The frequency of growth increments in the tube wall of the Mesozoic and Cenozoic serpulids is in the range of modern species (i.e. 7–37 growth lines per 50 μm). The growth increments of serpulids do not show correlation with the water temperature and presumably cold water and warm water serpulid species are growing on average with similar speed in terms of number of growth lines per 50 μm. The large serpulid species have usually significantly larger growth increments than smaller species and presumably also grew faster than smaller species. The species with denser skeletons have lower growth rates than species with more porous skeletons. It is possible that serpulids do not have to calcify faster to produce thicker growth increments with lower density.

Horseshoe crabs (Xiphosura) have a long evolutionary history starting in the Ordovician, but they have rarely been reported from the Netherlands. We report on the first Triassic horseshoe crab from the Netherlands identifiable to the species level, a specimen of the limulid Limulitella bronnii. We provide the first diagnosis for this species and refigure the holotype. The new specimen was found in the Middle Triassic (Anisian) Muschelkalk sediments of the Vossenveld Formation, in the Illyrian part of the stratigraphic profile of the Winterswijk quarry complex. The Winterswijk specimen represents the youngest occurrence of L. bronnii. The inferred non-marine habitat of this horseshoe crab species elsewhere in conjunction with occurrences of plant and insect remains within the same layer at Winterswijk suggest the specimen herein most probably did not live in marine conditions either. This species has previously been found in non-marine sediments in France and Germany, expanding its geographic range northward. Several faunal elements from Winterswijk including L. bronnii show resemblance to the roughly co-eval non-marine components of the Anisian Grès à Voltzia Formation in NE France, suggesting a paleobiogeographic connection between these regions in Western Europe.

The Mesozoic is considered as the ‘golden age’ for the diversification of Neuroptera (lacewings), and many unusual lacewing larvae have been discovered in Cretaceous amber. However, little is known about their early evolution because of the rarity of fossils. Herein, we describe a new genus and species, Kuafupolydentes hui gen. et sp. nov., one of the biggest lacewing larvae from the Cretaceous known so far, based on a well-preserved specimen from mid-Cretaceous Kachin amber (99 Ma). The new larva is characterized by its large size, each stylet with eight short and blunt teeth, robust and long antennae, and long and robust legs with continuous tarsus and tibia and enlarged claws. It can be considered as an early representative of the antlion clade, Myrmeleontiformia. We suggest that the new larva is also an ambush predator like extant antlions, but it might have used a different strategy to kill large prey. Some of the morphological characters of K. hui are unknown in any extant lacewings and suggest a greater morphological disparity of Neuroptera during the Cretaceous.

An integrated approach involving Sr–Nd isotope, trace and rare earth element analyses tracks multiple sources of the Mesozoic sediments of the Kutch Basin at the western continental margin of India. High (87Sr/86Sr)t (ratio at time of deposition), negative εNd and high concentrations of large-ion lithophile elements (LILEs) indicate the upper continental source. Ratios of Nb/Ta and Zr/Hf suggest sedimentary and felsic igneous sources of sediments. The moderate to high concentration of La, Th and Sc, light rare earth elements (LREE-) enrichment, weak negative Eu anomalies and the relationship between εNd(0) and Th/Sc indicate the dominantly felsic composition of source rocks. However, low contents of Th, low values of (87Sr/86Sr)t and depleted mantle model age TDM < 1600 Ma indicate input from a younger mafic source. Increasing concentrations of Zr, Hf and Nd isotopes and a gradual increase in mean TDM from the older to the younger formations indicate erosional unroofing at the source terrain. The increasing (87Sr/86Sr)t through time relates to increased weathering of the source rock. The overwhelmingly southwesterly palaeocurrent direction of current-generated sedimentary structures, and the mean TDM ages trace suggest source areas of the Kutch Basin to Precambrian rocks in the north and NE of this basin. The TDM ages highlight the dominance of late Palaeoproterozoic source rocks. Nd isotope composition indicates that Proterozoic rocks of Marwar Supergroup and Erinpura Granite, in particular, served as main sediment contributors for the Mesozoic sediments in Kutch. We therefore conclude that the Mesozoic sediments in the Kutch Basin are predominantly of late Palaeoproterozoic age with lesser inputs from rocks of early Mesoproterozoic and early Palaeoproterozoic age.

