are not scarce in the fossil record, yet these are mostly represented by fragmentary fossils exhibiting marks of ambiguous significance. Differentiating between marks of active predation and scavenging events is therefore often challenging. Here, we report on a dugongine sea cow skeleton (partial skull and vertebrae) from the Lower to Middle Miocene Agua Clara Formation (Venezuela) with shark and crocodylian bite marks. The sirenian is identified as Culebratherium sp. and preserves crocodylian bite marks across the skeleton. The most conspicuous correspond to deep tooth impacts with dragging effect, concentrated in the rostrum of the specimen. We interpret these as the result of active predation because of the similarity with those produced when a crocodylian holds or rolls a prey. Additionally, shark bite marks can be observed throughout the skeleton, also evidenced by the finding of an isolated tiger shark (Galeocerdo aduncus) tooth associated with this skeleton. Because of the irregular distribution of the shark bite marks, these are interpreted as scavenging. Overall, these findings constitute one of the few records documenting multiple predators over a single prey, and as such provide a glimpse of the trophic networks during the Miocene in the region.

A Glimpse Into India’s Palaeoanthropological Past: Fossil Primates of the Pliocene and the Pleistocene

The Pliocene was a period of major faunal shift in India as older primate lineages slowly went extinct, leaving the niches vacant for cercopithecoids, specifically cercopithecids (Old World monkeys), to occupy. Among them, Presbytis sivalensis, Macaca palaeindica and Procynocephalus subhimalayanus are important, as they are potential kin to many of the South Asian and Southeast Asian monkeys living today. Further in the Pleistocene, as ecology shifted to a more grassland environment, primates such as Theropithecus delsoni and the first people of Homo sp. migrated into the subcontinent and occupied central India. All of these primate fossils are known only from a handful of fragmentary fossil remains. This article aims to discuss the discovery of fossils and the nature of these fossils from the Pliocene and the Pleistocene. Information regarding the phylogenetic affinities of these fossil primates is sporadic as well. There is a need to learn more about these primates by reanalysing existing discoveries and conducting further research into the lives of these primates of a bygone era. Such research, using modern tools and methods, will surely make significant contributions to palaeoanthropology.

New postcranial remains from the Lealt Shale Formation of the Isle of Skye, Scotland, showcase hidden pterosaur diversity in the Middle Jurassic

The Early to Middle Jurassic transition was significant in pterosaur evolution, during which these volant reptiles exploded in diversity alongside dinosaurs and other animals. It has long been thought, however, that pterosaurs did not develop large wingspans until after the Jurassic, a notion challenged by the recent discovery of Dearc sgiathanach in the Bathonian-aged Lealt Shale Formation of the Isle of Skye, Scotland, whose holotype specimen had an estimated wingspan greater than 2.5 m. We here report the discovery of a new pterosaur specimen from the Lealt Shale Formation, comprising a tibiotarsus, metatarsal, pedal phalanges and caudal vertebrae. The elongate tail vertebrae with ossified processes indicate that the specimen is a non-pterodactyloid pterosaur, albeit its fragmentary nature makes it difficult to determine whether it belongs to a new taxon. Its metatarsal and caudal vertebrae are considerably larger than corresponding bones in the Dearc holotype, indicating that it belonged to an even larger individual, thus demonstrating that pterosaurs with broad wingspans were not anomalous in the Middle Jurassic. The growing Middle Jurassic pterosaur record of Scotland and England, although mostly represented by isolated and fragmentary fossils, reveals a high diversity of clades, long obscured by the lack of well-preserved skeletons.

The shrews (Soricidae, Mammalia) of the Early and Middle Pleistocene of Gran Dolina (Atapuerca, Spain): reassessing their paleontological record in the Iberian Peninsula

