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The horned dinosaur genus Torosaurus has a challenging history, relating both to its geographic distribution and taxonomy. Whereas Torosaurus has been reported from Upper Maastrichtian deposits in Canada, which would mark the northernmost range of the genus, recent work has questioned the generic identity of the implicated material, which primarily consists of a pair of cranial frills. Perhaps more problematically, the validity of the genus itself has been a subject of recent debate, with some arguing that Torosaurus is simply a skeletally mature growth form of the contemporaneous Triceratops. In this study, we describe and illustrate the relevant frill material from Canada, and determine that it is most plausibly attributable to the Torosaurus morph. Moreover, we apply for the first time osteohistological sampling to some postcranial material associated with one of the frills, and find that the animal was still growing at the time of death. This finding, in addition to other considerations presented here, leads us to conclude that Torosaurus is a valid genus, and is not simply a mature growth form of Triceratops. [ABSTRACT FROM AUTHOR]

Paleopathology, or the study of ancient injuries and diseases, can enable the ecology and life history of extinct taxa to be deciphered. Large‐bodied ornithopods are the dinosaurs with the highest frequencies of paleopathology reported to‐date. Among these, the crested hadrosaurid Parasaurolophus walkeri is one of the most famous, largely due to its dramatic elongated and tubular nasal crest. The holotype of Parasaurolophus walkeri at the Royal Ontario Museum, Canada, displays several paleopathologies that have not been discussed in detail previously: a dental lesion in the left maxilla, perhaps related to periodontal disease; callus formation associated with fractures in three dorsal ribs; a discoidal overgrowth above dorsal neural spines six and seven; a cranially oriented spine in dorsal seven, that merges distally with spine six; a V‐shaped gap between dorsal spines seven and eight; and a ventral projection of the pubic process of the ilium which covers, and is fused with, the lateral side of the iliac process of the pubis. These lesions suggest that the animal suffered from one or more traumatic events, with the main one causing a suite of injuries to the anterior aspect of the thorax. The presence of several lesions in a single individual is a rare observation and, in comparison with a substantial database of hadrosaur paleopathological lesions, has the potential to reveal new information about the biology and behavior of these ornithopods. The precise etiology of the iliac abnormality is still unclear, although it is thought to have been an indirect consequence of the anterior trauma. The discoidal overgrowth above the two neural spines also seems to be secondary to the severe trauma inflicted on the ribs and dorsal spines, and probably represents post‐traumatic ossification of the base of the nuchal ligament. The existence of this structure has previously been considered in hadrosaurs and dinosaurs more generally through comparison of origin and insertion sites in modern diapsids (Rhea americana, Alligator mississippiensis, Iguana iguana), but its presence, structure, and origin‐attachment sites are still debated. The V‐shaped gap is hypothesized as representing the point between the stresses of the nuchal ligament, pulling the anterior neural spines forward, and the ossified tendons pulling the posterior neural spines backward. Different reconstructions of the morphology of the structure based on the pathological conditions affecting the neural spines of ROM 768 are proposed. Finally, we review the history of reconstructions for Parasaurolophus walkeri showing how erroneous misconceptions have been perpetuated over time or have led to the development of new hypotheses, including the wide neck model supported in the current research. [ABSTRACT FROM AUTHOR]

We report the discovery of Maculaferrum blaisi gen. et sp. nov, the first occurrence of the family Tettigarctidae, informally known as hairy cicadas, in North America. Maculaferrum blaisi is part of a new collection assembled during recent fieldwork in the Redmond Formation, Labrador, Canada, near Schefferville. It consists in a single isolated forewing whose venational characters allow a classification to Tettigarctinae at the subfamily level. Classification at a higher level remains uncertain since it displays a combination of characters supposedly unique to tribes Protabanini, Meunierini, and Tettigarctini. Thus, this discovery adds credence to suggestions of a revision of the definitions of these tribes since they seem to be based on many convergent or plesiomorphic characters. Remnants of a spotted pattern on the wing membrane and probable setae along some veins are also preserved. Observations of the holotype's fine anatomical characters have been facilitated by the use of Reflectance Transformation Imaging (RTI), an emerging method for the visualization of compression and impression fossils. Considering that the estimated age of the Redmond Formation is the Cenomanian (Late Cretaceous), the discovery of M. blaisi contributes to a very recent expansion of the tettigarctid fossil record that fills a gap between Early Cretaceous and Cenozoic genera. It suggests that hairy cicadas maintained a global distribution and thrived in a variety of climate regimes well into the Late Cretaceous, and that their competitive exclusion by singing cicadas occurred definitely closer to the end of the Cretaceous, or even during the Cenozoic. This discovery is only the start of a thorough description of the recently expanded entomofauna in the Cretaceous of Labrador. [ABSTRACT FROM AUTHOR]

We report the discovery of Maculaferrum blaisi gen. et sp. nov, the first occurrence of the family Tettigarctidae, informally known as hairy cicadas, in North America. Maculaferrum blaisi is part of a new collection assembled during recent fieldwork in the Redmond Formation, Labrador, Canada, near Schefferville. It consists in a single isolated forewing whose venational characters allow a classification to Tettigarctinae at the subfamily level. Classification at a higher level remains uncertain since it displays a combination of characters supposedly unique to tribes Protabanini, Meunierini, and Tettigarctini. Thus, this discovery adds credence to suggestions of a revision of the definitions of these tribes since they seem to be based on many convergent or plesiomorphic characters. Remnants of a spotted pattern on the wing membrane and probable setae along some veins are also preserved. Observations of the holotype's fine anatomical characters have been facilitated by the use of Reflectance Transformation Imaging (RTI), an emerging method for the visualization of compression and impression fossils. Considering that the estimated age of the Redmond Formation is the Cenomanian (Late Cretaceous), the discovery of M. blaisi contributes to a very recent expansion of the tettigarctid fossil record that fills a gap between Early Cretaceous and Cenozoic genera. It suggests that hairy cicadas maintained a global distribution and thrived in a variety of climate regimes well into the Late Cretaceous, and that their competitive exclusion by singing cicadas occurred definitely closer to the end of the Cretaceous, or even during the Cenozoic. This discovery is only the start of a thorough description of the recently expanded entomofauna in the Cretaceous of Labrador. [ABSTRACT FROM AUTHOR]

