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Analysis of mushroom‐shaped rugose corals Schlotheimophyllum patellatum (Schlotheim, 1820) from the Silurian (Upper Visby Beds, Lower Wenlock, Sheinwoodian) of Gotland, Sweden, showed that they were colonized on both the upper (exposed) and lower (cryptic) sides by a variety of encrusting and boring (sclerobiont) biotas, represented by 10 taxa and at least 23 species. Bryozoans and microconchid tubeworms, the most abundant encrusters, dominated on the cryptic undersides of the corals, while the dominant endobionts responsible for Trypanites borings overwhelmingly dominated the exposed surfaces. Except for cnidarian sphenothallids, which were exclusive colonizers of the underside of only one coral host, no other encrusters could be referred to as obligate cryptobionts. Because the upper surface of these corals was likely covered by soft‐tissues during life, in specimens lifted off the sea‐floor sclerobionts must have settled on the cryptic sides first. They could colonize the upper side only after the coral's death, unless it was covered by sediment as could be the case in some flat specimens. With time, the space on the underside of the coral skeleton may have progressively been filled by sediment as well, precluding further colonization by sclerobionts. In that respect, the colonization patterns of these corals by encrusters and borers were controlled by the complex interplay of environmental factors, sclerobiont dynamics and coral growth in a given Silurian habitat. Compared with Silurian stromatoporoid hosts, the sclerobiont diversity and abundance noted on the Schlotheimophyllum corals may be regarded as representative for the Silurian as a whole. [ABSTRACT FROM AUTHOR]

The article discusses the predator-prey relationship in the Middle Jurassic period, citing the evolutionary changes of echinoids. It mentions that predation and biotic interactions are fundamental factors of organismal evolution. It notes the crucial ecological role of predators in controlling population densities, species distributions, morphology, body size, and life habits.

A rich and diverse assemblage of arthropods and non-biomineralized macroalgae occurs in the Upper Devonian marine deposits of the Holy Cross Mountains, central Poland. The phrase Kowala Lagerstätte is herein proposed for the fossil-bearing deposits confined to the lower Famennian marly shale and limestone succession of the famous Kowala Quarry. The arthropod fauna is represented by phosphatic exoskeletal remains that still preserve the fine micro-ornamentation of the cuticle. The fauna includes crustaceans and crustacean-like taxa such as thylacocephalans, phyllocarids and angustidontids (in order of abundance). The non-biomineralized algae, represented by at least three morphotypes, occur as carbonaceous compressions of their thalli while still preserving fine details including bundles of thin tubular projections. Although their general appearance is reminiscent of some Early Palaeozoic non-calcified Dasycladales algae, their true taxonomic position is still uncertain. Lithology, as well as faunal and phytoplankton content point to a pelagic sedimentary environment. Impoverished benthic fauna, sediment lamination and geochemical signatures indicate at least periodic bottom-water dysoxic to anoxic conditions. Thus, the preservation of arthropod cuticle and non-calcified algae was primarily governed by oxygen-deficient bottom waters that prevented bioturbation and scavenging during their burial. [ABSTRACT FROM AUTHOR]

The Frasnian-Famennian extinction witnessed the global devastation of both level-bottom and reef communities in low latitudes. Marine extinctions in offshore level-bottom communities are associated with two widespread, transgressive, anoxic 'Kellwasser Events' that support an anoxia-extinction link. Typical Kellwasser facies of bituminous limestones and shales are not obviously recorded in shallow-water settings, and thus, it is unclear whether anoxia played a role in reef losses. We evaluate geochemical, petrographic and facies evidence for oxygen restriction from an extremely shallow-water carbonate platform in Alberta. Sequence stratigraphy places the Frasnian-Famennian boundary at a sequence boundary that tops a laminated mudstone and interrupts carbonate platform deposition. Two transgressive pulses have been identified, one of which is associated with the second, major transgression of T-R cycle IId of the Devonian eustatic sea-level curve. Geochemical proxies indicate that these transgressions were accompanied by influx of dysoxic or anoxic waters. Organic carbon and U enrichment in the Frasnian, particularly just below the Frasnian-Famennian boundary, points to episodic dysoxic conditions that probably persisted into the basal Famennian and were coincidental with the global Upper Kellwasser Event. This study provides the first evidence for the smoking gun of an anoxia-driven extinction in very shallow waters, implicating this potent killer in the demise of the Devonian reefs. [ABSTRACT FROM AUTHOR]

The article discusses a report of the cidaroid echinoid remains in Bajocian-Bathonian vertebrate regurgitates from southern Poland. It elaborates the findings and tackles its broader significance for the ecology and evolution of echinoids. It also provides a source of data for the reconstruction of food webs in the fossil record and is important as evidence for the role of predation in echinoderm evolution.