Soricids are small mammals with a mainly invertebrate diet. They are generally termed insectivores and are part of the mammalian Order Eulipotyphla. Soricids of the Early-Middle Pleistocene postdating the Jaramillo subchron are poorly known in the Iberian Peninsula, except for Dolinasorex glyphodon, endemic to north Spain, and scattered records of Sorex minutus, Crocidura russula, Crocidura kornfeldi and indeterminate species of Crocidura, Sorex and Neomys. This is mainly due to the scarcity of sites and the fragmentary fossil remains. In contrast, the record of soricids in the rest of Europe during this period is wide: there are sites with up to ten different species in the same stratigraphic level. As Gran Dolina (Atapuerca, Spain) provides one of the best anthropological, archaeological and faunal records of the late-Early (post-Jaramillo) to early-Middle Pleistocene, and as this occurs in an excellent, well-studied stratigraphic sequence documenting terrestrial environments, we here undertake an exhaustive revision of 200 fragmentary mandibles of this group of small mammals. Nine soricid taxa were identified in this archaeo-paleontological site: Sorex minutus, Sorex ex gr. runtonensis-subaraneus, Sorex (Drepanosorex) ex gr. margaritodon-savini, Dolinasorex glyphodon, Asoriculus gibberodon, Neomys cf. newtoni, Neomys cf. fodiens, Neomyni cf. Macroneomys and Crocidura kornfeldi. This is the first record of Neomys cf. newtoni in the Iberian Peninsula, the second specimen of Neomyni cf. Macroneomys, and the youngest record of A. gibberodon worldwide. Some of these taxa exhibit particularities when compared to their counterparts in the rest of the continent, adding to the variability of the species. Relict populations of Asoriculus gibberodon endured in the Iberian Peninsula into post-Jaramillo times, even after they had already disappeared from the rest of Europe.

Osteological correlates of evolutionary transitions in cetacean feeding and related oropharyngeal functions

Teeth are often the first structures that anatomists and paleontologists examine to understand the ecology and morphology of feeding, both because teeth are highly specialized structures that provide precise information, and because they are among the best and most commonly preserved fossils. Unfortunately, many fragmentary fossil and recent specimens lack teeth, and some come from edentulous individuals and taxa, as in mysticete (baleen) whales. In our broad comparative review, we survey non-dental osteological features that, due to size, shape, arrangement, and surface features reflecting muscle attachments, provide useful clues to general or specific aspects of prey capture, intraoral transport, processing, or swallowing. We focus on hyoid, palatal, and pterygoid bones, mandibular symphyses and processes such as the coronoid, and the temporal fossa and zygomatic arch, as well as adjacent cranial bones relating to oral and pharyngeal anatomy. These bones relate to muscles of five general locations especially indicative of feeding: mandibular, hyoid, tongue, pharyngeal, and facial regions. Together these bones and muscles affect feeding and related activities including suckling and breathing. We discuss osteological correlates that provide special relevance to key transitions in cetacean evolutionary history, such as the shift from predominantly terrestrial to aquatic feeding, the shift from typical mammalian mastication to swallowing prey entirely or nearly whole, and the separation of respiratory and digestive passages. We also point to examples of modern specialists in these anatomical optima for different modes of prey capture, intraoral transport, processing, and swallowing. Although we focus on cetaceans, our approach is broadly relevant to all vertebrates, notably other marine tetrapods.

Making meaning from fragmentary fossils: Early Homo in the Early to early Middle Pleistocene

In celebration of the 50th anniversary of the Journal of Human Evolution, we re-evaluate the fossil record for early Homo (principally Homo erectus, Homo habilis, and Homo rudolfensis) from early diversification and dispersal in the Early Pleistocene to the ultimate demise of H. erectus in the early Middle Pleistocene. The mid-1990s marked an important historical turning point in our understanding of early Homo with the redating of key H. erectus localities, the discovery of small H. erectus in Asia, and the recovery of an even earlier presence of early Homo in Africa. As such, we compare our understanding of early Homo before and after this time and discuss how the order of fossil discovery and a focus on anchor specimens has shaped, and in many ways biased, our interpretations of early Homo species and the fossils allocated to them. Fragmentary specimens may counter conventional wisdom but are often overlooked in broad narratives. We recognize at least three different cranial and two or three pelvic morphotypes of early Homo. Just one postcranial morph aligns with any certainty to a cranial species, highlighting the importance of explicitly identifying how we link specimens together and to species; we offer two ways of visualizing these connections. Chronologically and morphologically H. erectus is a member of early Homo, not a temporally more recent species necessarily evolved from either H. habilis or H. rudolfensis. Nonetheless, an ancestral–descendant notion of their evolution influences expectations around the anatomy of missing elements, especially the foot. Weak support for long-held notions of postcranial modernity in H. erectus raises the possibility of alternative drivers of dispersal. New observations suggest that the dearth of faces in later H. erectus may mask taxonomic diversity in Asia and suggest various later mid-Pleistocene populations could derive from either Asia or Africa. Future advances will rest on the development of nuanced ways to affiliate fossils, greater transparency of implicit assumptions, and attention to detailed life history information for comparative collections; all critical pursuits for future research given the great potential they have to enrich our evolutionary reconstructions for the next fifty years and beyond.