The Toarcian Oceanic Anoxic Event (T-OAE, c. 182 Ma) represents a major perturbation of the carbon cycle marked by widespread black shale deposition. Consequently, the onset of the T-OAE has been linked to the combined effects of global warming, high productivity, basin restriction and salinity stratification. However, the processes that led to termination of the event remain elusive. Here, we present palynological data from Arctic Siberia (Russia), the Viking Corridor (offshore Norway) and the Yorkshire Coast (UK), all spanning the upper Pliensbachian – upper Toarcian stages. Rather than a ‘dinoflagellate cyst black-out’, as recorded in T-OAE strata of NW Europe, both the Arctic and Viking Corridor records show high abundance and dinoflagellate diversity throughout the T-OAE interval as calibrated by C-isotope records. Significantly, in the Arctic Sea and Viking Corridor, numerous species of the Parvocysta and Phallocysta suites make their first appearance in the lower Toarcian Falciferum Zone much earlier than in Europe, where these key dinoflagellate species appeared suddenly during the Bifrons Zone. Our results indicate migrations of Arctic dinoflagellate species, driven by relative sea-level rise in the Viking Corridor and the establishment of a S-directed circulation from the Arctic Sea into the Tethys Ocean. The results support oceanographic models, but are at odds with some interpretations based on geochemical proxies. The migration of Arctic dinoflagellate species coincides with the end of the T-OAE and marks the arrival of oxygenated, low-salinity Arctic waters, triggering a regime change from persistent euxinia to more dynamic oxygen conditions.

The Iberia–Newfoundland continental margin is one of the most-studied conjugate margins in the world. However, many unknowns remain regarding the nature of rifting preceding its break-up. We analyse a large dataset of tectonic subsidence curves, created from publicly available well data, to show spatial and temporal trends of rifting in the proximal domains of the margin. We develop a novel methodology of bulk averaging tectonic subsidence curves that can be applied on any conjugate margin with a similar spread of well data. The method does not rely on the existence of conjugate, deep seismic profiles and, specifically, attempts to forego the risk of quantitative bias derived from localized anomalies and uncertain stratigraphic dating and correlation. Results for the Iberia–Newfoundland margin show that active rift-driven tectonic subsidence occurred in the Central segment of the conjugate margin from c. 227 Ma (early Norian) to c. 152.1 Ma (early Tithonian), in the southern segment from c. 208.5 Ma (early Rhaetian) to c. 152.1 Ma (early Tithonian) and in the northern segment from c. 201.3 Ma (early Hettangian) to c. 132.9 Ma (early Hauterivian). This indicates that rifting in the stretching phase of the proximal domain of the Iberia–Newfoundland margin does not mirror hyperextended domain rifting trends (south to north) that ultimately led to break-up. The insights into broad-scale three-dimensional spatial and temporal trends, produced using the novel methodology presented in this paper, provide added value for interpretation of the development of passive margins, and new constraints for modelling of the formation of conjugate margins.

Residual clays that developed on Permian and Carboniferous glass-rich silicic volcanic rocks (pitchstones, ignimbrites) at the Seilitz and Kemmlitz kaolin deposits, Saxony, Eastern Germany, contain locally abundant lath-shaped illite-rich illite-smectite mixed-layer minerals (I-S). Analyses by XRD and TEM-AES reveal a large illite percentage (>∼90%) and R3 ordering in I-S from Seilitz (>∼90%) and smaller illite percentage (∼70%) and R1 ordering in I-S from Kemmlitz. The clays never suffered a deep burial and there is no geological, petrographic or fluid inclusion evidence for aeolian input or hydrothermal origin of I-S at either deposit. The I-S formed exclusively at the expense of volcanic glass and not from K-feldspar. Residual quartz phenocrysts in the clays still preserve primary glassy silicate melt inclusions and lack secondary aqueous fluid inclusion trails. The dD and δ18O values of kaolinite and I-S are suggestive of low formation temperatures (<40ºC). Rb-Sr and K-Ar dating of I-S-bearing clay separates yield Lower Cretaceous ages at Seilitz and indicates the presence of excess or inherited 40Ar in illite-rich I-S. In contrast, Triassic to Jurassic Rb-Sr ages are obtained for I-S from the Kemmlitz kaolin deposit.

