A detailed account of the morphology and ontogeny of the late Middle Cambrian crustacean †Henningsmoenicaris scutula is presented. Ten successive ontogenetic stages could be recognised in the material collected from various localities in Sweden. Morphogenetic changes include the development of a pair of stalked lateral eyes and the increase in the number and size of appendages and their setal armature. Notably, early stages lack ‘proximal endites’ on all post-antennular appendages; such a spine-bearing endite has previously been thought to appear simultaneously on these limbs. In †H. scutula a single functional endite appears on the third limb in an advanced stage; an additional endite appears on the second limb and, subsequently, further endites appear on more posterior limbs. Furthermore, a single specimen of †Sandtorpia vestrogothiensis gen. et sp. nov. is described. Based on this new information and data of other ‘Orsten’ taxa, particularly those assigned already to the early evolutionary lineage of Crustacea, a small-scale computer-based phylogenetic analysis was performed. This resolved the basal branchings of Crustacea s. l. as follows: †Oelandocarididae (=†Oelandocaris oelandica+†H. scutula+†S. vestrogothiensis)+(†Cambropachycopidae (=†Goticaris longispinosa+†Cambropachycope clarksoni)+ (†Martinssonia elongata+Labrophora (=†Phosphatocopina+Eucrustacea))). Plotting ontogenetic data on the phylogram and comparing the ground pattern at every node led to the detection of three peramorphic heterochronic events in the evolutionary lineage towards Eucrustacea.

Among most of the geologists who had of late years been engaged in investigating the structure of the North-West Highlands, and especially among those who did not concur in Murchison's explanation of the phenomena exhibited there, it was a growing belief that great overthrusts had been largely instrumental in producing the remarkable stratigraphical relations of the rock masses of that region. After a most careful detailed examination of the ground by the Geological Survey, the existence and importance of such thrusts was not only placed beyond a doubt, but a variety of additional remarkable structures were discovered, which open up new fields of investigation to the physical geologist.

Several mesosocopic structures are consistent with mechanical accumulation of crystals and movement of melt in granite magmas, as well as compaction and shear of crystal-melt aggregates, concentrations of microgranitoid enclaves indented by megacrysts, and concentrations of crystals of the same mineral with different crystallisation histories. Evidence for crystal and enclave accumulation is shown clearly in mafic and silicic layered intrusions (MASLI-type granite plutons), for example, the Kameruka Granodiorite, Bega Batholith, south-eastern Australia.

Crystal accumulations with interstitial liquid may become mobile in a magma chamber, owing to instabilities in the host magma caused by seismic and replenishment events or thermal and buoyancy variations. This remobilised material may intrude other parts of the chamber, as well as earlier-formed cumulates and even wall-rocks, as dykes, tubes, troughs and pipes. Marked concentrations of accessory and mafic minerals may also develop in these structures. Interstitial melt may also be extracted from accumulated aggregates, intruding and disrupting the aggregates. Spectacular examples of these various structures are preserved in the Tuolumne Batholith, California. Detailed mechanisms for the formation of many of the structures are not well understood, though the formation of cumulates in vertical layers suggests that sorting and filter pressing during flow and resulting strain of crystal mushes may play important roles.

Several mesosocopic structures are consistent with mechanical accumulation of crystals and movement of melt in granite magmas, as well as compaction and shear of crystal-melt aggregates, concentrations of microgranitoid enclaves indented by megacrysts, and concentrations of crystals of the same mineral with different crystallisation histories. Evidence for crystal and enclave accumulation is shown clearly in mafic and silicic layered intrusions (MASLI-type granite plutons), for example, the Kameruka Granodiorite, Bega Batholith, south-eastern Australia.