An extinct owl (aves: strigidae) from the middle miocene of Patagonia

ABSTRACT Yarquen dolgopolae gen. et sp. nov. is described from fragmentary fossil bones (humerus and phalanges) found in the Middle Miocene Collón Curá Formation (Río Negro Province, Argentina). Fossil owls in Argentina are limited to occasional fragments as old as the Early Miocene to Late Pleistocene. Here, an extinct species is described. The humerus (MLP 92-V-10-86) is similar in size to that of the Short-eared Owl but differs mainly by the depth and arrangement of the fossa m brachialis, the fossa olecrani is shallow and rimless, the sulcus scapulotricipitalis is shallow, a pneumatic foramen located on a scar proximal to the condylus ventralis, the incisura intercondilaris is narrow and the condylus ventralis is rounded with a conspicuous groove running caudoventrally. The ungual phalanx of digit 1 shows a strongly curved corpus, lateral grooves on both sides, a processus extensorius dorsally directed, a flexor tubercle wide and robust and a crista slightly protruding that separates both cotylae. Aves recovered from the Collón Curá Formation correspond to diurnal hunters (Phorusrhacidae and Falconidae) to which is added this large owl that, like other Strigidae, presumably was nocturnal or crepuscular hunters.

A Jurassic Tibetan theropod tooth reveals dental convergency and its implication for identifying fragmentary fossils

<p><b>The Tibetan Plateau is among the least explored areas in terms of dinosaur paleontology in the world. Here, we report a dromaeosaurid-like tooth from the Middle Jurassic Dongdaqiao Formation at the eastern part of the plateau. The tooth exhibits dromaeosaurid dental features such as the absence of constriction at the cervix, a relatively small crown-to-base ratio, a strongly recurved apex, and it lacks large transverse and marginal undulations. Parsimonious phylogenetic analyses using both dentition-based and complete morphological matrices support a dromaeosaurid affinity for this tooth and place this Tibetan theropod as the sister taxon to</b> <i><b>Velociraptor</b></i><b>. However, Bayesian tip dating analyses based on the velociraptorine affinity of the Tibetan tooth place the majority of the diversifications of early-diverging Paravian within �C or earlier than �C the Middle Jurassic, which conflicts with the paravian fossil record. Furthermore, our discriminant analysis based on morphometric data places the Tibetan theropod within Metriacanthosauridae. These results may suggest that the broad resemblance between the Tibetan specimen and velociraptorine teeth is due to convergent evolution. Based on our results, other dromaeosaurid-like teeth reported from the Middle and Late Jurassic deposits throughout Eurasia could potentially be from non-dromaeosaurids. This study suggests the presence of an early diverged theropod lineage with a wide geographical distribution and potentially a dromaeosaurid-like dietary niche. This study also highlights the importance of using multiple lines of data to identify fragmentary fossils.</b></p>

A globally distributed durophagous marine reptile clade supports the rapid recovery of pelagic ecosystems after the Permo-Triassic mass extinction

Marine ecosystem recovery after the Permo-Triassic mass extinction (PTME) has been extensively studied in the shallow sea, but little is known about the nature of this process in pelagic ecosystems. Omphalosauridae, an enigmatic clade of open-water durophagous marine reptiles, potentially played an important role in the recovery, but their fragmentary fossils and uncertain phylogenetic position have hindered our understanding of their role in the process. Here we report the large basal ichthyosauriform Sclerocormus from the Early Triassic of China that clearly demonstrates an omphalosaurid affinity, allowing for the synonymy of the recently erected Nasorostra with Omphalosauridae. The skull also reveals the anatomy of the unique feeding apparatus of omphalosaurids, likely an adaptation for feeding on hard-shelled pelagic invertebrates, especially ammonoids. Morphofunctional analysis of jaws shows that omphalosaurids occupy the morphospace of marine turtles. Our discovery adds another piece of evidence for an explosive radiation of marine reptiles into the ocean in the Early Triassic and the rapid recovery of pelagic ecosystems after the PTME.