Filipiak, P. & Zatoń, M. 2010: Plant and animal cuticle remains from the Lower Devonian of southern Poland and their palaeoenvironmental significance. Lethaia, Vol. 44, pp. 397-409. Assemblages of plant and arthropod remains are reported from the Lower Devonian clastic deposits of the Upper Silesian and Małopolska blocks in southern Poland. Most of the plant and animal remains are palynologically dated as Pragian-Emsian/Eifelian. The plant material comprises higher plant cuticles with stomata classified as Drephanophycus and Sawdonia, and more enigmatic remains (nematophytes) classified as Nematothallus, Cosmochlaina and tubular banded tubes. They are associated with abundant and diverse miospores. Animal remains consist of eurypterid respiratory organs, the morphology of which may presumably point to their advance physiological properties, and cuticular remains of eurypterid and probably scorpion origin, as well as some remains of unknown affinity. The presence of such mixed assemblages in the Lower Devonian of Poland indicate marginal-marine and/or alluvial environments spreading in the southern margin of the Old Red Continent. The dominance of land-derived plant remains and simultaneous scarcity of marine acritarchs indicate that the environment was very weakly influenced by marine conditions. If nematophytes were really related to extant liverworts, as suggested by some workers, they, together with the other associated spore-producing plants, may strongly indicate moist environmental conditions, which may have offered suitable habitats for temporary eurypterid migrations onto land. □ Cuticles, eurypterids, Lower Devonian, nematophytes, Poland, spores. [ABSTRACT FROM AUTHOR]

Distinct faunal aggregates are described from the Middle Jurassic (uppermost Bajocian/lowermost Bathonian and Middle Bathonian) clay deposits of Częstochowa area, south-central Poland. These aggregates are composed of molluscs (scaphopods, gastropods, bivalves, ammonites and belemnites), articulate brachiopods and echinoderms (asteroids, crinoids and echinoids). A large percentage of the fossils, especially bivalves, are fragmented, but some fossils are complete. Although most of the fossils are crushed and fragmented, they are still identifiable to at least the genus level. Thorough statistical analysis of taphonomic features indicates that the preservation of asteroid marginal plates is distinct from the ossicles derived from the host clays. The high frequency of bite marks and the good state of preservation suggest that the accumulations are the products of predation activities and most probably are the effect of regurgitation. Taking into account the rich and diverse fauna, the predator was a bottom-feeding generalist. Possible predators include palaeospinacid sharks, a tooth of which was collected from the same bedding surface, but not associated with regurgitated remains. Although the bite marks on the asteroid ossicles point to sharks as potential producers of regurgitates, other vertebrates, like durophagous pycnodontiform fish, cannot be excluded. [ABSTRACT FROM AUTHOR]

The article focuses on the interpretation of Nectocaris pteryx, a Middle Cambrian fossil as cephalopod. It states that the Nectocaris pteryx which is interpreted as a chordate or an arthropod is the oldest relative of cephalopod. It says that a cephalopod will be called as a cephalopod based on its siphuncle that could have originated on its pelagic life style from larvae to adults. Moreover, the Nectocaris pteryx is not consistent with the logical sequence of events in the cephalopod evolution.

The article focuses on the spread of encrusting organisms in marine environments. It says that the organisms are represented by phyla which adheres hard substrata from tiny foraminiferans to large oysters. It states that microconchids are tiny encrusters which appeared in late Ordovician period and possess calcitic and spirally coiled tubes similar to the polychaete genus Spirorbis. Furthermore, the microconchids are originally named Spirorbula and belong to the genus Punctaconchus.