Abstract In the southern Athabasca Oil Sands (SAOS) Region, located in Alberta Canada, individual in-situ oil sands operators have conducted local geochemical and isotope groundwater studies to establish baseline characteristics and to improve understanding of the connectivity of water supply and disposal formations within individual leases. Canada's Oil Sands Innovation Alliance (COSIA) initiated this study to combine the data from these individual studies along with public information into a comprehensive unified dataset to evaluate conceptual models of regional groundwater flow and the degree of interaction and separation between important water supply and disposal aquifers. The unified dataset comprised over 293 groundwater samples from the main water source and disposal hydrostratigraphic units and included geochemical and isotopic tracers that can be used to identify sources (δ18O and δ2H) and age of water (3H) and associated solutes (14C DIC , 36Cl), as well as the sources of salinity and diagenetic processes (δ13C DIC , δ34S SO 4 , 87Sr/86Sr, δ11B, δ37Cl and δ81Br) and dissolved organics (δ13C DOC). The TDS and stable isotope composition (δ18O and δ2H) of groundwater from several Cretaceous formations were used to identify three main mixing controls. i) Areas where locally recharged groundwater mixes with glaciogenic water were identified by lower δ18O and δ18O values, high TDS, Cl:Br and δ34S SO4 , 87Sr/86Sr, and δ37Cl values consistent with dissolution of evaporites. These areas were situated where vertical pathways through otherwise competent formations are likely to occur. ii) Mixing with paleo-waters characterized by high TDS and higher δ18O and δ2H signatures indicating groundwater recharged under warmer climate periods and/or evaporative enrichment were identified in the south, and southwestern portions of the study area. The presence of these paleo-waters indicate slow-moving groundwater zones with limited lateral and vertical connectivity. iii) Areas with potential connectivity to shallow aquifers were identified by their lower TDS values, modern meteoric δ18O and δ2H signatures, HCO 3 type waters, and δ34S SO 4 and 87Sr/86Sr signatures, consistent with weathering of shallow aquifer material. Geochemical and isotopic indicators suggest that in areas where the Colorado Group aquitard is thin or absent, there is greater connectivity between the Grand Rapids Formation and the shallower aquifers. Interpretation of the new unified dataset has improved understanding of the extent that glacial recharge had on Devonian aquifers, and overlying Cretaceous formations, and identified zones with relatively stagnant groundwater flow, both of which have implications for regional groundwater resource development, monitoring and potential wastewater disposal. Highlights • Salinity in Cretaceous formation groundwater shows evidence of three main mixing trends. • High TDS groundwaters with more negative δ18O signatures indicate mixing with glaciogenic waters. • High TDS groundwaters with more positive δ18O values indicate mixing with paleowaters in some isolated areas. • Connectivity to shallow aquifers was identified by lower TDS values and HCO 3 type waters. • Presence of the Colorado Group aquitard and Devonian dissolution features have influenced vertical hydraulic connectivity. [ABSTRACT FROM AUTHOR]

New specimens of fossil homolid crabs collected from Cretaceous and Paleogene rocks from Canada and the western United States increase the fossil record of the Homolidae De Haan, 1839. Cretalamoha n. gen., n. sp. is reported from the Campanian Pender Formation, Vancouver Island, British Columbia, Canada. A new species, Paromola roseburgensis n. sp. from the early Eocene Roseburg Formation in Oregon, U.S.A. represents the second report for the genus in the fossil record and the first one in North America, extending the spatial and temporal ranges of the genus, from the Oligocene of Argentina to the Eocene of the North Eastern Pacific. Additional material from the Oligocene of Judkins Ridge, near Eugene, Oregon, U.S.A. assigned to Palehomola gorrelli Rathbun, 1926, allows re-evaluation of the systematic position of the genus, previously ascribed to the Homolodromiidae Alcock, 1900. The definite presence of linea homolica justifies removal of Palehomola from this family and inclusion within the Homolidae. [ABSTRACT FROM AUTHOR]

Microvertebrate assemblages of the Upper Cretaceous (late Cenomanian to mid-Turonian) Favel Formation of Manitoba are formally described for the first time. New vertebrate occurrences from the Favel Formation include the actinopterygians Caturidae indet., cf. Albulidae incertae sedis , Micropycnodon kansasensis , Pachyrhizodus minimus , Protosphyraena sp., Thryptodus loomisi , chondrichthyans Ischyrhiza cf. mira , I. texana , Ptychodus marginalis , P. occidentalis , and P. rhombodus , the avian cf. Ichthyornis sp., the reptile Testudines indet., and an unknown taxon referred to as Vertebrate A. Changes in faunal occurrences throughout the formation suggest an offshore open marine environment for the lower and middle horizons and nearshore marine for the upper horizon, represent ing mid- and late stages of the Greenhorn third-order marine cycle. This newly described diversity increases biogeographic affinities of the late Cenomanian to mid-Turonian vertebrate assemblages of Manitoba with central WIS localities in South Dakota and Kansas, providing additional support for a central vertebrate biogeographic subprovince during late Cenomanian to early Turonian times, as well as WIS localities further south in Texas decreasing the gradient of the north-south or central-south community boundary during early and mid-Turonian times., Competing Interests: The authors declare that they have no competing interests., (© 2023 Kilmury et al.)

