The fossil record of dinosaurs in Scotland mostly comprises isolated highly fragmentary bones from the Great Estuarine Group in the Inner Hebrides (Bajocian–Bathonian). Here we report the first definite dinosaur body fossil ever found in Scotland (historically), having been discovered in 1973, but not collected until 45 years later. It is the first and most complete partial dinosaur skeleton currently known from Scotland. NMS G.2023.19.1 was recovered from a challenging foreshore location in the Isle of Skye, and transported to harbour in a semi-rigid inflatable boat towed by a motor boat. After manual preparation, micro-CT scanning was carried out, but this did not aid in identification. Among many unidentifiable elements, a neural arch, two ribs and part of the ilium are described herein, and their features indicate that this was a cerapodan or ornithopod dinosaur. Histological thin sections of one of the ribs support this identification, indicating an individual at least eight years of age, growing slowly at the time of death. If ornithopodan, as our data suggest, it could represent the world's oldest body fossil of this clade.

The organic-rich shales and mudstones composing the Miaolingian (‘middle’ Cambrian) through Tremadocian (Lower Ordovician) Alum Shale Formation have been extensively mined for production of alum at Andrarum in southeastern Scania (Skåne), southern Sweden. Here, the formation was exploited between 1637 and 1912, and a brief account is given of the history of the exploitation. The alum industry had its heyday in the mid-1700s when it was owned by Christina Piper (1673–1752). During this time some 900 people lived within the working area, and it had its own craftsmen, school, hospital and courthouse with a jail annex. The undeformed and virtually continuous succession at Andrarum is generally richly fossiliferous and, albeit largely covered by scree and vegetation, best exposed in the old quarries. The fossil faunas are dominated by trilobites and agnostoids, which form the basis for a detailed biostratigraphical framework. The history of geological and palaeontological research at Andrarum, since the pioneering works in the mid- to late 1800s, is reviewed. The sequence of strata was first elucidated by Alfred Gabriel Nathorst in 1869. Since then, the succession and its fossil content have been studied by a considerable number of influential researchers, such as Gustaf Linnarsson (1841–1881), Sven Axel Tullberg (1852–1886) and Anton H. Westergård (1880–1968). In the decades around the turn of the 21st century, Euan Clarkson initiated a number of projects focusing on the ontogeny, evolution and functional morphology of olenid trilobites from the Furongian at Andrarum, along with two important studies dealing with faunal dynamics and biotic turnovers. His research resulted in a series of pivotal papers on the geology and palaeontology of the Alum Shales.

In 1952, Erik Jarvik diagnosed and offered a brief description of the large-bodied, highly nested tristichopterid taxon Eusthenodon, and its type species E. wangsjoi, from fossils recovered from the Britta Dal Formation (Famennian) of Gauss Halvø ( = Peninsula) and Ymer Ø ( = Island) in East Greenland. The original diagnosis for Eusthenodon only needed to distinguish the tristichopterid taxon from the two others known at the time, Eusthenopteron and Tristichopterus, both of them small-bodied forms with anatomy now recognised to be primitive within the clade. Following that publication, no new large-bodied tristichopterids with Eusthenodon-like characteristics would be introduced until the description of Mandageria fairfaxi in 1997. In the 45 interim years, the limited descriptive details and insufficient diagnosis of Eusthenodon turned the name into a broadly applicable taxonomic label for large-bodied tristichopterid discoveries. Recent efforts to rediagnose the taxon and reconsider its global distribution of referred materials have improved the taxonomic utility of the name. However, no complete description of type species E. wangsjoi has yet been written. This is despite a type series of specimens that includes complete and articulated skulls that remain available for study in the collections of the Natural History Museum of Denmark (NHMD). The work presented here fulfils the need for a complete comparative description of E. wangsjoi in the context of the many highly nested tristichopterid species that have been described in the last three decades. New figures of the E. wangsjoi type series of specimens are the first to offer views of the fossils unobscured by the superimposition of interpretive line drawings. The new description is accompanied by a descriptive inventory of all the potential E. wangsjoi fossils at the NHMD and a new phylogenetic analysis of clade Tristichopteridae that includes revised character data for E. wangsjoi and adds one recently described species.

