A new specimen of pterosaurian mandible from the Late Jurassic (Tithonian) Portland Limestone Group of southern England is described. Morphological considerations permit assignment to Pterodactyloidea. The elongate slender mandible and numerous closely spaced alveoli suggest it is a member of the Ctenochasmatidae. A faint median ridge on the occlusal surface between two grooves, converging into a median groove anteriorly, and the lack of a distinct premaxilla suggest the specimen is part of the symphysis of the mandible. This is the first documented record of a pterodactyloid from the Portland Group of England. (c) 2025 The Authors. Published by Elsevier Ltd on behalf of The Geologists' Association. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

An articulated and mostly complete skull roof of the enigmatic Early Jurassic chondrosteid fish, dagger Gyrosteus mirabilis Woodward ex Agassiz is described from the Whitby Mudstone Formation (Toarcian) of Whitby, Yorkshire. Known since the 1830s, isolated bones attributable to this taxon are frequently found along the Whitby coast, although articulated remains are rarely reported. The fragmentary nature of Gyrosteus mirabilis, the largest non-reptilian animal from the British Lower Jurassic, has led some researchers to propose it as a subjective synonym of dagger Chondrosteus Egerton ex Agassiz, from the Lower Lias of Dorset, and others to suggest synonymy with the similarly massive dagger Strongylosteus Jaekel from the Upper Lias (Toarcian) of Germany. Here, we compare the skull roof anatomies of dagger Gyrosteus mirabilis with dagger Chondrosteus acipenseroides and dagger Strongylosteus hindenburgi and present new criteria to differentiate between these taxa. We find the skull roofs of Chondrosteus and Strongylosteus to be vastly different with Gyrosteus representing something of an 'intermediate' morphology with closer affinities to Strongylosteus. The presence of a medial parietal and rostral bones is shared between Gyrosteus and Strongylosteus but these are absent in Chondrosteus. Our results support the taxonomic validity of both Gyrosteus mirabilis and Strongylosteus hindenburgi as monotypic genera distinct from Chondrosteus acipenseroides. (c) 2024 The Geologists' Association. Published by Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

A new genus and species of plagiaulacid multituberculate (Mammalia, Allotheria, Multituberculata) is described from the Cherty Freshwater Beds, Warbarrow Tout Member of the Lower Cretaceous Lulworth Formation of the Purbeck Group, Dorset, United Kingdom. The new taxon is represented by a complete, well preserved left dentary containing the incisor, p2-4, with alveoli for m1-2. This new specimen is the most complete multituberculate material yet recovered from the Purbeck Group. It is also the first mammal to be recovered from the so-called 'Flint Bed' (DB97). (c) 2025 The Author(s). Published by Elsevier Ltd on behalf of The Geologists' Association. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

An enigmatic partial trackway from the Aalenian to Bathonian (Middle Jurassic) Ravenscar Group of Whitby, North Yorkshire bears a striking resemblance to the pterosaur trace Pteraichinus. It also displays some similarities with the xiphosuran trackway Kouphichnium. The trackway is assigned to a new ichnogenus and ichnospecies Pseudopteraichnus whitbyensis. Using tetrapods as a comparator, Pseudopteraichnus is characterised by an elongate 'heel', a sub-triangular 'tarsus' and four unequal 'digits'. A possible fifth digit is located posterolaterally. The track maker is unknown. (c) 2024 The Geologists' Association. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

A new iguanodontian dinosaur, Comptonatus chasei gen. et sp. nov., is described from the Lower Cretaceous Wessex Formation of the Isle of Wight. These strata provide an important record of a critical time in the development of iguanodontian diversity. The specimen, which is described here for the first time, was found and excavated in 2013 and represents the most complete iguanodontian skeleton discovered in the Wealden Group for a century. A new taxon is diagnosed by several autapomorphies found in the neurocranium, teeth, coracoid and other parts of the body, together with a unique suite of characters. These include a dentary with a straight ventral border, and a markedly expanded prepubic blade. These features set it apart from the sympatric Mantellisaurus atherfieldensis, Brighstoneus simmondsi and Iguanodon cf. bernissartensis, increasing the known diversity of this clade in the Barremian-early Aptian of England. http://zoobank.org/urn:lsid:zoobank.org:pub:2F3125A5-BDEF-4835-8829-92104752A86F