PREMISE OF THE STUDY: Mosses, very diverse in modern ecosystems, are currently underrepresented in the fossil record. For the pre-Cenozoic, fossil mosses are known almost exclusively from compression fossils, while anatomical preservation, which is much more taxonomically informative, is rare. The Lower Cretaceous of Vancouver Island (British Columbia, Canada) hosts a diverse anatomically preserved flora at Apple Bay. While the vascular plant component of the Apple Bay flora has received much attention, the numerous bryophytes identified at the locality have yet to be characterized. METHODS: Fossil moss gametophytes in more than 20 carbonate concretions collected from the Apple Bay locality on Vancouver Island were studied in serial sections prepared using the cellulose acetate peel technique. KEY RESULTS: We describe Tricosta plicata gen. et sp. nov., a pleurocarpous moss with much-branched gametophytes, tricostate plicate leaves, rhizoid-bearing bases, and delicate gametangia (antheridia and archegonia) borne on specialized branches. A new family of hypnanaean mosses, Tricostaceae fam. nov., is recognized based on the novel combination of characters of T. plicata. CONCLUSIONS: Tricosta plicata reveals pleurocarpous moss diversity unaccounted for in extant floras. This new moss adds the first bryophyte component to an already diverse assemblage of vascular plants described from the Early Cretaceous at Apple Bay and, as the oldest representative of the Hypnanae, provides a hard minimum age for the group (136 Ma). [ABSTRACT FROM AUTHOR]

Premise of the study: Two ovulate conifer cones, one of which is attached terminally to a short leafy shoot, reveal the presence of a new species of Hughmillerites in the Early Cretaceous Apple Bay flora of Vancouver Island, British Columbia, Canada. This ancient conifer expands the diversity of Cupressaceae in the Mesozoic and reveals details about the evolution of Subfamily: Cunninghamioideae. • Methods: Specimens were studied from anatomical sections prepared using the cellulose acetate peel technique. • Key results: Vegetative shoots have helically arranged leaves that are CunninghamiaAike. Seed cones have many helically arranged bract/scale complexes in which the bract is larger than the ovuliferous scale. Each ovuliferous scale has three free tips that separate from the bract immediately distal to an inverted seed. Several ovuliferous scales show interseminal ridges between seeds. • Conclusions: This study documents a new extinct species of cunninghamioid conifers, Hughmillerites vancouverensis, expanding the record of the genus from the Late Jurassic to the Early Cretaceous. This new extinct species emphasizes the important role that conifers from subfamily Cunninghamioideae played in the initial evolutionary radiation of Cupressaceae. In light of recent findings in conifer regulatory genetics, we use H. vancouverensis to hypothesize that variations of expression in certain gene homologues played an important role in the evolution of the cupressaceous ovuliferous scale. [ABSTRACT FROM AUTHOR]

We used a molecular analysis based upon three genes, coupled with the ultrastructure of scales and bristles, to investigate phylogenetic relationships within Mallomonas, with a focus on the section Planae. Fossil taxa discovered in Middle Eocene lacustrine deposits from northwestern Canada were used to calibrate a relaxed molecular clock analysis and investigate temporal aspects of species diversification. Four new extant species, Mallomonas lacuna, M. hexareticulata, M. pseudomatvienkoae, M. sorohexareticulata, and one new fossil species. M. pleuriforamen, were described on the basis of morphological differences, including the number, distribution, and size of base plate pores, the secondary structures on scale surfaces, and characteristics of the bristles. Four of the new species align with M. matvienkoae and the fifth with M. caudata. Molecular phylogenetic analyses inferred using nuclear-encoded small-subunit ribosomal (r)DNA and large-subunit rDNA and plastid-encoded rbcL sequences placed four of the new species with M. matvienkoae, the fifth with M. caudata, all in a strongly supported clade within the section Planae. A Bayesian relaxed clock analysis showed that the genus Mallomonas diverged into two major clades about 33 Ma (Early Cretaceous), one of which represents the section Planae. The earliest diverging lineage within the section Planae was M. bangladeshica, followed by M. heterospina and M. oviformis, and most recently by M. sorohexaresiculata and M. hexareticulata. [ABSTRACT FROM AUTHOR]

The fossiliferous ironstone deposits of the Upper Cretaceous Horseshoe Canyon Formation in the Drumheller badlands, Alberta, Canada, contain a diverse, anatomically preserved flora. Within this assemblage occur abundant stems, leafy shoots, leaves, ovuliferous cones, and pollen cone clusters that are here described as a new species of Cunninghamia. The stems have persistent leaf bases and plagiotropic branching. Some stems show several growth increments, and the cortex and pith are made up of resin canals, large parenchymatous cells, and lysigenous cavities. Leafy shoot axes have parenchymatous cells, resinous cells, lysigenous cavities, and resin canals within the cortex and pith. The leaves are helically arranged, lanceolate to falcate, with two abaxial stomatal bands, a large central resin canal, and two smaller lateral canals. The ovuliferous cones have numerous helically arranged bract scale complexes. The bracts and three-lobed ovuliferous scale are variously ornamented. Anatomical features of bracts include a well-defined hypodermal layer and resin canals with adaxial traces. A single vascular trace enters the complex and divides to produce the ovuliferous-scale trace and bract traces. Ovules/seeds are ovoid and weakly winged. The pollen cone-bearing branch apices show stalks of at least 17 pollen cones arranged in a pseudowhorl. Each stalk consists of an inflated base surrounded by 5-6 scale-like leaves. The anatomy and morphology of the fossil material agrees so closely with that of modern Cunninghamia that we are confident in describing it as a new species of this genus, Cunninghamia taylorii sp. nov. The present material provides a rare opportunity to contribute toward a better understanding of the specific variation, biology, ecology, and evolutionary history of cunninghamioid Cupressaceae. [ABSTRACT FROM AUTHOR]