Towards a unifying systematic scheme of fossil and living billfishes (Teleostei, Istiophoridae)

Extant istiophorids are open ocean apex predators that are extensively studied due to their ecological importance and high values for fisheries. Nevertheless, little is known about their evolution because of a fragmentary fossil record and extremely difficult taxonomy of fossil species. Here, we present a new phylogenetic hypothesis covering fossil and living istiophorids. Our results demonstrate that istiophorid richness is larger than previously assumed, comprising eight genera with 20 species. The phylogenetic analysis shows that istiophorids are grouped into four clades: the Istiophorus clade, which includes the sailfish; the Machairostra clade, which comprises Makaira spp., including two new species from the late Miocene (†Makaira colonense sp. nov. and †Makaira fierstini sp. nov.); the Gracilorostra clade, which comprise all remaining istiophorids with exception of spearfishes and includes two new genera and one new species (†Morgula donosochagrense gen. et sp. nov. and †Spathochoira calvertense gen. et. comb. nov.); and the Tetrapturomorpha clade is composed of the spearfishes and the extinct †Prototetrapturus courcelli gen. et. comb. nov. The family Istiophoridae shows an evolutionary trend toward reduction of the premaxillary thickness and increasing the extension of narial cavities. This reduction is related to an increase of adipose tissues in the rostrum base probably driven by the presence of the oleofera gland, an organ involved in feeding, healing, endothermy and hydrophobic functions. Our phylogeny shows a direct relationship between the rostral and cranial shape explained by body size and feeding behaviour. The larger istiophorids have lateral apophysis and the larger spines of the vertebral column. The spearfishes represent the smaller species of the family, with the extant Tetrapturus spp. first appearing in the late Pliocene. The clade Tetrapturomorpha shows an extreme size reduction over time when compared with species of their sister clade Gracilorostra, demonstrating an evolutionary trend towards size reduction. http://zoobank.org/urn:lsid:zoobank.org:pub:D3D3B15B-36FA-42EB-98AD-FAF369D989EB

A new Cretaceous thyreophoran from Patagonia supports a South American lineage of armoured dinosaurs

The early evolution of thyreophoran dinosaurs is thought to have occurred primarily in northern continents since most evidence comes from the Lower and Middle Jurassic of Europe and North America. The diversification into stegosaurs and ankylosaurs is obscured by a patchy fossil record comprising only a handful of fragmentary fossils, most with uncertain phylogenetic affinities. Here we report the discovery of a new armoured dinosaur from the early Late Cretaceous of Argentina, recovered phylogenetically using various datasets either as a basal thyreophoran or a stem ankylosaur, closely related to Scelidosaurus. It bears unusual anatomical features showing that several traits traditionally associated with the heavy Cretaceous thyreophorans did not occur universally. Jakapil kaniukura gen. et sp. nov. is the first definitive thyreophoran species from the Argentinian Patagonia. Unlike most thyreophorans, it seems to show a bipedal stance, as in Scutellosaurus. Jakapil also shows that early thyreophorans had a much broader geographic distribution than previously thought. It is a member of an ancient basal thyreophoran lineage that survived until the Late Cretaceous in South America.

Diversity of schizomids (Arachnida: Schizomida) revealed by new fossil genera and species from mid-Cretaceous Burmese amber with implications for a Gondwanan origin of the Burma Terrane

Abstract Short-tailed whipscorpions are a small arachnid order with 379 described species from (sub)tropical regions of the world. The order has a fragmentary fossil record but has left a rich, albeit hitherto undocumented, fossil legacy in mid-Cretaceous amber from Myanmar, also called Burmese amber or Burmite. Here, we review a large series of schizomids from this type of amber and propose four new genera for seven new species. In addition, we include a short revision of all schizomid genera based on 14 morphological characters. Although none of the fossils can be assigned to Recent genera, they resemble the modern fauna in general morphology and highlight relative morphological stasis in this arachnid order. The fossils show a general trend towards eye reduction, but some of the specimens retain corneate eyes. Comparative data suggest affinities of the fossils with the Recent Old World fauna rather than American relatives. Furthermore, the fossils provide evidence for a Gondwanan origin of the Burma Terrane. Overall, the data suggest a high diversity at both species and genus levels for Burmese amber schizomids. We discuss potential reasons for this richness that will probably necessitate the description of additional genera and species in future studies.