The deformation of the Solonker Belt and nearby regions is helpful for understanding the tectonic evolution of the Central Asian Orogenic Belt. This study carried out structural analysis in the Mandula and Ganqi areas of western Inner Mongolia, including the Solonker Belt, the Southern Orogenic Belt and the northern Yinshan Belt (Langshan range). Our results reveal that the Solonker Belt, the Southern Orogenic Belt and the northern Yinshan Belt underwent two stages (D1 and D2) of deformation during the Mesozoic period. The D1 stage produced the NNE-directed thrusts and asymmetric folds, indicating a NNE–SSW contraction. The northern Yinshan Belt, the Southern Orogenic Belt and the Solonker Belt formed as a series of NNE-verging tectonic nappes. The D2 stage developed the NE-trending folds and the SE- or NW-directed thrusts that cross-cut the D1 structures. The two events of nearly orthogonal or oblique shortening gave rise to the superimposed structures (e.g. fold interference patterns). The quartz veins that filled the fractures of the D1 deformation contain zircons of Middle Triassic U–Pb ages. The new dating data, along with the regional sedimentary hiatus, led us to infer that the D1 stage of deformation occurred in Middle Triassic time and the D2 stage occurred in Late Jurassic time. We consider that the D1 stage of deformation resulted from a convergent event, which might be related to the closure of the Palaeo-Asian Ocean or limited, narrow ocean basins; and the D2 stage of deformation was the far-field result of subduction of the Palaeo-Pacific Ocean and the closure of the Mongol-Okhotsk Ocean.

A comprehensive analysis of early dinosaur relationships raised the possibility that the group may have originated in Laurasia (Northern Hemisphere), rather than Gondwana (Southern Hemisphere) as often thought. However, that study focused solely on morphology and phylogenetic relationships and did not quantitatively evaluate this issue. Here, we investigate dinosaur origins using a novel Bayesian framework uniting tip-dated phylogenetics with dynamic, time-sliced biogeographic methods, which explicitly account for the age and locality of fossils and the changing interconnections of areas through time due to tectonic and eustatic change. Our analysis finds strong support for a Gondwanan origin of Dinosauria, with 99 % probability for South America (83 % for southern South America). Parsimony analysis gives concordant results. Inclusion of time-sliced biogeographic information affects ancestral state reconstructions (e.g., high connectivity between two regions increases uncertainty over which is the ancestral area) and influences tree topology (disfavouring uniting fossil taxa from localities that were widely separated during the relevant time slice). Our approach directly integrates plate tectonics with phylogenetics and divergence dating, and in doing so reaffirms southern South America as the most likely area for the geographic origin of Dinosauria.

Remains of a coelacanth specimen are described from Rhaetian deposits of the Var Department, southeastern France. They comprise the lower part of a branchial apparatus associated with a left lower jaw and a basisphenoid. Osteological features of the angular and basisphenoid and the teeth ornamentation allow the inclusion of the specimen in the mawsoniid family, genus and species indeterminate. Mawsoniids are known in freshwater environments from the Triassic of North America and from the Cretaceous of Western Gondwana and Europe, as well as from Late Jurassic marine environments from Europe. The new discovery here reported represents the first coelacanth from the marine Triassic of France and improves the understanding of the palaeobiogeography of the Mawsoniidae.

The North China Craton (NCC) is one of the classic examples of decratonization through extensive lithospheric destruction during Mesozoic time. Among the various pulses of magmatism associated with cratonic erosion are the rare mafic intrusions in the Yanshan Belt. Here we investigate the Shangzhuang layered intrusion belonging to this suite, which is characterized by compositional layering with troctolite, noritic gabbro and gabbro/gabbroic anorthosite/gabbrodiorite from the bottom to top. The different lithologies of this intrusion exhibit close field relationships, similar chemical patterns and overall identical Lu–Hf isotopes indicating a co-magmatic nature. The fine-grained gabbros occurring near the margin of the intrusion display U–Pb ages similar to those of the other rocks and are considered to represent the composition of the parent magma, characterized by Fe, Mg and Ti enrichment. The magma was sourced from low-degree partial melting of spinel lherzolite sub-continental lithospheric mantle, which had been enriched by crust–mantle interaction and metasomatic fluids derived from the Mongolian oceanic slab subduction beneath the NCC during Late Palaeozoic time. In addition, limited asthenospheric or deeper-mantle materials were also locally mixed with the enriched mantle as the final source component. Our zircon U–Pb data constrain the emplacement age of this intrusion as c. 128–123 Ma in Early Cretaceous time, and correlates with the regional extensional tectonics between c. 135 and 115 Ma in the eastern and central NCC. Mantle upwelling associated with this event resulted in the thermal and chemical erosion of the lithospheric mantle, and emplacement of the parent magma of this layered intrusion.