Crystal accumulations with interstitial liquid may become mobile in a magma chamber, owing to instabilities in the host magma caused by seismic and replenishment events or thermal and buoyancy variations. This remobilised material may intrude other parts of the chamber, as well as earlier-formed cumulates and even wall-rocks, as dykes, tubes, troughs and pipes. Marked concentrations of accessory and mafic minerals may also develop in these structures. Interstitial melt may also be extracted from accumulated aggregates, intruding and disrupting the aggregates. Spectacular examples of these various structures are preserved in the Tuolumne Batholith, California. Detailed mechanisms for the formation of many of the structures are not well understood, though the formation of cumulates in vertical layers suggests that sorting and filter pressing during flow and resulting strain of crystal mushes may play important roles.

Glaucophane-Schists and eclogite are associated with ultrabasic rocks, basic intrusions and Ordovician spilitic lavas at Knockormal in the Girvan-Ballantrae complex, South Ayrshire. Detailed mineralogical and chemical data are presented which indicate that the various glaucophane and blue-amphibole rocks have been derived from spilitic lavas. In addition to glaucophane a blue-amphibole related to crossite is also described. While there is no evidence for an introduction of soda, the deformation attending the glaucophanitic metamorphism was accompanied by chemical changes which appear to have occurred at high water-vapour pressures. There is no evidence of any relationship between the eclogite and adjacent glaucophane-rocks. The eclogite, which is highly aluminous, is interbanded with wehrlite, pyroxenite and serpentinite, and represents a particular phase in the crystallization of these ultrabasic rocks.

The rise of archosaurs during the Triassic and Early Jurassic has been treated as a classic example of an evolutionary radiation in the fossil record. This paper reviews published studies and provides new data on archosaur lineage origination, diversity and lineage evolution, morphological disparity, rates of morphological character change, and faunal abundance during the Triassic–Early Jurassic. The fundamental archosaur lineages originated early in the Triassic, in concert with the highest rates of character change. Disparity and diversity peaked later, during the Norian, but the most significant increase in disparity occurred before maximum diversity. Archosaurs were rare components of Early–Middle Triassic faunas, but were more abundant in the Late Triassic and pre-eminent globally by the Early Jurassic. The archosaur radiation was a drawn-out event and major components such as diversity and abundance were discordant from each other. Crurotarsans (crocodile-line archosaurs) were more disparate, diverse, and abundant than avemetatarsalians (bird-line archosaurs, including dinosaurs) during the Late Triassic, but these roles were reversed in the Early Jurassic. There is no strong evidence that dinosaurs outcompeted or gradually eclipsed crurotarsans during the Late Triassic. Instead, crurotarsan diversity decreased precipitously by the end-Triassic extinction, which helped usher in the age of dinosaurian dominance.

The state of Texas has one of the greatest records of pterosaurs in the world, surpassing all other US states and most countries in the number of occurrences. Uniquely, this record extends over the entire 150+ million history of the Pterosauria. A review of this pterosaur record confirms at least 30 pterosaurs known from 13 occurrences, including five valid species. The holotypes of two of these species have been described before and are diagnosed and erected here as the new species Radiodactylus langstoni, gen. et sp. nov., named in honour of Dr. Wann Langston Jr, the father of Texas pterosaurology, and Alamodactylus byrdi, gen. et sp. nov.. Phylogenetic analysis of all Texas pterosaurs that can be coded for more than one character confirms that these species are distinct from others and occupy phylogenetic positions close to their original classifications. Radiodactylus langstoni is recovered as a non-azhdarchid azhdarchoid, Quetzalcoatlus northropi as an azhdarchid, Alamodactylus byrdi as a non-pteranodontoid pteranodontian, Aetodactylus as a pteranodontoid, and Coloborhynchus wadleighi as an ornithocheirid. The presence of eudimorphodontid, dsungaripterid, as well as other azhdarchid and pteranodontoid pterosaurs, is also confirmed in Texas.

In Part I brief descriptions are given of the goniatite faunas found at horizons in the Scottish Carboniferous succession; and mainly on the evidence of these faunas, the stages of B, P1; P2, E1; and E2 and A are approximately demarcated. No goniatites suggesting the presence of H, R and G have been seen.

