the kashkan formation (paleocene to middle eocene), consists of conglomerate, sandstone, and siltstone in the zagros folded zone, southwest iran. type of the sedimentary facies, architectural elements and trace fossils show that kashkan deposits were formed in a low sinuosity braided stream system, with north to south flow direction. the formation displays coarsening-upward succession reflects ...

early triassic carbonate ramp sediments of the lower part of the elika formation are known as vermicular limestone. in the moro mountain, northwest iran, the vermicular limestone includes bioturbated dolomitic mudstone, bioclastic packstone and grainstone, algal calcirudite and intraclastic grainstone. these sediments accumulated in their lower part in open marine subtidal and shoal environment...

BACKGROUND The Green River Formation (early Eocene, about 42-53 Ma) at and near Fossil Butte National Monument in Wyoming, USA, is world famous for its exquisitely preserved freshwater teleost fish in the former Fossil Lake. Nonetheless, trace fossils attributed to fish interacting with the lake bottom are apparently rare, and have not been associated directly with any fish species. Here we int...

A recent description and analysis of an imprint fossil from the Carboniferous concluded that it was made by a mayfly landing in sediment at the edge of water. Here, I reanalyze that trace fossil and supply experimental evidence regarding wing traces and behavior. The thorax of the trace maker lacked structures characteristic of mayflies, but closely matches a modern neopteran insect family (Tae...

The increase in trace fossil diversity across the Neoproterozoic-Cambrian boundary often is presented in terms of tabulations of ichnogenera. However, a clearer picture of the increase in diversity and complexity can be reached by combining trace fossils into broad groups defined both on morphology and interpretation. This also focuses attention on looking for similarites between Neoproterozoic...

Bone remodelling is a crucial biological process needed to maintain elemental homeostasis. It is important to understand the trace elemental inventories that govern these processes as malfunctions in bone remodelling can have devastating effects on an organism. In this study, we use a combination of X-ray techniques to map, quantify, and characterise the coordination chemistry of trace elements...

An invertebrate ichnoassemblage from the Moenkopi Group (Spathian Ankareh Formation) at Diamond Creek in north-central Utah consists of Gordia marina Emmons, Helminthopsis hieroglyphica Wetzel and Bromley and irregular networks similar to Unisulcus. This is the first record of Gordia and Helminthopsis from the Moenkopi Group. This low diversity ichnoassemblage, consisting of simple grazing trac...

The Cambrian radiation of complex animals includes a dramatic increase in the depth and intensity of bioturbation in seafloor sediment known as the 'agronomic revolution'. This bioturbation transition was coupled with a shift in dominant trace fossil style from horizontal surficial traces in the late Precambrian to vertically penetrative trace fossils in the Cambrian. Here we show the existence...

The trace fossil Gyrochorte is common in Upper Jurassic siliciclastic rocks of the Kachchh Basin, western India. In the Kimmeridgian Katrol Formation, Gyrochorte comosa Heer, 1865 is tied to storm-generated fine-grained sandstones and exhibits an internal structure composed of double arches in cross-section, confirming the three-dimensional nature of the trace fossil and its interpretation as p...

The trace fossil Trichichnus is proposed as an indicator of fossil bioelectric bacterial activity at the oxic-anoxic interface zone of marine sediments. This fulfils the idea that such processes, commonly found in the modern realm, should be also present in the geological past. Trichichnus is an exceptional trace fossil due to its very thin diameter (mostly less than 1 mm) and common pyritic fi...