Concentrically rolled-up silty mudrock laminae, 1–2 mm thick, are found in the uppermost of four, 40–110 cm thick interdune beds within a thick aeolian succession of the c. 1.8 Ga Makgabeng Formation, Waterberg Group, South Africa. These curved laminae are analogous to previously described “roll-ups,” biogenic structures generally ascribed to soft-sediment deformation or desiccation of microbial mats overlying either carbonate or siliciclastic sediments, within shallow- to deep-marine paleoenvironments. The Makgabeng roll-ups are thought to reflect desiccation of a microbial mat, followed by resedimentation of cohesive, discrete, curled mat fragments. Their alignment is considered to be the result of an extreme precipitation event. The significance of the South African example of roll-ups is that they appear to have formed within a fully terrestrial paleoenvironment, in one of the oldest known Precambrian deserts. Thus, they represent the oldest evidence for microbial colonisation of a terrestrial setting.

Brachiopod spines have been interpreted as a mechanism that enables the organism to rest on soft substrates by distributing shell mass over a greater area. This hypothesis is based on an arrangement in which spines are long, strongly curved, few in number, and generally restricted to the pedicle valve. However, other spine geometries also are prevalent, and the assumption that all arrangements functioned similarly may be unwarranted. Spinatrypa and Praewaagenoconcha, an atrypide and a productide, respectively, are genera of spinose brachiopods from the Upper Devonian Java Formation of New York. Although these genera belong to different subclasses, they have a similar spine geometry consisting of hundreds of thin, short, sub-perpendicular (to shell surface) spines, arranged concentrically on both valves.

Population densities of articulate brachiopods were obtained from six localities of the Java Formation along an offshore-onshore gradient. Individuals were counted relative to surface area of the bedding planes. There are moderate, but highly significant, correlations between grain size and abundance of each spinose taxon, and the greatest mean densities of both Praewaagenoconcha and Spinatrypa occur in coarse sandstones. Although both genera have broad environmental ranges, peak mean abundances of Praewaagenoconcha and Spinatrypa are in platform margin and outer platform facies. All of these distributions are statistically distinguishable (χ ² test, p < 0.0001) from the distribution of non-spinose taxa within the Java Formation.

These results are inconsistent with the hypothesis that all spine geometries served as soft substrate supports. Alternative functional hypotheses for this spine geometry include (1) anchorage in high energy habitats, and/or (2) protection from predation.

Three localities in the Chinle Formation (Late Triassic), Petrified Forest National Park (PEFO), Arizona, provide insights into the paleoenvironments frequented by primitive North American theropods. At the Dinosaur Wash locality, an undetermined theropod is preserved in paleosols that indicate a transition from wet to dry conditions on the floodplain. Coelophysis bauri remains from the Dinosaur Hill locality are preserved in a filled channel scour. The paleosols at this locality contain carbonate nodules intimately associated with Fe and Mn oxides, indicative of alternating alkaline/acidic conditions around roots in response to a semi-arid climate with strong seasonal precipitation. At the Dinosaur Hollow locality, Chindesaurus bryansmalli is preserved in a setting similar to those encountered at Dinosaur Hill. The paleosols exhibit vertic features, such as pseudoanticlines, and are indicative of water-deficit periods during the year.

The most complete theropod remains at PEFO are predominantly preserved in distinctive blue-colored paleosol horizons showing depletion in iron and aluminum, and exhibiting features such as localized Fe concentrations and mottling. These are interpreted as A-horizons of redoximorphic paleosols developed in wet areas of the floodplain where the degree of water saturation fluctuated.

Preservational conditions of PEFO theropod localities indicate they are time-averaged attritional mortality assemblages representative of contemporaneous organisms. Comparison of these localities to the well-known Ghost Ranch, New Mexico, Coelophysis quarry reinforces the idea that the quarry represents unique preservational conditions.

Rhodoliths from the Late Pleistocene Ironshore Formation in the Crystal Harbour area on the western part of Grand Cayman, which are up to 14 cm long, are characterized by thick cortices that were constructed around nucleii formed primarily of coral or bivalve fragments. Two different communities of encrusting organisms constructed the cortices. The thin inner zone (average ∼2 mm thick) was formed by the Coralline Community which was dominated by Lithoporella, Lithophyllum and Neogoniolithon, along with fewer Peyssonnelia rubra, Hydrolithon reinholdi, Lithothamnium, and Porolithon. The thick outer zone (up to 60 mm thick) is dominated by Peyssonnelia rubra, along with scattered coralline algae, serpulid worms, foraminifera, and bivalves.