In Part II descriptions are given of certain species of the following genera: Beyrichoceratoides, Anthracoceras, Cravenoceras, Cravenoceratoides, Girtyoceras, Eumorphoceras, Goniatites, Sudeticeras, Dimorphoceras, Neodimorphoceras and a new genus, Cluthoceras.

High Precision U-Pb zircon and monazite dating in the Aiguilles Rouges–Mont Blanc area allowed discrimination of three short-lived bimodal magmatic pulses: the early 332 Ma Mg–K Pormenaz monzonite and associated 331 Ma peraluminous Montées Pélissier monzogranite; the 307 Ma cordierite-bearing peraluminous Vallorcine and Fully intrusions; and the 303 Fe-K Mont Blanc syenogranite. All intruded syntectonically along major-scale transcurrent faults at a time when the substratum was experiencing tectonic exhumation, active erosion recorded in detrital basins and isothermal decompression melting dated at 327-320 Ma. Mantle activity and magma mixing are evidenced in all plutons by coeval mafic enclaves, stocks and synplutonic dykes. Both crustal and mantle sources evolve through time, pointing to an increasingly warm continental crust and juvenile asthenospheric mantle sources. This overall tectono-magmatic evolution is interpreted in a scenario of post-collisional restoration to normal size of a thickened continental lithosphere. The latter re-equilibrates through delamination and/or erosion of its mantle root and tectonic exhumation/erosion in an overall extensional regime. Extension is related to either gravitational collapse or back-arc extension of a distant subduction zone.

There is abundant evidence of injury, teratology and pathological conditions in trilobites although it is commonly difficult to distinguish between their morphological results. Many injuries were probably sustained during moulting, with spines, bilamellar fringes and narrow gaps between dorsal exoskeleton and doublure being most vulnerable. Some injuries were the result of predaceous attack and provide important clues to the trophic structure of Palaeozoic communities. Many injuries show evidence of repair. Some supposedly teratological conditions, most notably the number of paradoxidid thoracic segments, are so common that they must be considered part of normal variation. Others represent genetic mutation or ontogenetic malfunction, the latter possibly externally induced. Undoubted pathological conditions are restricted to swellings and borings presumably caused by parasitic infestation.

Abnormalities affecting lateral areas are more common than those involving the rachis and glabella and this probably reflects both greater mortality when the axial region is involved, and greater vulnerability of peripheral regions to predaceous and moulting damage. The first explanation also accounts for the rarity of cephalic abnormalities compared to those of the pygidium.

In 1804, Lieutenant-Colonel Imrie communicated to the Royal Society of Edinburgh a paper entitled “A Description of the Strata which occur in ascending order from the Plains of Kincardineshire to the Summit of Mount Battoc, one of the most elevated points in the Eastern District of the Grampian Mountains.” He pointed out that, in a short stretch of six miles in the North Esk section, “we pass from the secondary horizontal strata of the newest formation to the vertical, contorted primary strata of the oldest date, and terminate with granite, the primitive rock in the conception of many geologists.”

Sensitivity experiments with general circulation models show that uplift of plateau and mountain regions in Southern Asia and the American west during the late Cenozoic was an important factor in the evolution of Northern Hemisphere climate. The climatic trends simulated in the uplift experiments agree in direction with most trends observed in the geological record, including the tendencies toward greater regional differentiation of climate, and particularly the fragmentation into wetter and drier climatic patterns at middle latitudes. These climatic trends result from (1) increased orographic diversion of the mid-latitude westerlies, and (2) increased summer heating and winter cooling over the plateaus, which enhances seasonally reversing (monsoonal) changes in wind directions.

Most previous hypotheses addressing the physical impact of orography on climate have focused on mountain ranges and have stressed relatively local responses such as upslope precipitation maxima, cooling of mountain crests due to lapse-rate effects on rising terrain, and lee-side rainshadow effects. In contrast, our results emphasise the importance of large-scale plateau orography. By redirecting the basic directions of wind flow both at surface and upper-tropospheric levels, these rising plateaux cause far-reaching climatic changes that extend across the continents as well as over the oceans.

