The Permian–Triassic transition was an important time for many marine groups, including echinoderms. However, the fossil record of ophiuroids through this interval is poorly understood. Recent discoveries in Lower Triassic rocks from northern Italy and western US suggest that ophiuroids were more common during this time than previously has been appreciated. Evidence from resting traces (Asteriacites lumbricalis) indicates that Early Triassic ophiuroids lived on fine-grained siliciclastic sediments in oxygenated, shallow-marine environments within storm wave base. No resting traces have been recorded from deeper and/or oxygen-restricted settings. However, following death and decay, ophiuroid skeletal elements sometimes were transported into offshore, low-oxygen environments. All known occurrences of Early Triassic ophiuroids fall within the paleotropics, but this is attributed to sampling bias. Articulated body fossils and their trace fossils are most common in latest Lower Triassic (Olenekian) rocks, but disarticulated ossicles occur throughout the Induan and Olenekian. At times and places, ophiuroids were the dominant marine benthos, carpeting the substrate in prodigious numbers. However, at other times, they also comprised minor components of diverse benthic assemblages, living alongside crinoids (Holocrinus), bryozoans, bivalves, gastropods, and brachiopods. Morphological comparison with extant ophiuroids suggests that all known Early Triassic taxa were small surface-dwellers.

During the geologic history of crinoids, many groups have modified their distal stems to function as anchors in soft sediments, but more so in the Paleozoic than in later times. Major strategies were passively implanting anchors, cirral root systems, coils, and stemless reclining. In Paleozoic roots, the stereom usually consists of crystallographically individualized ossicles, but articulations may be hidden by a tough cuticle that protected the living tissue of immersed parts and stiffened them with cortical stereom. Post-Paleozoic representatives produced similar anchoring structures by different fabricational pathways, including non-articulated root systems.

Abundant columns of Isselicrinus ariakensis occur in a limited interval of the Upper Eocene Sakasegawa Formation in western Japan. Most of these are several centimeters in length, but curiously they usually stand upright, perpendicular to the bedding plane of the mudstone, and occur as bundles of 2 to 10 columns, with their original distal parts oriented downward. Based on detailed observation of the modes of occurrence as well as on CT scanning of the specimens, a reconstruction of the presumed mode of life is presented. The individuals of Isselicrinus adopted a relay strategy in the muddy substrate, using pre-existing upright columns as anchorage. Similar upright columns of Isselicrinus are also found, or have been reported, from other Eocene and Miocene strata in Japan, Argentina, and Denmark, suggesting that these Isselicrinus adopted this specialized mode of life as an adaptation to muddy bottoms.

The Late Pennsylvanian Graissessac-Lodève basin is a small, fluvio-palustrine depocenter located in the southern part of the Massif Central (France). A taphonomic and sedimentologic study carried out in this area allows a reconstruction of Late Carboniferous vegetation in an intramontane context. The paleoecology of such limnic settings is poorly known, and this study permits detailed comparison with paralic basins for the first time. The Graissessac peat mires developed in abandoned fluvial channels, in floodplains, and above distal alluvial fans. The vegetation was dominated by monospecific stands of the arborescent lycopsid Sigillaria brardii, whereas the tree fern Psaronius occurred during the later stages of mire accretion. This is in contrast to coeval North American peat mires, which generally were dominated by tree ferns and pteridosperms throughout the mire profile. Stephanian floodplains and distal alluvial fans of the Graissessac-Lodève Basin were devoid of vegetation, with the exception of isolated thickets of sphenopsids that were composed of Calamites and Sphenophyllum. These plants were found growing in situ in the floodplain mudstones as well as in fine-grained sands of secondary channels. Parautochthonous foliage assemblages of ferns and pteridosperms found in floodplain mudstones represent the most diverse plant community. The plants supplying these remains were growing in exposed areas close to floodplains. Large logs attributed to cordaitaleans and monotypic assemblages of large Cordaites leaves were found in fluvial sediments, and suggest that the plants were riparian elements in the basin.

