Although Banffia constricta was first described in 1911, the affinities of this soft-bodied fossil animal have remained unclear. Banffia is redescribed here, on the basis of over 300 specimens. Banffia has a bipartite body measuring up to 10 cm in length. The entire body is axially twisted along a spiral, clockwise as seen from the front. The anterior section consists of two fused carapace-like units with a prominent crown-like structure at the anterior end surrounding the mouth. This crown-like structure is composed of three concentric circlets. A single antenniform outgrowth lies posterior to the mouth. The posterior section of Banffia is composed of 40 to 50 lightly sclerotised segments. The anus is terminal, and situated in a caudal notch. The gut is straight. Simple serially repeated structures along the gut may represent metameric mid-gut diverticulae. Banffia is considered to have been an epibenthic gregarious animal and possibly a deposit-feeder.

Banffia is putatively classified as an end-member of the phylum Vetulicolia, in a new class, the Banffozoa. If the vetulicolids represent a stem-group deuterostome, the absence of gills and a possible endostyle in Banffia is problematic. The presence of mid-gut diverticulae in Banffia may represent a link with the protostomes.

The Late Ordovician–Early Silurian succession in Jämtland includes the marine Kogsta Siltstone, which is unconformably overlain by the shallow-water Ede Quartzite that grades into the open-marine Berge Limestone. A Hirnantia shelly fauna dates the uppermost Kogsta Siltstone as Hirnantian, and shelly fossils indicate an Aeronian age for the Berge Limestone. Biostratigraphically highly diagnostic conodonts of the early-middle Aeronian Pranognathus tenuis Zone provide the first firm date of the Upper Ede Quartzite and the lowermost Berge Limestone. The Lower Ede Quartzite has not yielded fossils, but sedimentological data suggest it to be of Hirnantian age and reflect the glacio-eustatic low-stand. The contact between the Lower and Upper Ede Quartzite, here taken to be the Ordovician–Silurian boundary, appears to be an unconformity associated with a stratigraphic gap that at least includes the Rhuddanian Stage. The biostratigraphically important conodonts Pranognathus tenuis, Kockelella? manitoulinensis, and Pranognathus siluricus are recorded from Sweden for the first time, and these and other conodonts are used for correlations with coeval units in Europe and North America. In a regional review of Aeronian conodont faunas, three intergrading, apparently depth-related, conodont biofacies are recognised, the Jämtland conodonts representing the one characteristic of the shallowest water.

Direct fossil evidence of scavenging ostracods is rare. A convincing example, representing the earliest recorded occurrence of ostracods feeding on vertebrate carrion, is described from the Bowland Shale Formation (Kinderscoutian, Upper Carboniferous) of Derbyshire, UK. It consists of the anterior end of a shark (Orodus sp.) whose upper surface is crowded with adults and juveniles of the nektobenthic ostracod Eocypridina carsingtonensis Wilkinson, Williams, Siveter & Wilby, 2004 (Myodocopida: Cypridinidae). Extrapolation of their preserved density suggests that the entire carcass may have hosted over a thousand individuals. It presented a rare opportunity for benthic scavenging in the Widmerpool Gulf because it was sufficiently large to have protruded above the inhospitable, and probably soupy, substrate surface. Although not necessarily a necrophagous specialist, E. carsingtonensis appears to have been well adapted to rapidly locating and exploiting widely dispersed nekton food drops. Its absence from the background sediment suggests that it commuted to the shark over relatively large distances, probably from adjacent basin highs. This implies a well-developed chemosensory capability. The ostracods are interpreted as having been overwhelmed by sediment dislodged during the sudden collapse of the partially buried carcass.

A description of the head, mandible, pectoral girdle, humerus, medial fins and their supports, and the dissociated vertebral column has been prepared for Onychodus jandemarrai n. sp. from the Gogo Formation (Frasnian) of Western Australia. This is the most completely known species of the genus. The feature influencing most of the head morphology is the retractable parasymphysial tusk whorls. Their presence has caused a reorganisation of the braincase, palate (including the loss of the vomers), and lateral displacement of the nasal capsules. The extensive mandibular articulation is in cartilage, and the mandibular symphysis is weak. This makes for a kinetic skull. There is a single submandibular on each side. The vertebral column is poorly ossified, consisting of intercentra which have no ventral contact, and pleurocentra. The neural arches have no longitudinal ligament, have unequal sides, and asymmetrical placing of the dorsal and ventral nerve root foramina. Each arch has an anterior surface that often attaches to the next anterior arch. The caudal fin is almost diphycercal; all the medial fins have strong support structures. An attempt is made to discuss the functional morphology of many features of the skeleton.