Abstract: Diagenesis in the uppermost Jurassic to Lower Cretaceous deltaic sandstones and shales of the Scotian Basin is an important control on reservoir quality. Ferruginous zone (sub-oxic) marine pore-water diagenesis controls the initial formation of Fe2+-silicates that are the precursors of grain-rimming chlorite that preserves porosity. This study assesses the regional controls on the type of marine pore-water diagenesis by studying the sedimentology, mineralogy, and geochemistry of the retrogradational units and underlying progradational units in parasequences from conventional cores in two wells in different parts of the basin. Coated grains preserve a record of whether marine pore-water diagenesis below the seafloor was dominantly in the ferruginous or sulphidic geochemical zone. Four types of coated grain were distinguished, each with a different mineral paragenesis. Mineralogical and chemical evidence of ferruginous zone diagenesis includes the presence of diagenetic chlorite and siderite, and the correlation of P with Fe or Ti. Pyrite and Fe-calcite are found where the sulphidic zone is more significant than the ferruginous zone. Ferruginous zone diagenesis was common in low-sedimentation rate retrogradational sediments with low organic carbon, and in delta-front turbidites and river-mouth sandstones. Estuarine, tidal flat and prodeltaic facies that are directly supplied by riverine sediments have a lower Fe:Ti ratio than do fully marine shoreface and open shelf facies as a result of input of detrital ilmenite and its alteration products. The relative contribution of colloidal iron (hydr)-oxides appears greater in distal low-sedimentation rate environments. Where large changes in sedimentation rate occurred at ravinement surfaces, the underlying progradational rocks have evidence of ferruginous zone diagenesis, whatever their facies. Rapid upward migration of the pore-water profile resulting from the change in sedimentation rate reduced the time available for mineral products to form in the deeper pore-water zones. This study has shown that the availability of Fe and organic carbon varying in a complex manner in marine deltaic sediments, but that the resulting diagenesis by marine pore-water can be predicted from facies and paleogeographic setting. [Copyright &y& Elsevier]

Reanalysis of the skull of the crested Asian hadrosaurine Saurolophus angustirostris confirms its status as a distinct species from its North American relative, Saurolophus osborni. In addition to its greater absolute size, S. angustirostris is differentiated from Saurolophus osborni by an upturned premaxillary body, a more strongly reflected oral margin of the premaxilla, the absence of an anterior notch in the prenarial fossa, a sigmoidal contour of the ventral half of the anterior process of the jugal, a shallow quadratojugal notch on the quadrate, and by a strongly bowed quadrate in lateral view. Phylogenetic analysis corroborates a sister taxon relationship between S. angustirostris and S. osborni. Saurolophus itself is characterised by a solid, rod-like crest composed of the nasals, frontals, and prefrontals; secondary elongation of the frontal and prefrontal resulting in the backwards extension of the frontal platform; a frontal platform that extends dorsal to the anterior portion of the supratemporal fenestra; a parietal that is excluded by the squamosals from the posterodorsal margin of the occiput; and the presence of two supraorbital elements. Although the palaeobiogeographic history of Saurolophus remains unresolved, at least two possible dispersal events took place across Beringia during the late Campanian leading to the evolution of the clade composed of Kerberosaurus, Prosaurolophus, and Saurolophus. [ABSTRACT FROM AUTHOR]

Abstract: Mid-Cretaceous strata within the Tintina Trench, 3 km west of the community of Ross River, contain evidence of deposition in two distinct, alternating, fluvial settings. Coal-bearing, mud-dominated strata are commonly associated with high-constructive sandy channel systems, with extensive overbank, levee and splay deposits. Channels are between 3 and 30 m wide and 0.4–7 m thick. They show repetitive development of side and in-channel bar-forms, as well as up-channel widening of the rivers by selective erosion of associated overbank and levee deposits. Levees extended for several hundred metres away from the channels. In this setting low-angle inclined stratification and epsilon cross stratification may reflect lateral migration of crevasse channels or small streams. The paucity of exposure prevents recognition of the channels as products of multiple channel anastomosed systems or single channel high-constructive systems. Gravel-dominated strata, inter-bedded with, and overlying coal-bearing units, are interpreted as deposits of wandering gravel-bed rivers, with sinuosity approaching 1.4. In most exposures they appear to be dominated by massive and thin planar-bedded granule to small pebble conglomerates, which would traditionally be interpreted as sheet-flood or longitudinal bar deposits of a high-gradient braided stream or alluvial fan. Architectural analysis of exposures in an open-pit shows that the predominance of flat bedding is an artefact of the geometry of the roadside exposures. In the pit the conglomerates are dominated by large scale cross stratification on a scale of 1–5.5 m. These appear to have developed as downstream and lateral accretion elements on side-bars and on in-channel bars in water depths of 2–12 m. Stacking of strata on domed 3rd order surfaces suggests development of longitudinal in-channel bar complexes similar to those observed in parts of the modern Rhône River system. Mudstone preserved in some of the channels reflects intervals of channel abandonment or avulsion. Minimum channel width is from 70 to 450 m. [Copyright &y& Elsevier]