The Triassic–Jurassic rift-valley stage of Tethyan rifting in the Western-Central Mediterranean area is characterized by a development of a puzzle of plates and microplates with the deposition of continental redbeds (in the internal domains of the Gibraltar Arc and Calabria–Peloritani Arc) that can be considered a regional lithosome. This paper aims to reconstruct the chemical weathering conditions of the Triassic–Jurassic boundary in the Western-Central Mediterranean area using the geochemical and mineralogical composition of continental redbed mudrocks of Mesozoic age. The mudrocks from the Calabria–Peloritani Arc show higher values of weathering (mobility) indices (αMg=(Al/Mg)sed/(Al/Mg)UCC; αK=(Th/K)sed/(Th/K)UCC; αBa=(Th/Ba)sed/(Th/Ba)UCC) than the Gibraltar Arc samples. Furthermore, the CIA (Chemical Index of Alteration) and MIA (Mineralogical Index of Alteration) values and the ‘Rb-type indices’ (e.g. Rb/Sr and Rb/K ratios) are higher for the Calabria–Peloritani Arc mudrocks than the Gibraltar Arc samples. All these geochemical proxies closely resemble each other and show similar variations suggesting climatic changes towards humid conditions through the Uppermost Triassic to Lowermost Jurassic that favoured chemical weathering conditions. This period is probably characterized by seasonal climate alternations corresponding to an increase in palaeoclimatic humidity. The mineralogical compositions of the Mesozoic mudrocks further confirm these indications as shown by a higher abundance of kaolinite, related to warm–humid conditions, in the Calabria–Peloritani Arc mudrocks than in those of the Gibraltar Arc.

The genus Orthobittacus was established by Willmann (1989) and is characterised by a long Sc vein and the unusually developed medial sector for the Bittacidae. Four Jurassic species have been described in this genus to date: O. abshiricus (Martynova, 1951) from Kirgizia; O.desacuminatus (Bode, 1953) from Braunschweig (Germany); O. polymitus Novokshonov, 1996 from Karatau (Kazakhstan); and O. maculosus Liu, Shih, Bashkuev & Ren, 2016 from the Jiulongshan Formation of Daohugou (China). The fifth congeneric and second species from China, O. suni sp. nov., is described herein. The importance of the genus Orthobittacus for the phylogeny of Bittacidae, as the most plesiomorphic genus, is discussed.

Twelve specimens of early Toarcian Mecoptera and Diptera from the vicinity of Wolfsburg were investigated for the present study. The material was found during house building activities in the 1980s at the locality Große Kley in Mörse, an urban district of the city of Wolfsburg, Lower Saxony, Germany. The specimens were found in calcareous nodules of the Harpoceras falciferum Zone that occur within the Liassic black shales (Posidonia shale). Six specimens of Mecoptera, five belonging to the family Orthophlebiidae and one belonging to the Bittacidae, and six representatives of the following Diptera families were identified: Ptychopteridae, Limoniidae, Anisopodidae and the superfamily Mycetophiloidea. The fossil fauna of Wolfsburg is similar to that of other early Toarcian sites in Germany, described by Handlirsch (1906, 1939), Bode (1905, 1953) and Ansorge (1996) from Braunschweig, Dobbertin and Grimmen. Two new species are described, Mesorhyphusulrichi sp. nov. (Anisopodidae) and Archipleciomima germanica sp. nov. (Mycetophiloidea).

Since the beginning of the development of the North German Basin in Stephanien to Early Rotliegend times, rifting played a major role. Nearly all structures in NW-Germany and the German North Sea - (more than 800) - salt diapirs, grabens, inverted grabens and inversion structures - are genetically related to rifting. Today, the rifting periods are well dated. We find signs of dilatation at all times except from the Late Aptian to the end of the Turonian. To the contrary, the period of the Coniacian and Santonian, lasting only five million years was a time of compression, transpression, crustal shortening and inversion. Rifting activities decreased notably after inversion in Late Cretaceous times. Tertiary movements concentrated on a limited number of major, long existing lineaments. Seismically today NW-Germany and the German North Sea sector is one of the quietest regions in Central Europe.

To date, igneous rocks, either intrusive or extrusive, have been encountered in the Palaeozoic-Mesozoic sedimentary series of the Netherlands in some 65 exploration and production wells. Following 17 new isotopic K/Ar age determinations of the recovered rock material (amounting to a total of 28 isotopic ages from 21 different wells), analysis of the stratigraphic distribution of the penetrated igneous rock bodies showed that the timing of their emplacement was importantly controlled by orogenic phases involving intra-plate wrench and rift tectonics. Magmatism coincided with the Acadian (Late Devonian), Sudetian (early Late Carboniferous), Saalian (Early Permian), Early Kimmerian (late Late Triassic), Mid-Kimmerian (Late Jurassic), Late Kimmerian (earliest Cretaceous) and Austrian (latest Early Cretaceous) tectonic phases. This synchroneity presumably reflects (broadly) coeval structural reorganizations of respectively the Baltica/Fennoscandinavia-Laurentia/Greenland, Laurussia-Gondwana, African-Eurasia and Greenland/Rockall-Eurasia plate assemblies. Through their concomitant changes of the intra-plate tectonic stress regime, inter-plate motions induced intra-plate tectonism and magmatism. These plate-tectonics related events determined the tectonomagmatic history of the Dutch realm by inducing the formation of localized centres, as well as isolated spot occurrences, of igneous activity. Some of these centres were active at (about) the same time. At a number of centres igneous activity re-occurred after a long period of time.