Comparisons of the Caradoc assemblages with North American biofacies indicate that the Bardahessiagh Formation was deposited during a transgressive regime, which peaked with the presence of a typical Sericoidea association (member (II)). These diverse and exceptionally preserved faunas lived below the storm-wave base. The assemblages also contained a shallower water brachiopod component typical of transition zone environments or above, which may have been transported during periods of instability. A deep-water regime (BAs 4 to 4–5) through the Rawtheyan occurs with the deposition of the Killey Bridge Formation, which yielded a diverse brachiopod fauna including Bimuria, Chonetoidea and Christiania. The Rawtheyan assemblage also contains a shallower water component. Representatives of the deep-water Proboscisambon assemblage occur in middle parts of the Tirnaskea Formation. This distinctive low-diversity assemblage yields small, thin-shelled brachiopods including Dedzetina, Sericoidea, Protozyga and Proboscisambon. The upper parts of the Tirnaskea Formation yielded the low diversity, shallow water (BA 3) Hirnantia fauna, which is characterised by the presence of Eostropheodonta, which is a key form of the fauna, Dysprosorthis and the absence of Hirnantia. As a whole the changing brachiopod biofacies monitor environmental fluctuations, on part of the Laurentian margin, driven mainly by eustatic and tectonic events.

The protaspid ontogeny of Bolaspidella housensis (Walcott, 1886) is re-described. This species is known from the Marjum Formation (Lower Marjuman Stage) of western Utah, USA. Three protaspid stages are recognised, with the instars discriminated most readily by different spacing between the postero-lateral ends of the fixigena. Protaspides of B. housensis are shown to be similar to those of Glaphyraspis parva, from several Upper Cambrian localities in the USA, and Ptychopariide sp. E from the Upper Cambrian of the Wasatch Mountains in Utah, USA.

The presence of a petaloid pattern (previously known as ‘dark dentine’) in cross sections of teeth of the embolomere Pholiderpeton attheyi has been used as a synapomorphy of the embolomeres or of the embolomeres plus the stem tetrapod, Crassigyrinus scoticus. Among the taxa studied, dentine that appears dark results from closely packed dentine tubules and can be found in any part of a tooth section in which such crowding occurs. The petaloid pattern is restricted to tooth sections of a particular diameter, and is obliterated in larger sections of teeth that show complex folding. Petaloid dentine has been found in all tetrapod teeth with plicidentine that were sectioned in this study, whether from stem tetrapods, the Embolomeri, Temnospondyli, or Stereospondyli, and has been recognised in some sarcopterygian fish, an extant actinopterygian fish, ichthyosaurs, and Varanus. The presence of petaloid dentine is neither a synapomorphy of the tetrapod node nor of any node within tetrapods

Morphology and ontogenetic changes in the skull and hyobranchium of the Permo-Carboniferous temnospondyl Archegosaurus decheni from the Saar–Nahe Basin (SW Germany) are described in detail, based on 181 skulls ranging from 18 to 279 mm in length. Three-dimensional skull reconstructions including the palate of different growth stages are provided. The extremely elongate choanae and up to four median symphyseal teeth are unique to A. decheni. Among neurocranial elements, the exoccipital is well ossified and forms the paroccipital process as in stereospondyls. The shaft of the stapes which projects into the squamosal embayment grows with positive allometry and possesses a distinct lateral process. The basibranchial is well ossified in adults and exhibits a complex, spoon-like morphology. Small larvae were euryphagous and used non-directed suction and jaw prehension during prey capture. Larger larvae and adults were mainly ichthyophagous, as is indicated by the increasingly elongated snout, differentiation of marginal teeth, and nutrition remains. After a prolonged larval period, juvenile and adult A. decheni remained in the aquatic habitat, as suggested by the presence of lateral line sulci, the ‘aquatic type’ of septomaxilla and choana, and the absence of a nasolacrimal duct.