Abstract: Cretaceous sediments in the Northern Interior Plains are widespread and their interbasinal lithostratigraphic correlations indicate several regional unconformities that require biostratigraphic confirmation. This study proposes a new zonation based on benthic foraminifera utilising the reference section for the Albian to Turonian Arctic Red and Trevor formations located along the Hume River in the Peel Plateau region (Northwest Territories). A new absolute age date of 107.0±1.9Ma from a bentonite extends the biostratigraphic range of the Early Albian Quadrimorphina albertensis Zone into the Middle Albian. Integration of the new temporal framework with detailed sedimentological observations provides an interpretation of the dynamic depositional history for this northern region of the Western Interior Seaway (WIS). Cretaceous strata in the Peel Plateau record deposition of the initial transgression of the WIS in two pulses of relative sea-level rise (Martin House Formation) and subsequent offshore marine sedimentation in a deep foreland basin (Arctic Red Formation). The global eustatic sea-level minimum at the Albian–Cenomanian boundary and renewed uplift of the Keele Arch impacted palaeogeography in this region with previously unnoticed subaerial exposure and palaeosol development. This unconformity can be correlated to the east into the Mackenzie Plain. Transgression brings anoxic bottom waters during the Early Cenomanian (Slater River Formation) that result in an interval almost barren of foraminifera. During the Turonian, a time of high eustatic sea-level, the study area marks a relatively shallow site where pulses of prograding shorelines are recorded in upward shallowing parasequences bound by pebble lags overlain by flooding surfaces (Trevor Formation). East of the Peel Plateau in the Mackenzie Plain area, an unconformity separates Albian Arctic Red from ?Upper Cenomanian–Turonian strata, there named the Slater River Formation. In order to recognise the significant unconformity associated with the loss of Albian foraminifera and the angular unconformity observed in seismic profile, we propose the use of the Slater River Formation to describe the strata bound by the pisoidal ironstone and the first metre-plus sandstone bed marking the base of the interbedded mudstones and sandstones of the overlying Trevor Formation. The Hume River section is proposed as the type section for the Slater River Formation. [Copyright &y& Elsevier]

Acid preparation of samples of a bonebed from the Cenomanian of central Canada yielded several thousand well-preserved chondrichthyan teeth, in addition to numerous other vertebrate remains. Teeth and other remains of one species of chimaeroid, one species of hybodont shark, three species of Ptychodus, 10 species of neoselachian sharks and two species of batoid were recorded. The family Archaeolamnidae fam. nov., genera Meristodonoides gen. nov. and Telodontaspis gen. nov. and species Ptychodus rhombodus sp. nov., Telodontaspis agassizensis gen et sp. nov., Eostriatolamia paucicorrugata sp. nov., Roulletia canadensis sp. nov., Cretorectolobus robustus sp. nov. and Orectoloboides angulatus sp. nov. are described. Status of the genus Palaeoanacorax and the species Cretoxyrhina denticulata, Squalicorax curvatus and ‘ Rhinobatos’ incertus are discussed, and reconstructed dentitions of Archaeolamna and Roulletia presented. The fauna is of low diversity and dominated by active hunters, with many species apparently endemic to the northern Western Interior Seaway. [ABSTRACT FROM AUTHOR]

Abstract: The foraminifera from a Lower Cretaceous cored interval of Cohasset A-52 well (located on the Scotian Shelf) were used to interpret the depositional environments of these sediments. Paleoenvironmental interpretation was based on the analysis on 41 samples from four cored intervals of the well collected between 2069 and 2219m below seafloor. The interval consists of 25m of interbedded gray-black shale, mudstone and sandstone belonging to the Cree Member of the Logan Canyon Formation. The foraminiferal association recorded in the studied samples is comprised mainly of agglutinated specimens of Trochammina, Haplophragmoides, Ammobaculites and Verneuilinoides. A scattered occurrence of calcareous benthic foraminifera and thecamoebians is also recorded. A comparison of these microfauna with modern foraminiferal associations from paralic environments suggests that these sediments were deposited in a Cretaceous marsh–estuarine environment. [Copyright &y& Elsevier]

Abstract: Cunninghamia R. Brown ex. Richard is a cupressaceous arborescent conifer known from the Early Cretaceous to the Recent. Twelve specimens of permineralized leaves of Cunninghamia were identified from Late Cretaceous (Campanian) sediments on Hornby Island, British Columbia. The fossils, preserved in calcareous concretions, were examined using the cellulose acetate peel technique. The specimens are distinct from other Cunninghamia and Cunninghamia-like plants in that they appear to have a smooth leaf margin and are mostly epistomatic. The fossil leaves closely resemble the two extant species of Cunninghamia, C. lanceolata (Lambert) Hooker and C. konishii Hayata, in that they are helically arranged, some with incurved tips, and have similar leaf and stem anatomy. The Hornby Island leaves are compared to previously described extant and fossil Cunninghamia and leaves of Cunninghamiostrobus Stopes et Fujii with respect to internal anatomy. The Hornby specimens show a unique combination of characters and are described as a new species of Cunninghamia, C. hornbyensis. The presence of Cunninghamia-like plants in British Columbia demonstrates that these conifers were much more widespread in the Cretaceous than previously recognized. [Copyright &y& Elsevier]

Abstract: The Upper Cretaceous Upper Colorado Group, including the Carlile and Niobrara formations, reveals a complex and dynamic marine basin system in southern Alberta and southwestern Saskatchewan. An integrated study of the lower offshore to shelf environment, including sedimentology, geochemistry, petrophysics and micropaleontology demonstrates how sea-level fluctuations played a major role in the facies distribution and paleogeography of the Interior Seaway. Paleogeographic maps, depicting seven time slices covering the Late Turonian to Santonian, illustrate general lithologies and their distribution in the north-central part of the Interior Seaway of North America. These maps are based on data from southern Alberta and southwestern Saskatchewan integrated with studies of time-equivalent strata in neighboring regions in western Canada and northwestern U.S. The Interior Seaway reached its maximum extent during the peak transgression of the Greenhorn Cycle (Early Turonian) and the basin was gradually infilled starting in the Late Turonian with the Carlile Formation. The boundary between the Carlile and Niobrara formations is an angular unconformity where up to 20 m of the upper Carlile Formation was eroded. At this time (late Late Turonian), the Interior Seaway was a narrow strait of a few hundred kilometers with its basin axis in eastern Alberta. Marginal marine sandstones were deposited in western Alberta (Cardium Formation) and central Saskatchewan/north-central Montana (Bowdoin sandstone). The overlying transgressive part of the Niobrara Cycle shows multiple dramatic basin changes, with two examples of relative lowstand and complete basin drainage implied by the Verger Member (Coniacian). These rapid lowstand events occurred within periods of marine mudstone deposition, which indicate shelfal to offshore conditions. During deposition of the Medicine Hat Member (Early to Middle Santonian), changes from a shaly to a sandy shelf took place with deposition of thirteen sandstones in the vicinity of the Bow Island Arch of southern Alberta. During lowstand periods with low accommodation, the Bow Island Arch affected sedimentation, whereas during high accommodation, the arch had no influence. A subtle syncline in the northwest part of the study area is the primary reason for deposition of the main gas producing sandstone of the Medicine Hat Member. The maximum extension of the Interior Seaway during the Niobrara Cycle occurred in the late Santonian with the deposition of the First White Specks Member. [Copyright &y& Elsevier]