Sedimentary and palynofacies analysis, total organic carbon content (TOC), and palynology from a densely sampled, small, lignite-bearing succession of Late Miocene age at Badersdorf, SE Austria, were compared with modern wetland ecologies. From this, six hydrologically controlled palynofacies types and six associated paleo-plant habitats in an ancient wetland system were differentiated. The associated woody and herbaceous hinterland flora also were distinguished. At least four horizons with relatively high fusinite content have been preserved, indicating occurrence of paleo-wildfires in either the wetland or the hinterland. The palynofacies types were used to determine the taphonomic bias of the associated palynomorph assemblages, which, together with a comparison with modern wetland vegetation, led to differentiation of the paleo-plant habitats. The paleo-wetland was dominated mainly by Glyptostrobus-containing vegetation, and comprised clastic swamp forests with woody angiosperms, natural levee forests, fern- and Glyptostrobus-dominated organic swamps, freshwater marshes, and wet prairies. The occurrence of more than 40 herbaceous taxa at this locality indicates that the lowland vegetation was not composed of only different closed-forest types, but also of areas with herbaceous vegetation. The more zonal vegetation of the adjacent hinterland has been interpreted as a mix of Pinaceae and woody angiosperms with patches of more herbaceous xeric layers.

Few shell-crushing predators can excavate prey living deep within the sediment. Despite this infaunal refuge from predators, many deep-burrowing bivalves display a strikingly high incidence of shell damage when compared with species living at shallower depths. A non-predatory origin is necessary to explain this high incidence of injury. To evaluate the generality of this hypothesis, repair frequency (number of repairs per shell), along with position and geometry, were determined for 68 Neogene bivalve species from the US Atlantic and Gulf Coastal Plain, seven of which are classified as deep burrowers (>20 cm depth of sediment penetration). Panopea bitruncata, Panopea floridana, Panopea reflexa, and Panopea americana, which are among the deepest burrowers (up to 100 cm), have repair frequencies (2.8– 6.2) that are higher than any other species, while the value for Cyrtopleura costata (0.76) is exceeded only by semi-infaunal Atrina species (1.12). However, not all deep-burrowing species had such high incidences of damage. Two moderately deep-burrowing species (Anodontia alba and Tagelus plebeius; 20–50 cm) showed repair frequencies (0.04–0.30) that overlapped the range (0.001–0.52) for shallow-burrowing, semi-infaunal, and epifaunal species. Therefore, any generalizations about the relationship between depth of sediment penetrated and frequency of shell damage are inadvisable. Most scars on deep burrowers were not attributable to the direct activity of shell-crushing predators because: (1) injury occurred late in life when individuals were positioned in the safety of a deep burrow; (2) scar types consistent with a predatory origin were rare; and (3) scars frequently occurred on the anterior of the shell, which is least accessible to digging predators.

Analyses of predatory damage on subfossil hard parts can be used to document the trophic role played by species that were abundant prior to human impact even when pre-impact surveys are lacking or when predators have not left skeletal remains. Before upstream dams and water diversions, the bivalve Mulinia coloradoensis was the most common mollusk inhabiting the Colorado River Estuary. Today, only a small population has survived the environmental changes caused by reduction in the river's flow. When abundant, this species was a major source of food for predatory gastropods and crabs, as shown by the characteristic damage inflicted by these predators. Boreholes made by predatory gastropods were found in 23% of the 600 individuals sampled from shell accumulations that date from the era prior to upstream dams and diversions. Marginal shell damage characteristic of predatory portunid crabs was found in 27% of the individuals. Thirty-four percent of the individuals had damage from earlier attacks. Shells were tumbled to provide criteria to distinguish ante-mortem biological damage to the shell margin from post-mortem physical damage. Decline in the population of this prey species likely caused a decline in the populations of its predators and species higher in the food chain, prey-switching, or both effects. Restoration of river flow would increase populations of M. coloradoensis and species that depend on it for food, including commercially important crabs.