A new aglaspidid arthropod, Chlupacaris dubia gen. et sp. nov., is described from the Pusgillian (lower Ashgill, Upper Ordovician) Upper Tiouririne Formation near Erfoud, southeastern Morocco. Although disarticulated, careful documenting of the tergites allows a reconstruction of the exoskeleton to be made. Although somewhat trilobite-like in appearance, the lack of facial sutures, a well-defined axis with articulating half-rings and a pygidium clearly prove Chlupacaris gen. nov. is not a trilobite. An interesting feature is the presence of a hypostome in this non-trilobite arthropod. In contrast to other aglaspidids usually considered to be carnivorous, a filter-feeding mode of life is proposed for Chlupacaris gen. nov., based on the strongly vaulted cephalon, subvertical orientation of the hypostome and less strongly vaulted trunk. Chlupacaris gen. nov. is probably most closely related to the atypical aglaspidid Tremaglaspis unite from the Tremadoc (Lower Ordovician) of the U.K., but it can also be tentatively linked to the problematic Lower Cambrian arthropods Kodymirus vagans and Kockurus grandis from the Czech Republic. The relevance and validity of previous definitions and of possibly significant characters used for identifying aglaspidids are evaluated, and as a result, a new combination of characters diagnosing Aglaspidida is proposed. Contrary to previous reports, it is suggested that aglaspidids are probably more closely related to trilobites than they are to chelicerates. This notion may be supported by the shared possession of a mineralised cuticle, a possibly similar number of cephalic appendages, and the presence of a hypostome in some forms, although this last character may alternatively be homoplastic.

Redescription of the cranial anatomy of Ariekanerpeton sigalovi (Seymouriamorpha: Discosauriscidae; Lower Permian, Tadzhikistan) highlights new diagnostic features which permit a new skull reconstruction and revised diagnosis. The largest Ariekanerpeton specimens differ from like-sized Discosauriscus, a second member of Discosauriscidae, in showing: oblique anterior margin of tabular ornamented surface; acute, elongate posterolateral corner of supratemporal; postorbital ventrolateral ramus with small anteroventral process and forming oblique suture with jugal dorsomedial ramus; jugal posterior ramus tapering rearward, forming subhorizontal suture with quadratojugal; weak ventral sculpture lateral to pterygoid articular recess; parasphenoid subrhomboidal, with lightly sculptured anterior wedge-like process; more densely arranged denticle rows on top of low radiating ridges on pterygoid palatal ramus. Gill filaments occur in specimens with skull lengths of up to 30 mm. Detailed examination of ontogenetic changes in Ariekanerpeton and comparisons with other seymouriamorphs are presented.

The postcranial skeleton of Ariekanerpeton sigalovi (Seymouriamorpha: Discosauriscidae; Lower Permian, Tadzhikistan) differs from that of like-sized Discosauriscus specimens in showing: wider interclavicle anterior plate with smaller, rhomboidal sculptured field on its ventral surface not reaching plate posteromedial margins; broader interclavicle plate-stem junction; slightly narrower interclavicle posterior stem; anteroposteriorly narrower clavicle ventral plate with convex posterior margin; shorter, more robust humerus; four phalanges on fourth manus digit (five phalanges in Discosauriscus); ilium more elongate dorsoventrally with anteroposteriorly narrower neck; posterior process of iliac blade oriented distinctly posterodorsally rather than horizontally; more gracile atlantal rib; broadened distal end of second presacral rib. A revised cladistic analysis of the best known seymouriamorph species retrieves Ariekanerpeton either as sister group to both species of Discosauriscus, or to D. austriacus only.

Non-marine Bathonian (Middle Jurassic) strata on the Isles of Eigg and Skye in Scotland have yielded fossil remains of eight hybodont shark taxa. Faunas from several horizons within the Lealt Shale and Valtos Formation on the Isle of Eigg include six species: Hybodus grossiconus, Hybodus sp. 1, Hybodus sp. 2, Lissodus leiodus, L. leiopleurus and Parvodus pattersoni. Large collections of teeth of L. leiodus and L. leiopleurus enable a better understanding of the dentitional patterns of the two species and their differential diagnosis. Surface-collecting from exposures of the Kilmalaug Formation on the Isle of Skye yielded hybodont teeth of two taxa: Hybodus sp. 3 and Acrodus caledonicus sp. nov. The occurrence of Acrodus in the Bathonian of Scotland is one of the youngest known occurrences of this genus, and the only non-marine record in the European Jurassic. Collectively, the hybodont assemblages from the Scottish Bathonian provide evidence that non-marine faunas of the group were specifically diverse in the Middle Jurassic.

