understand biotic recovery in both the body and trace fossil records of the Early Triassic, almost no focus has previously been given to analyzing patterns in ecosystem engineering complexity as a result of the extinction drivers. Bioturbation is a key ecosystem engineering behavior in marine environments, as it results in changes to resource flows and the physical environment. Thus, the trace fossil record can be used to examine the effect of the end-Permian mass extinction on bioturbating ecosystem engineers. We present a dataset compiled from previously published literature to analyze burrowing ecosystem engineering behaviors through the Permian- Triassic boundary. We report two key observations: first, that there is no loss in bioturbation ecosystem engineering behaviors after the mass extinction, and second, that these persisting behaviors include deep tier, high-impact, complex ecosystem engineering. These findings suggest that while environmental conditions may have limited deeper burrowing, complex ecosystem engineering behaviors were able to persist in the Early Triassic. Furthermore, the persistence of deep tier bioirrigated three-dimensional network burrows implies that benthic biogeochemical cycling could have been maintained at pre-extinction states in some local environments, stimulating ecosystem productivity and promoting biotic recovery in the Early Triassic.

Crucello, J., Pierone, D.V., Hantao, L.W., 2020. Simple and cost-effective determination of polychlorinated biphenyls in insulating oils using an ionic liquid-based stationary phase and flow modulated comprehensive two-dimensional gas chromatography with electron capture detection. Journal of Chromatography A 1610, 460530.

http://www.sciencedirect.com/science/article/pii/S0021967319309252 In this article we describe a method using flow-modulated comprehensive two-dimensional gas chromatography with electron capture detector (FM - GC×GC - ECD) for the determination of polychlorinated biphenyls (PCBs) in complex transformer oils bypassing the need for sample preparation. A two-fold improvement in method development was attained. First, the solvation parameter model (SPM) was used to guide column selection. A highly cohesive ionic liquid-based phase (low l system constant), namely 1,12- di(tripropylphosphonium)dodecane bis(trifluoromethanesulfonyl)imide, was used in the primary stage leading to negligible retention of interfering aliphatic hydrocarbons, which are eluted in the first upper quadrant of the chromatogram. The resulting separation space was used to resolve the critical class of compounds, namely, PCBs and polyaromatic hydrocarbons. Second, a unique combination of column geometries and phase ratios enabled highly efficient reverse fill/flush flow modulation using very low pressure for auxiliary gas flow. The proof of concept method described herein exhibited linearities ranging from 0.990 to 0.994, limits of quantitation (LOQ) from 2.23 and 6.85 µg mL-1, precision below 5% relative standard deviation (RSD), and accuracy from 84.2% to 108.9% showcasing the potential of FM - GC×GC for routine analysis.

Cui, L., Liu, W., Zhang, X., 2020. Phosphatized microbial fossils from the lowest Cambrian of South China and their ecological and environmental implications for the Kuanchuanpu biota. Precambrian Research 338, 105560.

http://www.sciencedirect.com/science/article/pii/S0301926818306715 The early Cambrian Fortunian-age Kuanchuanpu Formation exposed in the northwestern margin of South China is well known for recording unique aspects of the 'Cambrian explosion', notably the coexistence of Small Shelly Faunas and soft-bodied meiofaunas. Although microorganisms, both primary producers and decomposers, are important biotic components of marine ecosystems in which they play a crucial ecological role in matter cycling and energy flow, Cambrian microbial records have not been brought into attention so much as their intimately associated faunas. To extend these records here we report a diverse assemblage of cellularly preserved microbial fossils from cherts of the Kuanchuanpu Formation. Nine species comprising six genera and two undescribed taxa have been identified. Among taxa interpreted as primary producers, are Gloeodiniopsis and unnamed form B that are morphologically analogous to coccoidal chroococcacean Megathrix Siphonophycus , cyanobacteria, and and to filamentous oscillatoriacean cyanobacteria. In contrast co- Endoconchia occurring members of endobiotic ? are inferred to be biodegraders. The high preservational fidelity of this microbial assemblage is here documented by use of optical microscopy, scanning electron microscopy, energy dispersive spectrometry, back-scattered electron microscopy and Raman spectroscopy. These analyses results demonstrate that the microbial fossils were organic remains (Kerogen) permineralized by