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A set of 204 Cretaceous and Paleocene samples from Holes 959D, 960A, 960C, 961A, 961B, 962B, 962C (barren), and 962D of the Côte d'Ivoire-Ghana Transform Margin (Leg 159) were palynologically analyzed. Three main types of palynofacies were distinguished. The first type indicates strong terrestrial depositional conditions and characterizes lithologic Unit V of Hole 959D, Subunit VB and most samples of Subunit VA of Hole 960A, and Unit III of Holes 961A and 961B. The presence of some stratigraphically significant spores and pollen grains indicates a late Barremian-middle Albian age for Unit V of Holes 959D and 960A, and a middle Albian age for Unit III of Holes 961A and 961B. The second type of palynofacies reveals mixed terrestrial and marine depositional conditions. This type was observed in Subunit IIC of Hole 962B and Unit III of Hole 962D. The occurrence of stratigraphically significant spore, pollen grain, and dinoflagellate cyst species argues for a Cenomanian age for these units in Holes 962B and 962C. The third type of palynofacies indicates clearly marine environmental conditions. This type is found in Subunit IVA and Unit III of Hole 959D, where highly diversified dinocyst assemblages (73 species, among them the following three new ones: Spiniferites bejuii n. sp., Spiniferites sp. G, and Xenascus ghanaensis n. sp.) were identified. Based on the presence of several Late Cretaceous and Paleocene markers, precise age determinations are possible for this part of Hole 959D: Subunit IVA and the lowermost cores of Unit III are probably early Coniacian in age; subsequent cores of Unit III are Santonian, Campanian, Maastrichtian, Danian and, at the top, late Thanetian in age.

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It has long been assumed that photosensitivity in echinoderms is mainly related to diffuse photoreception mediated by photosensitive regions embedded within the dermis. Recent studies, however, have shown that some extant echinoderms may also display modified ossicles with microlenses acting as sophisticated photosensory organs. Thanks to their remarkable properties, these calcitic microlenses serve as an inspiration for scientists across various disciplines among which bio-inspired engineering. However, the evolutionary origins of these microlenses remain obscure. Here we provide microstructural evidence showing that analogous spherical calcitic lenses had been acquired in some brittle stars and starfish of Poland by the Late Cretaceous (Campanian, ~79 Ma). Specimens from Poland described here had a highly developed visual system similar to that of modern forms. We suggest that such an optimization of echinoderm skeletons for both mechanical and optical purposes reflects escalation-related adaptation to increased predation pressure during the so-called Mesozoic Marine Revolution.

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Although crinoids appear not to have been involved in the great change in diversity at the Cretaceous-Paleogene (K-Pg) boundary extinction event, it has been assumed that representatives of order Roveacrinida became extinct during this time. Well-preserved fossils from the Danian (early Paleocene) of Poland demonstrate that these crinoids survived into the earliest Cenozoic. This fi nd merits the qualifi cation of this order as a "dead clade walking."

The Cretaceous Period (145–66 Ma) consisted of several oceanic anoxic events (120–80 Ma), stimulated by global greenhouse effects. The Oceanic Anoxic Event 2 (OAE2) occurred worldwide from the late Cenomanian to the early-middle Turonian, causing a significant faunal turnover, mostly in marine biota, pushing some species to the brink of extinction. Some organisms also underwent morphological changes, including reduction in size. This anoxic event drove other changes—e.g., in habitats or strategy of life. We show that stalkless crinoids (comatulids) from the Turonian of Poland adapted to unfavorable environmental conditions by reducing their body size. Furthermore, at the moment when environmental factors became favorable again, these crinoids regained their regular (pre-event) size. This phenomenon likely illustrates the so-called dwarfing mode of the Lilliput effect.