The stable carbon isotopic composition (δ¹³C) of fossil leaves is a simple and common measurement that provides information about paleophysiology, paleoecology, and paleoclimate. Variance in δ¹³C is typically assessed across leaves; comparatively little is known about variance within leaves, a potential source of unquantified uncertainty. Here we systematically analyze the spatial patterns of bulk δ¹³C in fresh leaves of 10 tree species (two leaves per species; 21 or 22 analyses per leaf). We find that samples containing midvein tissue are markedly higher in δ¹³C than non-midvein tissue from the same leaf (median = +0.85‰), with samples containing only midvein tissue offset by as much as +3.01‰. The non-midvein samples are less variable—the typical range within a single leaf is <1‰—and do not show any consistent spatial patterns. In cases where whole fossil leaves cannot be analyzed, we recommend sampling as many randomized areas without major veins as is feasible.

Although vertebrate carcasses––particularly those assigned to fishes––are abundant in the fossil record, the literature rarely mentions fishes as trace producers. Herein we present evidence that was possibly overlooked in previous studies. Study of more than 100 large, shallow, teardrop-shaped, imprints that are aligned, with few overlapping each other, from early Paleozoic (probably Silurian based on trace fossils) outcrops in western Gondwana (southeastern Argentina), are identified as the oldest example of shoaling behavior. To understand the nature of the behavior, we considered analog (vertebrate and invertebrate) extant and extinct taxa. We compare and discuss the superficial similarities with certain traces, in particular Selenichnites isp. and erect a new ichnotaxon, Raederichnus dondasi isp. nov. for the Argentinian material. We report for the first time from the Balcarce Formation Psammichnites isp., in association with Herradurichnus scagliai, both forming minor components of the ichnoassemblage. Raederichnus dondasi and the accompanying traces are preserved in three-dimensional dunes, developed in a tide-dominated shallow marine environment. Given the morphological resemblance, and paleoecological context, we consider that Raederichnus dondasi might have been produced by fish while “resting”. Finally, this aggregation of trace fossils suggests shoaling related to feeding or breeding on the shallow marine bottom surface.

A new specimen from a plant locality in the Morrison Formation of southeastern Utah exhibits characters suggestive of a small bromalite, possibly from a fish or semi-aquatic mammal. The specimen consists of a cluster of small bones, most referable to lissamphibians, including elements of at least one small frog (possibly a tadpole) and possibly the smallest reported salamander specimen from the formation. Chemical and taphonomic characters suggest that the specimen is a regurgitalite, the first from both the Morrison Formation and the Jurassic of North America. The lissamphibian material in the bromalite represents the southernmost likely occurrence of frogs and salamanders in the formation. The possible salamander material may represent a rare juvenile rather than a new taxon, and it is morphologically more similar to Valdotriton and Comonecturoides than it is to Iridotriton. The frog material is similarly unidentifiable to specific taxon.

Recent research has shown that sedimentological information in barrier-island settings may provide more detailed interpretations of some past coastal environments than interpretations based upon foraminifera. This research investigates whether targeted documentation of modern foraminifera in specific coastal environments can result in higher resolution micropaleontology-based paleoenvironmental reconstructions. Bear Island, North Carolina, characterized by little human disturbance, was chosen for detailed documentation of foraminifera in modern barrier-island-related environments. Modern sediments in all subenvironments were predominantly siliciclastic (< 30 % clastic carbonate debris) in composition: clastic carbonate allochems (e.g., mollusk shell fragments, echinoid spines) were admixed with fine- to medium-grained quartz sand. The hypothesis that modern foraminiferal assemblages of 26 modern coastal subenvironments can be distinguished based upon their foraminiferal assemblages was tested by discriminant analysis and resulted in the recognition of four environmental supergroups: shoreface, ebb-tidal delta, flood-tidal delta/inlet channel, and “barrier-combined” (foreshore, washover, dune, sandflat, spit, longshore bar, and trough). Holocene paleoenvironments represented by foraminiferal assemblages in 16 vibracores collected from the modern inner shelf, shoreface, ebb-tidal delta, and inlet environments of Bogue Banks, immediately adjacent to Bear Island, were interpreted, via discriminant analysis, based upon the modern dataset. Holocene and modern foraminiferal assemblages were similar but variations in species abundance and species diversity allowed for alternative paleoenvironmental classification of core samples at varying levels of probability. The methodology of this research is widely applicable to other coastal environments.