The Kaskapau Formation spans Late Cenomanian to Middle Turonian time and was deposited on a low-gradient, shallow, storm-dominated muddy ramp. Dense well log control, coupled with exposure on both proximal and distal margins of the basin allows mapping of sedimentary facies over about 35 000 km2. The studied portion of the Kaskapau Formation is a mudstone-dominated wedge that thins from 700 m in the proximal foredeep to 50 m near the forebulge about 300 km distant. Regional flooding surfaces permit mapping of 28 allomembers, each of which represent an average of ca 125 kyr. More than 200 km from shore, calcareous silty claystone predominates, whereas 100 to 200 km offshore, mudstone and siltstone predominate. From about 30 to 100 km offshore, centimetre-bedded very fine sandstone and mudstone record along-shelf (SSE)-directed storm-generated geostrophic flows. Five to thirty kilometres from shore, decimetre-bedded hummocky cross-stratified fine sandstone and mudstone record strongly oscillatory, wave-dominated flows whereas some gutter casts indicate shore-oblique, apparently mostly unidirectional geostrophic flows. Nearshore facies are dominated by swaley cross-stratified or intensely bioturbated clean fine sandstone, interpreted as recording, respectively, areas strongly and weakly affected by discharge from distributary mouths. Shoreface sandstones grade locally into river-mouth conglomerates and sandstones, including conglomerate channel-fills up to 15 m thick. Locally, brackish lagoonal shelly mudstones are present on the extreme western margin of the basin. There is no evidence for clinoform stratification, which indicates that the Kaskapau sea floor had extremely low relief, lacked a shelf-slope break, and was probably nowhere more than a few tens of metres deep. The absence of clinoforms probably indicates a long-term balance between rates of accommodation and sediment supply. Mud is interpreted to have been transported >250 km offshore in a sea-bed nepheloid layer, repeatedly re-suspended by storms. Fine-grained sediment accumulated up to a ‘mud accommodation envelope’, perhaps only 20 to 40 m deep. Continuous re-working of the sea floor by storms ensured that excess sediment was redistributed away from areas that had filled to the ‘accommodation envelope’, being deposited in areas of higher accommodation further down the transport path. The facies distributions and stratal geometry of the Kaskapau shelf strongly suggest that sedimentary facies, especially grain-size, were related to distance from shore, not to water depth. As a result, the ‘100 to >300 m’ depth interpreted from calcareous claystone facies for the more central parts of the Interior Seaway, might be a significant overestimate. [ABSTRACT FROM AUTHOR]

Early-late Cenomanian rocks of the Doe Creek unit are near the base of the Kaskapau Formation and were deposited in a broad, very shallow embayment that occupied the foredeep of the Western Canada foreland basin. The Doe Creek unit consists of 13 upward-shoaling sequences, typically 3-10 m thick. Subsurface correlation shows that sequences can be traced for 100-350 km from the foredeep toward the forebulge. On the proximal and distal margins of the embayment, each sequence is capped by a flooding surface, commonly underlain by a paleosol developed in marine mudstone. In the center of the embayment, most sequences are capped by one or more isolated, sharp-based sandstone bodies interpreted as lowstand delta-front deposits. Flooding surfaces on top of each sequence are continuously traceable in well logs from the foredeep to the vicinity of the forebulge, implying simultaneous transgression across the basin. Every sequence shows an abrupt upward shallowing, usually to emergence, that was caused by accommodation loss, not sediment accumulation. A vertical relative sea-level excursion of ∼10 m on a time scale spanning a maximum range of ∼9-74 k.y. is estimated for each sequence. Because transgressions and regressions appear to be in phase across the basin, sequences are better explained by eustasy rather than by flexural reciprocal sedimentation: a glacioeustatic mechanism provides the most likely explanation. [ABSTRACT FROM AUTHOR]

Abstract: The frontier Liard Basin is a relatively unexplored basin in northeastern British Columbia, southwestern Northwest Territories and southeastern Yukon Territory. Although it preserves a thick Cretaceous sedimentary succession, the relationships of these strata to those to the south in the Western Canada Sedimentary Basin (WCSB) are poorly understood. Outcrop sedimentary analysis along with foraminiferal micropaleontology and Rock-Eval pyrolysis are used to investigate the relative sea level and palaeoenvironmental changes that accompanied deposition of the upper Albian Sikanni Formation. Analysis of proximal and distal facies from three outcrops of the Sikanni Formation within the Liard Basin indicates that four sequences can be identified in offshore, wave-dominated shoreline, prodeltaic, delta front and delta plain litho- and biofacies. The identification of 105 yr cyclicity relative sea level changes that punctuated Sikanni deposition is supported by the presence of chert pebble lag deposits at surfaces interpreted as sequence boundaries. These sequences are regionally correlative in outcrops and well logs of the Sikanni Formation and indicate a previously unrecognized cyclicity in the upper Albian of the WCSB. Among the two causal mechanisms considered to have possibly driven the cycles, high frequency changes in flexural loading is probably responsible for the cyclicity observed, as evidence of basin-wide relative sea level changes necessary to support a eustatic interpretation is lacking in the late Albian of the WCSB. [Copyright &y& Elsevier]