A new gecko (Squamata, Gekkota) from the Eocene of Geiseltal (Germany) implies long‐term persistence of European Sphaerodactylidae

AbstractGekkota (geckos and pygopods) constitute a diverse and early diverging clade of squamates, but their highly fragmentary fossil record allows only limited insights into their evolutionary history. Even long‐known classic Palaeogene Lagerstätten, such as the Eocene Messel and Geiseltal, remained uninformative for gecko evolution. Here we describe an articulated near‐complete crown‐gekkotan skull from the Eocene of Geiseltal. The skull represents one of the most complete and oldest fossil geckos from the Cenozoic and warrants the naming of a new taxon, Geiseleptes delfinoi gen. et sp. nov. Parsimony analysis of an expanded morphological dataset that comprehensively samples fossil geckos recovers at least two lineages in the Palaeogene of Europe: Gekkonidae and Sphaerodactylidae. Further clades may have been present but require further support. The new species, together with several other European extinct taxa, belongs to the extant clade Sphaerodactylidae. Published molecular phylogenies imply a European dispersal from Africa for the clade, and G. delfinoi constrains the timing of this event to no later than the middle Eocene. Within Sphaerodactylidae, several Eocene, Oligocene and Miocene species form the stem‐lineage of the extant Mediterranean‐endemic Euleptes europaea of which G. delfinoi is the oldest representative. We here define the new clade Euleptinae for this group. Euleptine geckos had an unusually long evolutionary history in Cenozoic Europe and may represent one of the very few vertebrate clades with a persistent presence since the early Palaeogene, indicating extreme adaptability. As the oldest known crown‐sphaerodactylid, G. delfinoi represents an important fossil calibration for divergence dating analyses of geckos.

Discovery of plant cuticles in phyllite, late Pennsylvanian Southern Anthracite Field, eastern Pennsylvania, USA: a new research resource?

We report a small number of well preserved Late Pennsylvanian plant fossils physically associated with an 8-cm-long assumed anthracitic axis on one of the larger rock slabs (phyllite) described by Leo Lesquereux from the Southern Anthracite Field, USA. The fragmentary fossils, not larger than 1.6 mm, resemble microscopically ‘fossilized-cuticles’. Additionally, observed are 10–28 μm diametric bodies reminiscent of spores. Effectively demonstrated is the co-occurrence of two preservation modes of plant material: (1) as assumed anthracitic axis; and (2), as ‘fossilized-cuticle’ in a metamorphic environment. An organometallic process is hypothesized for stabilizing the preservation states with novel research potential for plant-fossil preservation in an anthracitic terrain.

New spinosaurids from the Wessex Formation (Early Cretaceous, UK) and the European origins of Spinosauridae

Spinosaurids are among the most distinctive and yet poorly-known of large-bodied theropod dinosaurs, a situation exacerbated by their mostly fragmentary fossil record and competing views regarding their palaeobiology. Here, we report two new Early Cretaceous spinosaurid specimens from the Wessex Formation (Barremian) of the Isle of Wight. Large-scale phylogenetic analyses using parsimony and Bayesian techniques recover the pair in a new clade within Baryonychinae that also includes the hypodigm of the African spinosaurid Suchomimus. Both specimens represent distinct and novel taxa, herein named Ceratosuchops inferodios gen. et sp. nov. and Riparovenator milnerae gen. et sp. nov. A palaeogeographic reconstruction suggests a European origin for Spinosauridae, with at least two dispersal events into Africa. These new finds provide welcome information on poorly sampled areas of spinosaurid anatomy, suggest that sympatry was present and potentially common in baryonychines and spinosaurids as a whole, and contribute to updated palaeobiogeographic reconstructions for the clade.

A Triassic stem lepidosaur illuminates the origin of lizard-like reptiles.