The diets and feeding strategies of pterosaurs remain a poorly known although speculatively debated topic in vertebrate paleontology. Fossilized gut contents, which offer a crucial direct line of evidence to help decipher these elusive questions, are only known from a handful of pterosaur specimens in a few notable fossil Lagerst & auml;tten, such as the Solnhofen Limestone of Bavaria. Although extremely rare, pterosaurs can be exceptionally well preserved in the Lower Jurassic (Toarcian) Posidonia shale of Baden-W & uuml;rttemberg but, until now, none have been reported with identifiable gut contents. Here, we describe fossilized gut contents in two Posidonia Shale pterosaurs: Dorygnathus banthensis (Rhamphorhynchidae) and Campylognathoides zitteli (Campylognathoididae). Dorygnathus is shown to be piscivorous as indicated by the inclusion of the small teleost Leptolepis sp. preserved inside of the abdominal cavity. The gastrointestinal tract of Campylognathoides preserves associated accumulations of belemnoid hooklets referrable to Clarkeiteuthis conocauda and thereby demonstrating a teuthophagous diet. These findings represent the first convincing evidence for belemnoids contributing to the diet of a pterosaur and hint at a possible nocturnal hunting behavior for Campylognathoides. Previous hypotheses regarding dietary trophic partitioning based on differentiating skull anatomy in Posidonia Shale pterosaurs are supported.

Abstract Pterosaurs, the first vertebrates to evolve powered flight, dominated Mesozoic skies from the Late Triassic to the end Cretaceous, a span of around 154 Myr (∼220–66 Ma). They achieved their greatest diversity in the mid-Cretaceous and had become globally distributed, even occurring at high latitudes and in a wide range of habitats. The pterosaur record is dominated by occurrences in conservation Lagerstätten in just a handful of countries and a narrow range of temporal windows, most notably China, Germany and Brazil, and the Middle–Upper Jurassic and mid-Cretaceous. During the Cretaceous, two major pterosaur clades evolved edentulism, such that by the end of the Cretaceous, no toothed pterosaurs survived, having become extinct by the mid-Cenomanian. A distinctive aspect of pterosaur evolution during the mid-Cretaceous was the achievement of gigantic wingspans, perhaps in excess of 10 m, hyper-elongation of the neck vertebrae in Azhdarchidae, and the evolution of highly elaborate cranial crests. For many years, pterosaur diversity in the terminal stage of the Late Cretaceous was regarded as low, but discoveries in the last few decades have indicated pterosaur taxic diversity remained high until the end Maastrichtian, although morphological diversity may have been low. The demise of the Pterosauria at the K/Pg boundary was most likely due to the same causes as the coeval dinosaur extinction associated with the Chicxulub bolide impact and its environmental repercussions. Faunal replacement by avians is no longer considered a significant factor in pterosaur extinction.

The fossil remains of a pterodactyloid pterosaur from the Kimmeridge Clay Formation (Jurassic: Tithonian) of Abingdon, Oxfordshire, central England are identi fied as a partial left first wing finger phalanx. The elongation of the phalanx and distinctive morphology of the proximal articular region, in particular the square outline of the extensor tendon process, permit the specimen to be assigned to Ctenochasmatoidea. Although fragmentary, it is suf ficiently well preserved to determine accurately its dimensions when complete. Morphometric analysis reveals the specimen to represent one of the largest known examples of a Jurassic pterosaur, with an estimated wingspan of at least 3 m, and is one of the first pterodactyloids to be reported from the Jurassic of the United Kingdom. (c) 2024 The Geologists' Association. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

The Lower Cretaceous Wessex Formation of the Isle of Wight, UK, has produced a diverse dinosaurian fauna over the past 150 years. Hypsilophodontids are the most common small dinosaurs in the assemblage. Currently all hypsilophodontids are referred to Hypsilophodon foxii, originally described based on skulls and skeletons from the Hypsilophodon bed near Cowleaze Chine, in the uppermost Wessex Formation. We report a new hypsilophodontid, Vectidromeus insularis gen. et sp. nov., from exposures near Sudmoor Point, lying at the base of the exposed Wessex, similar to 150 m below the Hypsilophodon beds. Associated elements of the dorsal vertebrae, pelvis, hindlimbs, and tail are preserved. The specimen represents a juvenile, but differs from adult and juvenile Hypsilophodon foxii in the short and deep posterior iliac blade, short pubic peduncle, laterally exposed brevis fossa, rectangular ischia, and large fourth trochanter. Vectidromeus adds to the diversity of dinosaurs in the Wessex Formation. With other putative hypsilophodontids now assigned to other families, the Hypsilophodontidae currently comprises just Hypsilophodon and Vectidromeus, both from the Wessex Formation of the Isle of Wight.Hypsilophodontidae appear to be endemic to the Early Cretaceous of Europe. (c) 2023 Elsevier Ltd. All rights reserved.

Pterosaurs, iconic flying reptiles of the Mesozoic, walked on all fours. A new study has analysed their hand and foot anatomy and how it enabled the walking lifestyle that may have been the foundation of their attaining gigantic sizes.