With extraordinary preservation, the bivalved Cassicaris clarksoni gen. et sp. nov. from the early Cambrian (Stage 3) Xiaoshiba Lagerstätte in Kunming, China, is characterised by having an anterior cardinal spine and a heavily segmented body, including an abdomen with a heavily sclerotised shell. Anatomically, the antennulae are small and the antennae are robust with seta-bearing podomeres, possibly of predatory function, followed by the other five pairs of biramous cephalic limbs. There are about 11 pairs of thorax segments, each corresponding to a pair of biramous limbs, including a multi-segmented endopod with feather-like podomeres and terminal spines, and a small paddle-shaped exopod fringed with setae. The bulbous, stalked eyes, which exhibit fineness of vision, infer adaptation to a vagile epibenthic lifestyle. Functionally, such assorted appendages may indicate an efficient suspension-feeding strategy for capturing tiny zooplankton. The median eye is presumably not a typical ocellar system but another compound eye, which may offer further insights into the evolution of compound eyes. Cladistic analysis implies that Cassicaris is a sister taxon to Pectocaris and Jugatacaris; these intriguing euarthropods are critical for discerning their body plan and living habits. Our findings offer fresh insights into the early evolution of Cambrian euarthropods, characterised by notable morphological disparity and ecological diversity. These fossils, including not only many intact individuals but also a few with well-preserved soft parts, form well-characterised groupings, making the broad pattern of Cambrian arthropod systematics increasingly consensual.

This study examines foraminifers from limestone horizons of the mainly Brigantian Lower Limestone Formation across the Midland Valley of Scotland (MVS), to determine more precisely the correlation of the limestone beds throughout the region and with the marine bands. Three quantitative biostratigraphical methods were applied to the foraminiferal dataset. The Ranking and Scaling method produced unusual mixed associations and a ranked optimum sequence, making it the least reliable. In contrast, the Unitary Associations (UA) and Constrained Optimization (CONOP) methods yielded more consistent sequences and correlations, especially the latter. The main conclusions drawn were: (i) The West Kirkton, First Abden and St Monans Brecciated limestones of the eastern MVS are considered the base of the Lower Limestone Formation; (ii) The Petershill Limestone is considered as the likely lateral equivalent of the Blackhall Limestone; (iii) the Seafield Tower, Charlestown Main and Middle Skateraw limestones can be correlated in the eastern MVS; (iv) the Abden Fauna (marine band) in central Fife, is confirmed just below the base of the Lower Limestone Formation in most sections; and (v) correlation of limestones below the Neilson Shell Band (marine band) in the eastern region is confirmed with the CONOP method, and in the western region with the Unitary Associations.

Cambrian trilobites from two separate allochthonous limestone blocks of La Cruz olistoliths at the Quebrada Oblicua (Precordillera of Mendoza, Argentina), originally described by the naturalist Carlos Rusconi in the 1950s, are revised herein. One of the olistoliths is dominated by the late Guzhangian cedariid Cedaria puelchana Rusconi, whereas the other block contains Pseudagnostus cf. P. idalis Öpik, Dunderbergia punctata (Rusconi) new combination, Sigmocheilus cf. S. sigmoidalis (Palmer), Litocephalus obliquoanus (Rusconi) new combination, and Onchonotopsidae? gen. et sp. indet., which indicate a late Paibian age (Dunderbergia Zone). The genera Dunderbergia Walcott (=Tabalqueia Rusconi), Sigmocheilus Palmer, and Litocephalus Resser (=Cayupania Rusconi) are reported from South America for the first time. In line with previous studies on Cambrian faunas from the Precordillera, the assemblages revised here show North American (Laurentian) affinities.