The Schichallion complex is situated in the Central Highlands of Scotland between the villages Struan and Kinloch Rannoch. The area is of considerable geological interest and has been investigated stratigraphically and structurally by E. M. Anderson and Bailey and McCallien. As a consequence of their researches a complete stratigraphical succession has been established. Thus, the metamorphic rocks of the area are classified into the Moinian and Dalradian systems, which are separated by a plane of tectonic discontinuity known as the Boundary Slide. The Moinian rocks are quartz-felspathic granulites, whereas the Dalradian system includes pelitic schists, quartzites, limestones as well as a variety of meta-igneous rocks.

In his previous research the present author has established the tectonic history of the complex. In particular three episodes of folding (F1 to F3) and a much later episode of faulting (F4) were recognized. Of these the F3 episode is of least significance. Consequently, events after the F2 movements can be in many cases regarded as post-folding.

The present contribution is concerned essentially with the mapping of the metamorphic zones (garnet and staurolite-kyanite) and with a detailed study of the mineralogical evolution of regionally metamorphosed rocks within these zones.

In the field it is possible to prove that the staurolite-kyanite zone is essentially post-folding, since the kyanitepegmatites are found to cut across the minor F2-folds. In this respect textural studies confirm the field observations. The study of the internal inclusions in garnets indicates that the garnet zone has a much longer history, since pre-F2 garnets are found in the southern part of the complex and throughout the central part of the area syn-tectonic F2 garnets are apparent. The pre-F2 garnets contain a very fine-grain F1 fabric. Hence the garnets in relation to the F1 movements are post-tectonic. Thus, the regional metamorphism can be subdivided into three phases: the F1 metamorphism, the F2 metamorphism and the post-F2 metamorphism. The latter, on structural evidence appears to be at least in part contemporaneous with the F3 movements.

The meta-igneous rocks of the area are grouped into the hornblende-schists and granular epidiorites. The hornblende-schists appear to have suffered deformation and recrystallization during F1 and F2 episodes of movement. On the other hand the granular epidiorites are later than the F1 and the F2 movements. Although in the southern parts of the district the epidiorites have been slightly deformed, elsewhere they preserve the original ophitic texture and cut across the F1 and F2 folds. The deformation in the south is attributed to the effects of the F3 folding. The epidiorites have been evidently emplaced as dolerites after the F2 movements and before the F3 metamorphism.

The localized retrogressive metamorphism is associated with the F4 movements, which are responsible for the Loch Tay Fault. The Fault is later than the minor intrusives associated with the Younger Granites of the Scottish Highlands and is suggested to be of a Lower or Middle O.R.S. age.

On the basis of the chemical composition of the plagioclase felspars it is proposed to include all the staurolite and kyanite bearing rocks into the epidote-amphibolite facies. In this respect temperature and the hydrostatic pressure are assumed to have been the main factors, since similar minerals came into existence during static and dynamic stages of metamorphism alike.

Eusuchians with deep snouts and labiolingually compressed teeth are known from the Palaeogene of Laurasia. These are usually referred to Pristichampsinae, but the type species, Pristichampsus rollinati, is based on insufficiently diagnostic material and should be treated as a nomen dubium. At least two Lutetian species formerly referred to Pristichampsus can be recognised – Boverisuchus magnifrons in Germany and possibly elsewhere in Europe, and Boverisuchus vorax, new combination, in western North America. Material from the middle Eocene of Italy and Texas may represent distinct species. A phylogenetic analysis confirms their close relationship and also supports a relationship with two Asian forms – early Eocene Planocrania datangensis and Palaeocene Planocrania hengdongensis. The name Planocraniidae Li 1976 is applied to this group. A distinctive quadrate with a prominent dorsal peak between medial and lateral hemicondyles is known only in Boverisuchus, and although the teeth of Planocrania are flattened, they are not serrated. Planocraniids maintain a phylogenetic position as the sister group to Crocodyloidea+Alligatoroidea, but this part of the tree is unstable and discovery of older, more primitive planocraniids will help resolve conflicts on the phylogenetic relationships of extant crocodylian lineages.