Central Mexico was subject to active tectonics related to subduction processes while it occupied a position in western equatorial Pangea during early Mesozoic time. The subduction of the palaeo-Pacific plate along the western North American and South American active continental margins produced volcanic arc successions which were subsequently rifted and re-incorporated to the continental margin. In this context, the fringing arcs are important in unravelling the continental accretionary record. Using petrographic analysis, detrital zircon geochronology and structural geology, this paper demonstrates that the Guerrero Arc (Guerrero Terrane) formed on top of a felsic volcaniclastic unit (Middle Jurassic La Pimienta Formation) and siliciclastic strata (Upper Triassic Zacatecas Formation and Arteaga Complex) of continental Mexican provenance, deposited across the continental margin and oceanic substrate. This assemblage was rifted away from continental Mexico to form an intervening oceanic assemblage (Upper Jurassic – Lower Cretaceous Las Pilas Volcanosedimentary Complex of the Arperos Basin), then accreted back more or less at the same place, all above the same east-dipping subduction zone. The accretion of the Guerrero Arc to the Mexican continental mainland (Sierra Madre Terrane) caused the deposition of a siliciclastic unit (La Escondida Phyllite), which recycled detritus from the volcaniclastic and siliciclastic underlying strata.

We amend the taxonomy and provide new anatomical information on the hadrosaurid dinosaur Saurolophus morrisi (upper Maastrichtian Moreno Formation, central California, USA) derived from full preparation of the referred skull roof. The cranial morphology of this species is distinct enough to justify the new combination Augustynolophus morrisi gen. nov. The morphology of the nasals and surrounding cranial bones indicates that A. morrisi sported a solid nasal crest ending in an elongate triangular plate that extended above the skull roof. Autapomorphies include a crescentic base of the frontal caudodorsal process and extension of the process caudal to the frontal ‘dome’; distal end of nasal crest with knob-like process inflected rostrally; circumnarial depression lightly incised and weakly emarginated, adjacent to caudolateral margin of nasal and occupying two-thirds the width of lateral surface of distal region of crest; and caudal surface of distal nasal crest subrectangular. We formally establish the new tribe Saurolophini consisting of Prosaurolophus, Augustynolophus and Saurolophus. Saurolophin synapomorphies include a premaxilla with broad arcuate contour of rostrolateral region of thin everted oral margin and flat and steeply inclined occlusal surface of dentary dental battery, among other characters. Saurolophin crests evolved towards increasing caudodorsal length, along with caudal extension of the circumnarial fossa and involvement into the crest of adjacent facial elements. Augustynolophus is the second described genus of North American late Maastrichtian hadrosaurids. Its recognition implies a greater diversity among late Maastrichtian dinosaur faunas than previously recognized and is congruent with hypotheses of endemism and/or provinciality during Late Cretaceous time.

The morphologies of the hyobranchial apparatus in early tetrapods are reviewed, based primarily on first-hand examination and supplemented by published descriptions. The basic arrangement of the “aquatic” hyobranchium, with four pairs of branchial arches and internal gills, was conserved to a remarkable degree across the fish–to–tetrapod transition and was retained in further evolution in adults of several tetrapod lineages. Thus, a fish-like hyobranchium in basal tetrapods does not necessarily represent a larval or paedomorphic character, respectively, as was often suggested in analogy to extant salamanders. Rather, it represents the plesiomorphic state of the adult hyobranchium in tetrapods. The changes in the hyobranchium during the fish–to–tetrapod transition include the reduction of the number of skeletal elements and their morphological simplification. In all three presently discussed scenarios of lissamphibian origin, the temnospondyl, lepospondyl and diphyly hypotheses, the internal gills were reduced independently within temnospondyls and on the amniote stem below seymouriamorphs. Evidence of remodelling into a true “terrestrial” hyobranchium, with reduction of the posterior branchial arches and modification to support terrestrial tongue feeding, is scarce in early tetrapods. It evolved within temnospondyls in zatracheids, amphibamids and lissamphibians, as well as once or several times in early amniotes or in their immediate stem-forms.