The Paatusoq region of Greenland is a spectacular, exhumed subvolcanic system with horizontal and vertical (<2.5 km) sections preserved, making it an ideal natural laboratory to study magmatism. Two intrusive centres, a gabbro and syenite, are exposed. The gabbro contains a layered centre and an unlayered margin, with augite monzodiorite and olivine gabbro units. The layering contains channel and slump structures but is gravitationally inverted with plagioclase on the bases of layers grading up into denser mafic minerals at the top. Incompatible element geochemistry and field evidence indicate it is related to the Ketilidian Orogeny. The syenite complex comprises three major syenite units which young from W to E. U-Pb geochronology confirms Paatusoq as the youngest Gardar intrusive centre at 1140 Ma, emplaced over a timescale of <1 Ma, and its proximity to the Paatusoq Gabbro Centre is fortuitous. The mineralogy of each syenite unit is dominated by a primocryst framework of crypto- and micro-perthitic alkali feldspar with interstitial feldspar, pyroxene, amphibole ± quartz. A transsolvus feldspar assemblage of interstitial discrete grains of plagioclase and potassium feldspar alongside quartz and granophyre (i.e., vermicular intergrowth of quartz and K-feldspar) between microperthite primocrysts indicates that water and silica increased significantly in the latter stages of crystallisation. Coalescence and migration of interstitial melt is inferred to have produced irregular alkali granite and biotite syenodiorite bodies which cut the syenites. Hydrothermal alteration of hedenbergite in syenite created aligned lamellae of magnetite in pyroxene and the formation of hydrated ferric oxides which stained some units a characteristic orange colour. Paatusoq is a fascinating, deeply dissected slice through a subvolcanic magma system, providing evidence for crustal contamination and melt migration. Comparison of the Paatusoq Syenite Complex with other Gardar centres provides insights into processes that occur during continental rift magmatism.

The distinctive isolated elements of Cynopodius, characterised by their deep narrow base and spatulate crown, were first described (as spine-like elements) by Ramsay Heatley Traquair in the late 19th Century, based on specimens from the Burghlee Ironstone (Serpukhovian, Carboniferous) at Loanhead near Edinburgh, Scotland. The type species Cynopodius crenulatus is also known from older Calciferous Sandstone Measures (Viséan) of Fife. Here we provide evidence that the elements are teeth rather than spines or dermal claspers, as hypothesised elsewhere. Thin sections of the teeth, illustrated for the first time, show osteodentine and tubate dentine forming the crown, covered by a thin outer hypermineralised layer on the cusps, and trabecular osteodentine or acellular bone forming the base. In recent decades, teeth of Cynopodius have also been collected from the lower Carboniferous Sainte Genevieve Formation (Mississippian: Viséan) of Iowa, Kentucky, and West Virginia in the USA. We assign these teeth from Iowa to Cynopodius robustus n. sp. They are distinguished from the type species by their relative robustness, with a ratio of maximum crown length to root length of c. 2:3 for C. traquairi and c. 1:2 for C. crenulatus, and lack of longitudinal curvature. The Scottish and American occurrences, though widely separated in the early Carboniferous, are the only known localities for the genus. The similarity between these over 300-million-year-old teeth and those of Recent long-toothed teleost reef fishes like Ctenochaetus, for instance, suggests that the Cynopodius animals might also have been specialised detritivores.

The macrofossil record of the lower Palaeozoic Stavelot-Venn Inlier is revised. This inlier is the largest of the four inliers of the Ardenne Allochthon in southern Belgium and northern France, and it extends from southeastern Belgium into western Germany. The thick succession of mostly siliciclastic rocks has been traditionally assigned to the lower Cambrian to Middle Ordovician, but macrofossils are extremely rare and the microfossil (acritarch) records need revision. The presence of the ichnogenus Oldhamia indicates an early/middle Cambrian age for the lower (but not lowest) part of the succession. The graptolites from the Rhabdinopora fauna clearly point out the presence of the Tremadocian (Lower Ordovician) strata; they are locally associated with small linguliformean brachiopods (e.g., Broeggeria, Lingulella). The present revision, based on examination of the Belgian material, indicates that none of the trilobite, phyllocarid and sponge records in the literature can be confirmed. From all macrofossils mentioned in the literature, only few linguliformean brachiopod levels can be confirmed in the (? middle–upper) Cambrian and in the Lower Ordovician. The alleged bivalve from the Cambrian of the French part of the Rocroi Inlier is reillustrated.