An incomplete, but large hollow bone is identified as pterosaurian on account of its pneumatic nature, thin bone wall, palaeohistology and the characteristic surface texture of the peridermal bone. Despite being incomplete it is tentatively identified as a ?left ulna, and is remarkable for its size. Coming from the lower Middle Jurassic Lincolnshire Limestone Formation of Rutland, eastern England, this is the first record anywhere in the World of a Bajocian pterosaur, and probably the first pterosaur recorded from Rutland. It is most likely from Discites to Laeviuscula zones part of the lower Bajocian succession, and represents one of the largest Jurassic pterosaurs yet recorded, with a wingspan tentatively estimated at between 3.5 and 4.0 m. The taxonomic identity of the new specimen is uncertain, but it is likely allied to the Pterodactyloidea on account of its size, although presently it remains Pterosauria fam. et gen., et sp. indet. (c) 2024 The Geologists' Association. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Well-defined manus and pes print couple, likely from a trackway attributable to a sauropod dinosaur are revealed on a fallen block of Ravenscar Group sandstones in a cliff fall at Whitby, Yorkshire, England. The pes print displays four, possibly five toes and thus closely resembles that of the ichnogenera Brontopodus and Parabrontopodus. They are here referred to Brontopodus cf. pentadactylus Kim and Lockley, 2012. Impressions of a scaled integument are present around parts of the pes. The prints were likely made by a sauropod with a hip height of between 1.92 m and 2.83 m. Copyright (c) 2024 The Geologists' Association. All rights are reserved, including those for text and data miming, AI training, and similar technologies. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).

A partial caudal fin of a large-bodied asthenocormine pachycormiform (Pachycormiformes: Pachycormidae: Asthenocorminae) is described from the Upper Jurassic (lower Tithonian) Kimmeridge Clay Formation of Dorset, England. The specimen comprises associated fin rays, basal fulcra, ‘epurals’ and paired pre-caudal scutes, the combination and morphology of which is consistent with the large (2–3 m TL) edentulous, supposedly ‘suspension-feeding’ asthenocormine, Asthenocormus titanius (Wagner), presently known only from the Upper Jurassic plattenkalks of Bavaria, Germany. Asthenocormus has previously been documented in the literature as being present in the Middle and Upper Jurassic of England, however all of these specimens have been misattributed or since referred to different genera. However, the specimen from the Kimmeridge Clay Formation is here referred with confidence to Asthenocormus. Morphological variation in the pre-caudal dorsal scute of the new specimen compared to the Bavarian material suggest that the Kimmeridge Clay specimen likely represents a new species of Asthenocormus, although it is currently too poorly represented to diagnose, and hence we refer the specimen to Asthenocormus cf. titanius. The new specimen represents the first true record of Asthenocormus from the UK, thereby extending its known palaeobiogeographic distribution and further demonstrating faunal similarities between fish assemblage from the Kimmeridge Clay Formation of Dorset and the Solnhofen-type plattenkalks of southern Germany. Additional comments are also made on the hidden diversity of pachycormid fishes in the Kimmeridge Clay Formation.

Although diverse, disparate, widespread, and long-lived, our understanding of pterosaurs is heavily biased by specimens from Konservat-Lagerstätten. Here we consider the pterosaur assemblage of the mid-Cretaceous Kem Kem Group of southeast Morocco and compare its taphonomy to other Cretaceous pterosaur-bearing assemblages. The Kem Kem Group pterosaur bones are usually fragmentary and isolated but preserved three-dimensionally, with excellent preservation of macroscopic internal structures and bone histology at ultrastructural levels. The pterosaur assemblage is dominated by azhdarchoid jaw fragments, all anterior of the nasoantorbital fenestra and divergence of the mandibular rami. Post-cranial elements are much rarer with a striking lack of syncarpals, despite being some of the most robust elements of the skeleton. Comparisons with similar deposits in the United Kingdom, Uzbekistan and USA suggest that this relative skeletal abundance is unusual for pterosaur assemblages. The overabundance of jaw material in the Kem Kem Group is likely the result of a combination of factors including the inherent mechanical strength of the jaws, selective predation and scavenging and transportation/hydrodynamic sorting of some elements. The Kem Kem Group should be considered a Konzentrat-Lagerstätte due to the high abundance of vertebrate material. Despite the fragmentary nature of the material, it has excellent preservation of internal structures at macroscopic and microscopic scales. The Kem Kem Group pterosaur assemblage is among the most species diverse known, but taphonomic processes and biases likely obscure its true diversity.