Pentastomida, tongue worms, are a taxon of about 130 species of parasites, living exclusively in the respiratory tracts of vertebrates. Three-dimensionally preserved Upper Cambrian larvae already demonstrate a high degree of adaptation to parasitism, striking morphological conservatism, and a high diversification by the Late Cambrian, thereby suggesting a likewise diversified host group. Not least due to their highly modified morphology, the systematic affinities of pentastomids remain controversial. The two major alternatives place the group as either close to branchiuran crustaceans or as stem-lineage derivatives of the Euarthropoda. To this set of Cambrian fossil representatives of the pentastomids we can add a new form from Lower Ordovician boundary beds from Sweden, most likely reworked from Upper Cambrian horizons. Based on this new species, named Aengapentastomum andresi gen. et sp. nov., and the available information about fossil and Recent pentastomids, we review the diverging ideas on the systematic position of this fully parasitic taxon.

Five new fossil species of the Recent genus of blood-feeding sand flies Lutzomyia (Psychodidae: Phlebotominae) are described: L. filipalpis, L. miocena, L. paleopestis, L. schleei, and L. succini. All are preserved in Miocene amber from the Dominican Republic; today Hispaniola harbours only two known species of this genus. Recent Lutzomyia feed on a wide variety of terrestrial vertebrates, including reptiles, birds, and mammals. Three rare pieces of the amber are reported, two described in detail, which preserved assemblages of Lutzomyia swarms with strands of mammalian hair, indicating that at least some of the fossil species were mammal feeders. Microstructure of the fossil hair offers little diagnostic evidence, but is very similar to that of insectivores in the Solenodontidae. Further preserved evidence indicates that the fossil midges swarmed about an arboreal nest or site of decayed wood that was worked by a mammal, but at very specific times during formation of the amber. Other very rare Dominican amber pieces containing a flea and an ixodid tick also contain mammalian hairs of similar microstructure, together with Lutzomyia sandflies, possibly reflecting the ectoparasite community of a Miocene mammal. This parasitic association has implications regarding the evolution of vectors of mammalian pathogens like Leishmania and the study further reveals the extent of palaeobiological inference that is possible with amber.

The development of the skeleton of the small temnospondyl Acanthostomatops vorax is described, based on 32 specimens from the Lower Rotliegend of Niederhäslich in Saxony. Both individually and ontogenetically, the skull table, length of gape, and dentition of the parasphenoid are broadly variable. The stapes has a short and straight shaft and a well-defined two-headed proximal region. Small specimens have three or four pairs of ossified ceratobranchials in the gill region, while the adult hyobranchium is composed of four pairs of hypobranchials and probably some additional elements. The postcranium is characterised by a stout and well-ossified humerus that is already large in small larvae, a minute rectangular interclavicle, a robust but short femur, a relatively short trunk with 21–22 presacrals and a moderate tail with 28 vertebrae. In adults, the trunk skeleton became proportionally shorter and the femur smaller with respect to skull length. Metamorphosis is best indicated by the disappearance of the larval gill skeleton, which was probably resorbed, while the structure of the limbs and axial skeleton as well as the absence of lateral line sulci suggest a terrestrial existence for adults.

This paper describes extensive new collections of ammonites made bed-by-bed across the Oxfordian/Kimmeridgian boundary sequence in the Flodigarry sections at Staffin Bay on the Isle of Skye. The ammonites belong to the Sub-Boreal family Aulacostephanidae and the Boreal family Cardioceratidae, enabling recognition of both the current standard Sub-Boreal and Boreal ammonite zonations. In consequence, it is possible to make a close correlation of these two zonal schemes through the interval studied in Skye. The research has provided new palaeontological data at levels of precision that justify the proposal of the section at Staffin as the site of a potential Global Boundary Stratotype Section and Point (GSSP) for the Oxfordian/Kimmeridgian boundary.

The traditional Oxfordian/Kimmeridgian boundary placed at the Pseudocordata/Baylei zonal boundary of the Sub-Boreal zonal scheme corresponds precisely to the Rosenkrantzi/Bauhini zonal boundary of the Boreal zonal scheme. This level is characterised by the appearance of the first Pictonia (Pictonia flodigarriensis sp. nov.) together with first Prorasenia, replacing an older assemblage of Ringsteadia–Microbiplices (Sub-Boreal). It is also characterised by the first occurrence of small-sized Amoeboceras (Plasmatites) spp., as well as large Amoeboceras schulginae Mesezhnikov (Boreal). An alternative level that may be considered as a potential GSSP is the boundary between the Bauhini Zone and the Kitchini Zone of the Boreal zonal scheme, characterised by first occurrence of Amoeboceras (Amoebites) of the A. bayi group. This level corresponds to the Planula/Galar subzonal boundary of the Sub-Mediterranean zonal scheme, and lies close to the currently accepted Oxfordian/Kimmeridgian boundary in the Sub-Mediterranean Province.