A factor analysis of an exhaustive sample-based dataset of Cambrian (Miaolingian) to Silurian radiolarian species occurrences allows the detection of three evolutionary faunas composed of specific radiolarian families, which record simultaneous increases and decreases in radiolarian species richness over geological time. The oldest evolutionary fauna is composed of Cambrian to Early Ordovician archaeospicularians, assigned to the families Echidninidae and Palaeospiculidae, and of the entactinarian family Protoentactiniidae. This evolutionary fauna is complemented in the Early Ordovician by the oldest spumellarian family Antygoporidae, as well as by the order incertae sedis families Aspiculidae and Proventocitidae. Next, a new evolutionary fauna emerged during the Darriwilian and persisted during the Sandbian; it is dominated by the spumellarian family Inaniguttidae and to a lesser extent by the entactinarian families Haplentactiniidae, Entactiniidae and Pylentonemidae. Last, a third evolutionary fauna emerged since the Katian (Late Ordovician) and continued during the entire Silurian; it is dominated by the archaeospicularian family Secuicollactidae, the entactinarian family Paleoscenidiidae and the spumellarian family Haplotaeniatidae. These three early Palaeozoic radiolarian evolutionary faunas seem to correlate with major climatic and biotic changes known in the Ordovician: (i) the transition between the first and second evolutionary faunas is sharp and underlined by profound changes in taxonomic composition and turnover during the Middle Ordovician; it is correlated with the sudden early Darriwilian climate shift, global cooling and the main phase of the Great Ordovician Biodiversification Event (GOBE); (ii) the transition between the second and third evolutionary faunas is correlated with the Late Ordovician mass extinction (LOME; Katian–Hirnantian) and associated climate cooling.

Graptolites of the Pleurograptus linearis Biozone have long been known to straddle the boundary between the British Caradoc and Ashgill series (C/A) of the Ordovician. This is largely based on observations of these graptolites in the Whitehouse Subgroup of the Girvan area in Scotland. However, in the type Cautleyan-Rawtheyan area of northern England, graptolites of the same biozone range into the Rawtheyan Stage of the Ashgill Series, impacting the utility of the P. linearis Biozone for regional and global correlation around the C/A boundary. Here we use chitinozoan microfossils to correlate the strata in Girvan and Cautley in an independent manner. We present new chitinozoan data from an exhaustive sampling effort across the Whitehouse Subgroup from several locations in Girvan and correlate these with other key sections that contain graptolites from the P. linearis Biozone and index chitinozoans of Baltoscandian–Avalonian and Laurentian zonal schemes. During the Late Ordovician, Girvan occupied a pivotal geographical position allowing linkages between Laurentian faunas and those of both Baltica and Avalonia. Our samples yielded some typical Laurentian chitinozoan species (e.g., Hercochitina cristata, Kalochitina multispinata), next to several well-known index species of mixed Baltoscandian–Avalonian affinity, relatable to the Fungochitina spinifera and Tanuchitina bergstroemi biozones and their subzones; the latter can be traced into key areas of Ordovician stratigraphy in England and Wales on Avalonia, and Denmark and Sweden on Baltica. These correlations suggest that the P. linearis Biozone at Girvan correlates to an interval starting in the Onnian and extending into some part of the (lower) Cautleyan Stage at Cautley, northern England. The Girvan district is confirmed as a key area to document mixed faunas from Laurentian–Avalonian–Baltic realms, and has potential as a stepping stone between rather distinct chitinozoan provinces.

Bohemilla (Bohemilla) scotica Reed, 1914 and B. (B.) xesta sp. nov. are described from the middle Katian (around the Caradoc–Ashgill boundary in terms of the regional chronostratigraphical scheme) of the Girvan district of SW Scotland. Their occurrence in the Upper Whitehouse Subgroup of the Ardmillan Group is in the youngest recorded part of the range of the genus. Their association with a diverse deep-water trilobite fauna, including members of the cyclopygid biofacies, accords well with the earlier occurrences of the genus that first appeared in the Early Ordovician. The earlier history of Bohemilla was largely at higher latitudes and its occurrence at Girvan, and probably at a broadly equivalent stratigraphical level in Ireland, marks the extension of the range of the genus to the Laurentian margin of the Iapetus Ocean in the latest part of its history.