The Watch Hill Grits, in the lower Ordovician Skiddaw Group of the Lake District, are dated as latest Tremadoc or earliest Arenig (older than the Didymograptus deflexus Biozone) by means of acritarchs and graptolites. This places them lower in the Skiddaw sequence than previous authors supposed, and they are thought to have been thrust southwards over younger Arenig rocks. The interval inferred for the Watch Hill Grits brackets the Tetragraptus approximatus Biozone and its equivalents in Australasia, S China, N America and Scandinavia. The dating of the Watch Hill Grits suggests that equivalents of the Tetragraptus approximatus Biozone are present in N England and that sedimentation continued in the Lake District during a period of global eustatic regression. Other beds in the Lake District and on the Isle of Man have yielded similar acritarch assemblages and are probably correlatives. Five new acritarch taxa are described: Caldariola gen. nov., Acanthodiacrodium? dilatum, Stellechinatum sicaforme and Striatotheca prolixa spp. nov., and Tetraniveum arenigum cumbriense subsp. nov.; one new combination, Caldariola glabra (Martin) comb, nov., is proposed.

Small phosphatised fossils from late Cambrian limestones of Västergötland, Sweden, share major external features with larval extant Pentastomida, such as a prominent head with two pairs of stumpy limbs adapted for attachment, and a slender trunk of four portions. Even such details, as paired forehead structures, pores on the inner edges of the head limbs and paired papillae at the rear of the trunk correspond with structures of extant pentastomid larvae. Neither the fossils nor the Recent pentastomids add any additional body segments during growth (segment constancy). Since characters of this kind and in this combination do not occur elsewhere, the fossils are recognised as true Pentastomida. Major differences, such as distinctly divided head limbs, partial occurrence of vestigial trunk limbs, and a different mode of trunk development during growth can be explained as representing merely the plesiomorphic state of characters of Pentastomida, indicating that the fossils are representatives of its stem-group prior to branching into the two Recent lineages. The fossils clearly document the marine origin of the Pentastomida, and that their specific morphology and parasitic life style were already established in the late Cambrian at a high degree of diversification, long before the terrestrialisation of their present final hosts, the tetrapods. General arthropod affinities are recognisable not least in the nature of the limbs, but the morphology of stem- and crown-group pentastomids gives no clues for closer relationship with any of the major (eu)arthropod taxa.

During recent years there has been a very great advance in our knowledge of the minute structure and function of the various regions and glands of the alimentary canal of the prosobranch and pulmonate gastropods, without any corresponding increase in our understanding of the opisthobranch and, in particular, of the nudibranch gut. That the emphasis should be laid on the streptoneurous and the land-living forms is obviously due to their abundance and to the fact that they include almost all the familiar types of gastropod mollusc, but it is disappointing that, at the moment of writing, there exists only one account of the histology and function of the digestive system of either a dorid or an æolid—to confine attention to the two main types of nudibranch molluscs which occur in British waters—that of Millott (1937b). This is perhaps more noticeable when it is recalled that the nudibranchs have specialised along distinctly unusual lines, many of which are intimately associated with the food and feeding habits which the animals have adopted. The æolids, it is true, have attracted a lively interest in connexion with their possession of nematocysts, but the majority of investigators have apparently been content to trace these into the cnidosacs without concerning themselves over the other constituents of the animal's food.