The early evolution of diapsid reptiles is marked by a deep contrast between our knowledge of the origin and early evolution of archosauromorphs (crocodiles, avian and non-avian dinosaurs) to that of lepidosauromorphs (squamates (lizards, snakes) and sphenodontians (tuataras)). Whereas the former include hundreds of fossil species across various lineages during the Triassic period1, the latter are represented by an extremely patchy early fossil record comprising only a handful of fragmentary fossils, most of which have uncertain phylogenetic affinities and are confined to Europe1-3. Here we report the discovery of a three-dimensionally preserved reptile skull, assigned as Taytalura alcoberi gen. et sp. nov., from the Late Triassic epoch of Argentina that is robustly inferred phylogenetically as the earliest evolving lepidosauromorph, using various data types and optimality criteria. Micro-computed tomography scans of this skull reveal details about the origin of the lepidosaurian skull from early diapsids, suggesting thatseveral traits traditionally associated with sphenodontians in fact originated much earlier in lepidosauromorph evolution. Taytalura suggests that the strongly evolutionarily conserved skull architecture of sphenodontians represents the plesiomorphic condition for all lepidosaurs, that stem and crown lepidosaurs were contemporaries for at least ten million years during the Triassic, and that early lepidosauromorphs had a much broader geographical distribution than has previously been thought.

New stegosaurs from the Middle Jurassic Lower Member of the Shaximiao Formation of Chongqing, China

ABSTRACT Stegosaurs are a major clade of ornithischian dinosaurs, yet because of their fragmentary fossil record, their interrelationships and early evolution are poorly understood. Here, we describe a new stegosaur, Bashanosaurus primitivus, gen. et sp. nov., and some other indeterminate stegosaur materials. We provide new U-Pb detrital zircon ages for horizons bounding the holotypic quarry in the Lower Member of the Shaximiao Formation, Yunyang, Chongqing Municipality, China, which indicate a Middle Jurassic (Bajocian) age. Bashanosaurus represents the earliest record of stegosaurs in Asia and one of the earliest records of this clade in the world. The dorsal vertebrae, scapula, coracoid, femur, and plates of Bashanosaurus primitivus possess several unique characters among Stegosauria, including the elevation of the parapophyses of dorsal vertebrae on stalks at the base of the transverse processes, a flared distal end of the scapula, and a small acromial process. Among armored dinosaurs (thyreophorans), these features are reminiscent of the basally branching taxon Scelidosaurus, indicating that Bashanosaurus possesses a unique mosaic of plesiomorphic thyreophoran and derived stegosaur features. Phylogenetic analysis shows that Bashanosaurus primitivus is the earliest-diverging stegosaur, along with Chungkingosaurus, from the Upper Member of the Shaximiao Formation, consistent with the early age of the taxon.

Lower Devonian (Pragian–Emsian) land plants from Alexandra: an early window into the diversity of Victorian flora from southeastern Australia

Numerous fragmentary plant fossils are described from the Lower Devonian outcrops near Alexandra, Victoria, southeastern Australia. These outcrops include Eglinton Cutting and two road cuttings on Mount Pleasant and Halls Flat roads previously examined by Isabel Cookson in 1935. Most plants are preserved as iron-stained impressions or coalified compressions lacking internal anatomy in fine-grained sandstone and siltstone. The vast majority of specimens examined proved to be little more than naked fragmentary axes often distributed seemingly randomly; it is the exceptions to these that are examined herein. Most of these specimens belong to the zosterophylls and isolated axes with emergences suggestive of a Gosslingiaceae affinity. Significantly, one specimen attributable to Cooksonia Lang, 1937, renalioid-like sporangia and specimens with isolated sporangia with emergences are recorded for the first time from Victoria. A discussion follows examining the possible reasons for the differences between the Alexandra and Walhalla assemblages, and it is postulated that the differing palaeocurrents indicate the terrestrial sources were from opposite directions. This easterly source for the Walhalla assemblage suggests a subaerial environment may have existed on the eastern side of the Melbourne Zone during the deposition of the Norton Gully Sandstone, earlier than the fluvial deposits of the Middle Devonian Cathedral Beds. Fearghus R. McSweeney FGS [ tidal75@gmail.com ], School of Science, RMIT University, Swanston Street, Melbourne 3000, Australia; Jeff Shimeta [ jeff.shimeta@rmit.edu.au ], School of Science, RMIT University, Swanston Street, Melbourne 3000, Australia; John St. J. S. Buckeridge FGS [ john.buckeridge@rmit.edu.au ], Earth & Oceanic Systems Group, RMIT University, GPO Box 2476.