There are numerous reports of trilobites that survived macrophagous attacks and whose injuries healed. Significantly, rarely observed, however, are such repaired injuries to the head or especially to the eyes. Here, we report and interpret the healed laceration of a phacopine trilobite eye, revealing details about the genetic program that established the order of lens arrangement in a schizochroal eye. The first and superordinate level is the arrangement of the lenses in vertical and spiral-horizontal rows, which not only seems to be a forced arrangement as a result of eye growth, but which follows a genetically determined program since the order of the lenses is completely restored in one step, even after the visual surface has been destroyed completely. The size of the lenses, and thus their light-gathering capacity, is more flexible and interacts with the context within the pattern of the lenses. The origin of the lesion remains unresolved.

The Lower Palaeozoic successions of the Southern Uplands of Scotland are well known for graptolitic shales such as those of Dob’s Linn and Hartfell Score. Less well known are the Ordovician shelly fossils, predominately preserved in mudstones and conglomerates of the Sandbian Kirkcolm Formation at Kilbucho and Wallace’s Cast. Rare carbonate facies from the Wrae Limestone within the Tweeddale Member, Shinnel Formation preserve limestone olistoliths containing probable shelly faunas and conodonts from an otherwise unknown source. Trilobites, brachiopods and conodonts from the Southern Uplands have been the subject of some recent research, but other shelly faunas have received less attention. These include the mollusc faunas, consisting mainly of bivalves and gastropods. A review of the mollusc fauna supports faunal evidence from brachiopods that the Kirkcolm Formation was close to Pomeroy, Tyrone and sampled deeper water environments than was originally thought.

The Silurian inliers of the Pentland Hills contain abundant and diverse fossil assemblages and have interested geologists for more than 150 years. However, the faunas are very different from those found in the classic Anglo-Welsh area or the Spanish El Pintado Global Boundary Stratotype Section and Point (GSSP) for the Telychian Stage in peri-Gondwana. Initial geological exploration of the hills found few fossils, with little meaningful interest shown in the area until Dr Archibald Lamont, a controversial Scottish geologist, began researching the inliers. Lamont was the first to suggest that the rocks might be upper Llandovery rather than Wenlock, and went on to propose that their unique fossil assemblages warranted a new division being erected between the Llandovery and Wenlock series, which he named the ‘Pentlandian’. This new division was rejected by the international geological community. Euan Clarkson’s arrival in Edinburgh and his introduction to the Pentland Hills began what would be a lifetime’s fascination with the geology of the area. He instigated an extensive series of research projects and recruited researchers looking at the geology and a wide range of fossil groups, the most abundant of which is the Brachiopoda. The Telychian Wether Law Linn Formation in particular contains many shelly and graptolite faunas enabling correlation. The palaeocommunities identified suggest a deeper-water palaeoenvironment with finer-grained siliciclastic sediments set in a regressive marine sedimentary succession. Multivariate analyses show the mutual proximity of the Pentland associations and their distinctiveness from other Llandovery faunas. The Pentlandian is considered a regional term but the distinctive nature of the Pentlandian biotas, on a global scale, is confirmed and introduced here as the Pentlandian Biotic Complex.

A long-term research programme, spurred on first by Euan Clarkson, into controls upon the development of the middle Silurian trilobite Aulacopleura koninckii (Barrande 1846) has allowed insights into the processes by which exoskeletal segment size and shape were generatively controlled that are remarkable for a fossil of some 429 million years old. Competing hypotheses for the nature of the growth controls have been tested and resolved. These results provide palaeontological contributions to evolutionary developmental biology. Here the principal and widely scattered publications resulting from this effort are briefly summarised and reflected upon. This essay provides a contemporary, synoptic overview of our published literature on the development and life of this animal.

About three dozen specimens of the synziphosuran Limuloides limuloides (Woodward 1865) have been collected from Silurian strata in the Welsh Borderland since 1855, making it a rather rare component of the fauna. Most of these specimens are incomplete, mainly isolated prosomas. Here, a new specimen of the species is described from a single part (no counterpart). It is an articulated prosoma and opisthosoma, lacking a telson, and in apparently full relief. It comes from the lowermost Aston Mudstone Formation (Wenlock: Homerian, probably nassa zone), from a locality close to Aston Dingle near Bishop’s Castle, Shropshire, which is a new locality for L. limuloides, and the specimen is only the third known for this species in the Wenlock.