The fossil record of aquatic flowering plants broadens our understanding of their former diversity and origins from terrestrial ancestors. This paper describes a floating aquatic monocot from 71 whole plants and several isolated leaf fragments from Upper Cretaceous oxbow lake sediments in the Dinosaur Park Formation, Alberta, Canada. The new material is represented by rosettes of leaves and roots attached to short stems that are interconnected by stolons and corresponds to the fossil aroid originally described as Pistia corrugata Lesquereux. Up to six plants have been found interconnected on a single slab suggesting that these plants grew in extensive floating mats covering lakes and calm stretches of rivers. Stems have up to six leaves and large numbers of branched aquatic roots. The leaf is trumpet-shaped with an elongate clasping petiole, large aerenchymatous base, and a nearly circular blade rim. Leaf bases are often filled with sediment giving the leaf the appearance of having a basal pouch. Petioles have 6-9 veins that divide into an upper and lower set, and veins converge at an apical notch. A submarginal collective vein and at least two marginal veins with branching veins form the leaf rim. A series of dichotomizing and anastomosing veins characterize the adaxial leaf surface. Tertiary and quatemary veins form polygonal areolae. Leaf surfaces are covered in trichomes that, like those in Pistia stratiotes, probably aided in buoyancy. A reconstruction of the plant is presented. Based on unique leaf morphology, these fossil plants are clearly not assignable to the genus Pistia and are described as Cobbania corrugata (Lesquereux) Stockey, Rothwell et Johnson gen. et comb. nov. Recent systematic analyses using molecular characters resolve two separate origins of floating aquatic aroids included in the duckweeds and the genus Pistia. This new fossil genus increases our understanding of colonization of aquatic habitats by revealing a third possible origin of the floating aquatic habit within Araceae. [ABSTRACT FROM AUTHOR]

A new fauna of Lower Cretaceous (Albian) ichthyosaurs, which includes at least one new genus and species, was recovered from deposits of the Loon River Formation at Hay River, Northwest Territories, Canada. All Cretaceous ichthyosaurs have been referred to a single genus, Platypterygius. The Loon River Formation material, however, does not satisfy the diagnosis for Platypterygius, and it is distinctive enough to warrant the erection of a new genus and species of ichthyosaur. Maiaspondylus lindoei gen. et sp. nov. is distinguished from other ichthyosaurs by an extensive overlapping contact of the jugal and the maxilla; marginal teeth with smooth crowns, fluted cementum, lingual curvature and implantation in a dental groove; and humerus with isomorphic proximal and distal ends, featuring three distal articular facets in which the medial articular facet is smaller than the lateral facets. The holotype and referred material is described here, and the relationship of Maiaspondylus to other ophthalmosaurs is discussed. [ABSTRACT FROM AUTHOR]

Abstract: A prior study involved 78 Collembola specimens preserved in Upper Cretaceous (Campanian) amber from Canada. This work deals with 109 specimens from the mid Cretaceous (Cenomanian or possibly slightly lower) of Myanmar, 37 of which have been identified to the generic level; 14 new species are described. Two species of the family Isotomidae are placed in previously described genera. One is placed in the Late Cretaceous genus Protoisotoma (burma), and one in the extant genus Proisotoma (s.l.) pettersoni. The remaining specimens are placed in 11 newly erected genera or as “Incertae sedis” taxa in the broadly construed families Sminthuridae, Isotomidae, and Neanuridae. The new genera are Sminthuridae (s.l.): Grinnellia, Sminthuricinus, Mucrovirga, and Sminthurconus; Isotomidae: Villusisotoma (two species, V. brevis and V. longa), Burmisotoma, Propachyotoma, and Protodesoria; Neanuridae (s.l.) Protodontella. Two new genera (Praentomobrya and Cretacentomobrya) are placed in a new family (Praentombryidae), which is similar to the modern family Entomobryidae. Most of the extinct genera are very similar to modern genera. This similarity, along with the occurrence of an extant genus, suggests that a greater proportion of the Collembola of Myanmar (Burma) survived the end-Cretaceous than did taxa in Canada, even though the former are approximately 30Ma older. [Copyright &y& Elsevier]

Permineralized rhizomes and stipe bases of filicalean ferns occur in the Upper Cretaceous (Campanian) Horseshoe Canyon Formation near the town of Drumheller in southern Alberta, Canada, and these provide an opportunity to describe the first anatomically preserved Mesozoic species of Blechnaceae/Dryopteridaceae. The two new fossil species also provide evidence that modern stelar architecture and stipe anatomy evolved in these families before the end of the Mesozoic. Midlandia nishidae gen. et sp. nov. has an apparently ascending radial rhizome from which stipes diverge in a helical pattern that approaches a 5/8 arrangement. The dictyostele is made up of amphicribral meristeles, and stipe traces consist of two hippocampiform bundles that flank three to four smaller circular bundles. The rhizome of Wessiea oroszii is somewhat smaller, with a dictyostele of five to seven cauline meristeles, from which stipe traces diverge as a pair of hippocampiform bundles. In both species, gaps in the stele are initiated by the divergence of a root trace, whereas stipe traces separate from the sides of the meristeles that flank the gap. The new species show numerous anatomical similarities to living blechnoid and dryopteroid ferns and strongly support hypotheses that these highly derived ferns originated before the Upper Cretaceous. [ABSTRACT FROM AUTHOR]