A new long-legged, spatula-beaked, filter-feeding pterodactyloid pterosaur from Upper Jurassic plattenkalk limestones at Wattendorf, Bavaria, Southern Germany, is remarkable for its completeness, unusual dentition and hints of the preservation of soft tissues, including wing membranes. The fully articulated specimen displays both jaws each side with over one hundred sub-parallel-sided teeth with a small, slightly hooked expansion at the crown tip. There are at least 480 teeth in total. The tip of the rostrum widens to a spatula-like, laterally concave structure with teeth only along its lateral margins. The straight anterior margin is devoid of teeth allowing plankton-rich water to stream in, while the teeth interdigitate forming a fine mesh trap. A slightly up swept rostrum assisted filtering by probable pulsating movements of the long neck, while wading or swimming through shallow water.

A single dorsal bony scute from the uppermost Cretaceous (Maastrichtian) marine phosphatites of central Morocco is identified as an acipenserid fish (sturgeon). The new specimen represents the first occurrence of an acipenseriform fish on the continent of Africa.

A single tooth identified as cf. Spinosaurus sp. from the Ifezouane Formation of the Kem Kem Group of eastern Morocco is noteworthy for a series of extensive palaeopathologies. These include an enhanced lingual curvature to the crown and the development of three deep grooves extending from at least the crown root junction to the apex of the crown. An attenuated carina is present but this does not extend to the crown tip, and neither does it start at the crown base. A wear facet is also present at the tip. This is the first report of external dental pathologies in the tooth of a spinosaurine spinosaurid.

Ganoine-scaled fishes belonging to the superfamily Lepisosteoidea, more commonly known as gars, are an ancient lineage with origins in the Mesozoic, first appearing in the Kimmeridgian, Late Jurassic. The Mesozoic gar fossil record is patchy, mostly consisting of disarticulated remains, with only a few partially or mostly complete specimens being extremely rare. Extant gars typically occur in freshwater and brackish environments, with rare observations of a few species frequenting saline waters although little is known of their marine ancestors. Here we describe a new genus and species, Grandemarinus gherisensis gen. et sp. nov., an unusually short-snouted gar from the Upper Cretaceous (Turonian) Akrabou Formation of Morocco. The short-snouted cranial bauplan is superficially convergent with the Eocene freshwater genera Cuneatus and Masillosteus, although a phylogenetic analysis resolves the new gar as the sister taxon to the Lepisosteini (Oniichthys, Lepisosteus, Atractosteus), falling outside of Masillosteinae (Masillosteus, Cuneatus). Gars likely originated as fully marine fishes during the Late Jurassic, and during Early Cretaceous times successfully invaded freshwater ecosystems. The new gar described here is likely a late surviving member of this early marine lineage. The new lepisosteiform is the first complete gar described from a Cretaceous marine deposit; representing a vital clue to help decipher the early evolution and ecology of Lepisosteidae. The taphonomy of the specimen is discussed within the context of a fully marine carbonate Konservat Lagerstaeurotte. & COPY; 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

The pterosaur assemblage of the mid-Cretaceous Kem Kem Group of Morocco is reviewed. This analysis examines their taxonomy, palaeoecology and palaeobiology with comments on taphonomy. New material permits the rediagnosis of the azhdarchoids Alanqa saharica and Afrotapejara zouhrii . Several specimens are reported that do not fit within the paradigms of previously named taxa. They represent three distinct jaw morphotypes, but are not assigned to new taxa here. The assemblage is highly diverse, including four tooth-bearing taxa assigned to Ornithocheiridae and five named taxa and three additional morphotypes assigned to Azhdarchoidea. The Kem Kem Group assemblage is the most diverse for any pterosaur-bearing fluvial deposit and one of the most diverse of any pterosaur assemblage. The assemblage is heavily biased in terms of preservation with an as yet unexplained high abundance of jaw fragments. We highlight the importance of fragmentary material in pterosaur studies.

An isolated jaw fragment from the Late Cretaceous (Cenomanian) Cambridge Greensand Member of the West Melbury Marly Chalk Formation previously identified as a cestraciontid shark fin spine is referred to the pterosaur clade Azhdarchoidea on account of its lateral and occlusal foramina and edentuly. The specimen differs from the azhdarchoid Ornithostoma sedgwicki from the same deposit in having flat lateral surfaces and an acute dorsal/ventral apex. The specimen is similar in overall morphology to CAMSM B40085 from the same horizon and probably represents the corresponding jaw but from a different individual. Likely these specimens represent a new taxon but are considered too fragmentary to diagnose at present. A remarkably similar and distinctive morphology is found in unnamed pterosaur jaws from the Kem Kem Group (?Albian-Cenomanian) of Morocco, supporting the idea of faunal similarity between these two distant localities.