The Cayman rhodoliths grew in narrow zones surrounding large patch reefs that developed in water less than 14 m deep. The sciaphyllic Peyssonnelia rubra may have grown beneath a non-calcareous fleshy alga that covered the encrusting organisms. The change from the Coralline Community to the Peyssonnelid Community, evident in every rhodolith, probably represents a developmental succession in the encrusting communities.

The coral reef in Tutum Bay, Ambitle Island, Papua New Guinea, is exposed to the vigorous discharge of hydrothermal fluids (up to 98°C). This study investigates eight Porites lobata samples that were collected throughout the area of active venting at varying distances from vent sites. A sample from a “non-hydrothermal” coral (C-29), collected 10 km north of Tutum Bay, was analyzed for comparative purposes.

Density banding is moderately well developed in these corals and subannual bands are common. For corals from Tutum Bay, δ¹³C ranges from −4.5 to −1.0‰ and δ¹⁸O from −6.0 to −3.8‰, which are relatively depleted values for shallow water Porites. The comparison sample, C-29, has δ¹³C values ranging from −1.8 to −0.5‰, and δ¹⁸O values of −5.4 to −4.6‰. Concentrations of As, Co, Cr, Ga, Ge, Mo, Nb, Ni, Pb, Rb, Se, W, Y and Zr were always below their respective proton probe detection limits. Ba, Br, Cu, Fe, Mn, and Zn were detected in some samples. Sr was detected in all samples and concentrations ranged from 6970 to 8240 ppm. Strontium isotope ratios of selected samples (C-5, C-8 and C-29) are very close to seawater, but Tutum Bay corals (C-5 and C-8) have lower ⁸⁷Sr/⁸⁶Sr values than the “non-hydrothermal” sample (C-29).

The observed isotope patterns indicate that the hydrothermal input into Tutum Bay influences the physico-chemical conditions in the surrounding coral reef. Tutum Bay Porites lobata show distinctly different δ¹³C and ⁸⁷Sr/⁸⁶Sr records when compared to the “non-hydrothermal” sample and other corals from Papua New Guinea and elsewhere. Direct and indirect synergistic effects, including temperature, isotopic and chemical composition of vent fluids and the influence of pCO₂ on the expression of photosynthetic and kinetic stable isotope fractionation factors, are the most likely explanation for the “hydrothermal” signal seen in these corals. The δ¹⁸O values are significantly correlated with the estimated amounts of hydrothermal exposure.

To what extent does ichnological diversity (the number of distinctive trace fossil morphologies) serve as a proxy for zoological diversity (species richness of trackmakers in the living fauna) in footprint assemblages made by terrestrial lower vertebrates? This question was investigated in a study of body form and trackway features of monitor lizards (varanids) from the Western Australian desert. Body-shape parameters deemed likely to affect trackway pattern of seven varanid species were measured. These lizards differ in average adult size, but there is considerable size overlap between adults of small-bodied species and juveniles of large-bodied species. Although subtle species differences in body form were detected, these were largely swamped by intraspecific variability. Furthermore, the most distinctive features in which trails of monitor species differ reflect interspecific differences in foraging behavior rather than anatomical differences, and are features that would be difficult or impossible to recognize without actually capturing the trackmaker. These observations provide empirical support for the widely held belief that trace fossil diversity commonly under-represents zoological diversity. The degree to which this is so is likely to be influenced by trackmaker body size and metabolic physiology.

Macro-endoliths in coral skeletons on reefs in Phuket, South Thailand, and South Male Atoll, Republic of the Maldives, could be separated into live- and dead-coral varieties, which had different origins and created different structures in the host skeletons. Dead coral surfaces were bored by active endoliths (euendoliths), which used mechanical and chemical means to create complex, branched and sinuous cavities that cross-cut the growth structure of the coral skeletons. Living coral was attacked mainly by passive endoliths (paraendoliths and cryptoendoliths) that embedded themselves in the live tissue and allowed the coral skeleton to grow up around them, creating straight, simple holes that paralleled the growth direction of the coral. The association of euendoliths with dead coral surfaces and para- and cryptoendoliths with live coral surfaces allows the interpretation of the relative relief of fossil bored coral colonies above soft sediment, and the relative length of time they were exposed to circulating seawater prior to burial.