Several new broad-leaved monocots were identified in gray siltstones and fine-grained sandstones from the Upper Cretaceous (Campanian-Maastrichtian) St. Mary River Formation near Cardston, Alberta, Canada. Specimens are compression/impressions of long-petiolate aquatic plants that were probably buried in situ. Leaf blades are entire, ovate to elliptic, with deeply cordate bases; leaf blades are 5-12 cm long and 3.5-8.5 cm wide. Petioles are at least 4 mm wide with five to seven primary veins that enter the leaf blade. Venation is campylodromous, resulting in 23-27 primary veins with three medial veins that remain unbranched to the apex. Major and minor secondary veins (ABAB pattern) diverge at angles of 45°-65° near the midveins and 900 near the leaf margin. Tertiary veins are usually unbranched, but occasional dichotomies and anastomoses occur. No freely ending veinlets are visible. The Cardston specimens are compared with extant leaves of Alismatales and show closest similarities to those of Lirnnocharis L., Hydrocleys Rich., and Butomopsis Kunth. These leaves are also similar to fossil leaves of Haemanthophyllum Budantsev, in particular H. cordatum Golovneva from the Maastrichtian-Danian deposits of the Koryak Highlands, Russia. A reexamination of the genus Haemanthophyllum, the generitype (H. kamtschaticum Budantsev), the holotype for H. cordatum, and the Cardston specimens results in the description of a new genus, Cardstonia tolmanii gen. et sp. nov. (Limnocharitaceae). This study points to the need for reexamination of the remaining species in the genus Haemanthophyllum, which appear to represent a diverse assemblage of leaves of varying morphology that are probably not a natural group. [ABSTRACT FROM AUTHOR]

Two fossil poroid hymenophore fragments, one from the Cretaceous Period and the other from the Eocene Epoch, are described. The permineralized specimens were obtained from marine calcareous concretions on Vancouver Island, British Columbia, Canada, and were studied using the cellulose acetate peel technique. Size and distribution of pores in the hymenophores, as well as the hyphal anatomy of the dissepiments arid some hymenial elements, were examined. In the Cretaceous specimen, Quatsinoporites cranhamii sp. nov., pores are round to elliptical, three per mm, and 130-540 µm diam. Dissepiments consist of narrow, simple septate, hyphae. Neither basidia nor basidiospores are present, but acuminate hymenial cystidia, up to 54 µm in length, are common. The Eocene specimen, Appianoporites vancouverensis sp. nov., has a pore density of six per mm and pores are 130-163 µm in diam. Dissepiments consist of narrow, simple septate, thin-walled hyphae. Neither basidia nor basidiospores are present, but acuminate, thick-walled hymenial cystidia, up to 32 µm in length, are common. The poroid hymenophore is a characteristic of a number of extant basidiomycete taxa, including the Boletales, Polyporales and Hymenochaetales. It is unlikely that the fleshy, ephemeral, terrestrial basidiomata of the Boletales would be preserved in a marine environment, and thus the specimens are interpreted as belonging to basidiomycete lineages, with persistent, leathery or corky basidiomata. The simple septate hyphae, the minute pores and presence of cystidia most closely resemble taxa of the Hymenochaetales. These fossils unequivocally push back the minimum age of homobasidiomycetes and extend their paleogeographical range. [ABSTRACT FROM AUTHOR]

Previously only one specimen of springtail (Collembola) has been described worldwide from the Cretaceous. The present work reports the results of an examination of seventy-eight collembolan specimens from Canadian Upper Cretaceous amber. Sixty-three specimens have been identified at the generic level, none of which belongs to extant genera. All are placed within eight newly erected genera. Most of these specimens belong to a single new genus, Protoisotoma, of the family Isotomidae. Also included are members of the broadly construed families Sminthuridae, Neanuridae, and Tomoceridae. Re-examination of the type of Protentomobrya reaffirms its separate familial status. One additional specimen of an undescribed genus is placed in a new family. These data support a probable extinction of the Canadian arboreal Collembola fauna at the end of the Cretaceous. [Copyright &y& Elsevier]

The Lesueur landslide occurred on 3 September 1963 on the outside of a meander of the North Saskatchewan River in northeast Edmonton. The displaced volume was 0.76 Mm[sup 3] of Pleistocene deposits and underlying Upper Cretaceous mudstones. The trigger of the landslide is believed to be accelerated erosion of the slope toe caused by dumping of mine waste on the inside of the meander. Surveys in 1964, 1971, 1992, 1995, 1997, and 1998 have documented continued slope movements. The main scarp grew in height from 7.5 m on 4 September 1963 to 13.9 m in 1995 but retrogressed only 3 m. The displaced material extended up to 24 m into the North Saskatchewan River. When the forward motion of the passive block of the translational slide ceased to be driven by the sinking of the active block, river erosion caused rotational sliding of the displaced material on the surface of separation.Key words: landslide, Edmonton, Cretaceous, mudstone, erosion, North Saskatchewan River.Le glissement de Lesueur s'est produit le 3 septembre 1963 sur l'extérieur d'un méandre de la rivière North Saskatchewan au nord est de Edmonton. Le volume déplacé était de 0,76 Mm[sup 3] de dépôts du Pléistocène et d'argilites sous-jacents du Crétacée supérieur. On croit que le facteur déclencheur du glissement est l'érosion accélérée du talus causée par le déversement de résidus miniers à l'intérieur du méandre. Des relevés en 1964, 1971, 1992, 1995, 1997, et 1998 ont documenté des mouvements continuels du talus. La principale cicatrice s'est accrue en hauteur de 7,5 m le 4 septembre 1963 à 13,9 m en 1995, mais a rétrogressé de seulement 3 m. Lorsque le mouvement vers l'avant du bloc de butée du glissement de translation résultant de l'enfoncement du bloc de poussée a cessé de se produire, l'érosion de la rivière a causé un mouvement de glissement en rotation du matériau déplacé sur la surface de séparation.Mots clés : glissement, Edmonton, Crétacée, argilite, érosion, rivière North Saskatchewan.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]