The two major lineages of extant archosaurs, crocodylians and avians, diverged in the Triassic, but the details and timing of this event are incompletely understood. Fragmentary and phylogenetically uninformative specimens, in addition to poor temporal constraints on rock units from the Early and Middle Triassic, typify obstacles in identifying early archosaurs. This paper re-describes the partial skeleton of the only known specimen of Xilousuchus sapingensis Wu, 1981 from the Early Triassic Heshanggou Formation in north-central China. Originally assigned to the non-archosaurian archosauriform clade Proterosuchidae, an extensive phylogenetic analysis posits X. sapingensis as a crown-group archosaur within Suchia, thus making this taxon the unequivocally oldest known member of Archosauria. The age and phylogenetic position of X. sapingensis indicate that many archosaurs, including all major clades of non-archosaurian archosauriforms, the avianline, ornithosuchids, aetosaurs and paracrocodylomorph lineages, must have diverged by the end of the Early Triassic. X. sapingensis is part of a possible clade of sail-backed poposauroids that were common components of archosaur assemblages during the Early to Middle Triassic.

Late Cretaceous (90–100 Ma) A-type granites are widespread in the coastal area of the Zhejiang and Fujian Provinces, SE China. According to mineralogical and geochemical characteristics, the A-type granites in this belt can be further divided into aluminous and peralkaline subgroups. The aluminous subgroup often contains aluminous-rich minerals (e.g. spessartine and Mn-rich muscovite), while the peralkaline subgroup usually contains riebeckite, arfvedsonite and aegirine. Geochemically, the aluminous A-type granites show lower Nb, Zr, Ga, Y and REE abundances, and lower FeO*/MgO and Ga/Al than the peralkaline subgroup. When they occur in the same area, the two subgroups of A-type granites display quite similar initial Nd isotopic compositions, which are indicative of mixing of ancient basement crustal rocks with variable amounts of mantle materials. Integrated geological and geochemical investigations indicate that both the aluminous and the peralkaline magmas are highly evolved and reflect the residual liquids left after high degrees of fractional crystallisation in a deep magma chamber. The present authors suggest that the mineralogical and geochemical differences between the aluminous and peralkaline subgroups are likely to have been generated via different differentiation paths controlled by varying fluorine contents of the parent magmas.

The Indian summer Southwest Monsoon plays an important part in influencing, and regulating, the productivity and sedimentation in the northwest Arabian Sea at the present day, by driving coastal upwelling. This leaves permanent sedimentological and geochemical records in the accumulating deep-sea sediments. Cores 722B and 724C were raised from the Owen Ridge and Oman Margin, respectively, during Leg 117 of the Ocean Drilling Program and have been subjected to geochemical analyses and α-spectrometry. A comparative core, CD17–30, situated on the adjacent Indus Fan abyssal plain, has also been studied. The chronostratigraphy of the cores has been established with δ 18O stratigraphy, giving a 350 ka climate record. Changes in the total sediment mass accumulation rates occur on glacial/interglacial time scales, with maximum fluxes occurring during glacial episodes. The high fluxes are predominantly due to wind-transported dust at the ridge and margin sites. Compositional parameters (e.g. the Ti/Al ratio) indicating the proportion of heavy minerals present within the dust, suggests that strong winds associated with the Southwest Monsoon, occur with Milankovitch periodicities, and are dominated by the precession (23 ka) frequency. The wind strength controls the proportion of heavy minerals transported to the Arabian Sea, whilst continental aridity influences the timing of deflation from the Arabian and Somalian peninsulas. Tracers of palaeoproductivity (Ba/Al) indicate strong coherence and phase with the proxy ice volume (foraminiferal δ 18O) signal, suggesting global climate parameters (ice volume, continental aridity) determine coastal productivity by influencing nutrient supply. In relation to productivity, the roles of oceanic circulation/stratification and nutrient supply through continental runoff are discussed. This study shows that the Southwest Monsoon appears to only affect the shorter period (precession cycle, 23 ka band) productivity signal. Evidence from excess 230Th suggests deep oceanic circulation (at about 2000 m depth) was more intense 110 ka BP decreasing toward 40 ka BP. By the use of these various geochemical tracers a new, and comprehensive, view of the interaction of the Monsoon and global climate with marine productivity through the late Pleistocene has been obtained.