We present sedimentological comparisons and stratigraphical correlations of the Jurassic and Cretaceous epicontinental shelf deposits of Svalbard and updated descriptions of the shallow‐marine North Greenland sediments of East Peary Land and Kronprins Christians Land (Kilen). The Callovian to Volgian Agardhfjellet Formation of Svalbard is correlated to the lower part of the Ladegårdsåen Formation on East Peary Land, and to the Birkelund Fjeld, Splitbæk, and Kuglelejet formations of Kronprins Christian Land (Kilen). The Berriasian to Hauterivian Rurikfjellet Formation (Svalbard) correlates with the Dromledome and Lichen Ryg formations from Kilen and the middle part of the Ladegårdsåen Formation from East Peary Land. The Galadriel Fjeld Formation from Kilen and the upper part of the Ladegårdsåen Formation (East Peary Land) are comparable to the Helvetiafjellet and Carolinefjellet formations of Svalbard. These comparisons between Svalbard and North Greenland are combined with stratigraphical information from neighbouring regions in palaeogeographical reconstructions. Five selected time slices are presented within a setting of the most recent plate tectonic reconstructions for the area.

In the North Atlantic, Laurentia–Eurasia break-up commenced in the Late Carboniferous, largely following the structural grain of the Caledonian Fold Belt. However, in the Arctic region, a 45° offset in the plate boundary between North Greenland and Svalbard was determined by a number of pre-Caledonian fundamental faults in North Greenland. As a result, this segment of the plate boundary experienced significant episodes of combined transtension and transpression, in part controlled by the movement of a temporarily independent Greenland Plate. Late Permian–Mesozoic deposits in the North Greenland Wandel Sea Basin record the plate-boundary history along this offset, in our view in a series of at least 20, variously disturbed, pull-apart basins, most of which can be assigned to four major episodes of pull-apart basin formation. The direction of the pre-existing fundamental faults, in combination with the regional variation in rock properties of both the basin floor and basin fill, explains the marked differences in tectonic style recorded along the plate boundary.

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The relative numbers of sexually and asexually recruited colonies and the proportion of brooding zooids were determined in 26 species of cheilostome bryozoans of Late Cretaceous and Early Tertiary ages. Asexual reproduction seems to be much more widespread than previously realized, although its relative importance is related to growth habit. Arborescent species of these fossil assemblages reproduce mainly asexually via fragmentation; encrusting species reproduce sexually via motile larvae. Free-living species use both methods; some reproduce sexually, whereas other species have enhanced the ability to break and reproduce predominantly asexually. Mode of reproduction was stable over a period of 3 m.y. in all species except the vinelike Columnotheca cribrosa. In this species both the proportion of asexual recruits and brooding zooids varied in accord with environmental parameters. In all cases populations dominated by asexual propagation had a significantly lower proportion of brooding zooids than populations dominated by sexual propagation.