Looking our limitations in the eye: A call for more thorough and honest reporting of study limitations

The replication crisis and subsequent credibility revolution in psychology have highlighted many suboptimal research practices such as p‐hacking, overgeneralizing, and a lack of transparency. These practices may have been employed reflexively but upon reflection, they are hard to defend. We suggest that current practices for reporting and discussing study limitations are another example of an area where there is much room for improvement. In this article, we call for more rigorous reporting of study limitations in social and personality psychology articles, and we offer advice for how to do this. We recommend that authors consider what the best argument is against their conclusions (which we call the “steel‐person principle”). We consider limitations as threats to construct, internal, external, and statistical conclusion validity (Shadish et al., 2002), and offer some examples for better practice reporting of common study limitations. Our advice has its own limitations — both our representation of current practices and our recommendations are largely based on our own metaresearch and opinions. Nevertheless, we hope that we can prompt researchers to write more deeply and clearly about the limitations of their research, and to hold each other to higher standards when reviewing each other's work

Multiple sea-ice states and abrupt MOC transitions in a general circulation ocean model

Sea ice has been suggested, based on simple models, to play an important role in past glacial–interglacial oscillations via the so-called “sea-ice switch” mechanism. An important requirement for this mechanism is that multiple sea-ice extents exist under the same land ice configuration. This hypothesis of multiple sea-ice extents is tested with a state-of-the-art ocean general circulation model coupled to an atmospheric energy–moisture-balance model. The model includes a dynamic-thermodynamic sea-ice module, has a realistic ocean configuration and bathymetry, and is forced by annual mean forcing. Several runs with two different land ice distributions represent present-day and cold-climate conditions. In each case the ocean model is initiated with both ice-free and fully ice-covered states. We find that the present-day runs converge approximately to the same sea-ice state for the northern hemisphere while for the southern hemisphere a difference in sea-ice extent of about three degrees in latitude between the different runs is observed. The cold climate runs lead to meridional sea-ice extents that are different by up to four degrees in latitude in both hemispheres. While approaching the final states, the model exhibits abrupt transitions from extended sea-ice states and weak meridional overturning circulation, to less extended sea ice and stronger meridional overturning circulation, and vice versa. These transitions are linked to temperature changes in the North Atlantic high-latitude deep water. Such abrupt changes may be associated with Dansgaard–Oeschger events, as proposed by previous studies. Although multiple sea ice states have been observed, the difference between these states is not large enough to provide a strong support for the sea-ice-switch mechanism

Australian Cainozoic Bryozoa, 1: Nudicella gen. nov (Onychocellidae, Cheilostomata): taxonomy, palaeoenvironments and biogeography

The new bryozoan genus Nudicella (Onychocellidae, Cheilostomata) is proposed to accommodate the common and widespread Australian Cainozoic cheilostome bryozoan Eschara clarkei Tenison Woods, which is redescribed and subdivided into four species: N. clarkei (Tenison Woods), N. cribriforma sp. nov., N. latiramosa sp. nov. and N. tenuis sp. nov. Cellaria gigantea Maplestone is also reassigned to Nudicella. Colonies of this genus display a wide variety of growth forms, including cribrate fenestrate, flat robust branching, foliose, delicate branching and encrusting; their occurrences correlate with changes in sedimentary facies and palaeoenvironments. The distinctive cribrate style of fenestrate growth form has evolved convergently in unrelated bryozoan groups at various geological intervals. It is found in a wide variety of sedimentary facies, as in other coexisting opportunistic genera such as Celleporaria, indicating a wide ecological tolerance. The oldest recorded occurrence of Nudicella is in the Paleocene of north western Australia. From there it appears to spread south in the Eocene and then east towards the Otway Basin in southeastern Australia, where it occurs in the Oligocene and Miocene; no post-Miocene representatives of this genus are yet known. © 2004 Association of Australasian Palaeontologists

Origin of the Late Neogene Roe Plains and their calcarenite veneer: implications for sedimentology and tectonics in the Great Australian Bight

The Roe Calcarenite, a 2-3 m-thick, soft, quartzose molluscan sand of grainstone to rudstone texture, is a critical unit for deciphering the geodynamic and sea-level history of the southern Australian continental margin. Biostratigraphic and Sr-isotope analysis of molluscs and brachiopods confirms that the unit is Late Pliocene. Amino acid racemisation analyses indicate a minimum age of Early Pleistocene. The general depositional environment was a shallow illuminated shoreface to the inner shelf with the seafloor probably covered by seagrass, much like the modern seafloor offshore the Roe Plains today, but perhaps somewhat warmer. The calcarenite lies on an interpreted marine erosion surface cut into Upper Oligocene to Middle Miocene Eucla Group cool-water carbonates. Such planation, which affected all of the inner shelf, took place throughout the Early Pliocene due to the combination of uplift via basin inversion and eustatic highstand. The process, which led to ∼85 km of cliff retreat in ∼3 million years, is interpreted to be a variant on the shaved shelf process operating on the shelf today. The Roe Calcarenite is envisaged as the last of many calcarenites deposited during small-scale highstands that were eroded during subsequent transgressions. It is preserved because the Roe Plains were uplifted immediately after deposition, part of a widespread Plio-Pleistocene boundary tectonic event. It has been continuously exposed since uplift and subject to arid-zone pedogenic diagenesis. This succession is a relatively quiescent example of uplift, erosion and deposition related to basin inversion. It was much less intense than coeval events further east in the St Vincent, Otway and Gippsland Basins. Together, these Late Neogene tectonic-sedimentary packages illustrate the spectrum of stratigraphic successions that might be expected from basin inversion along an otherwise passive continental margin. © Geological Society of Australia.James, N. P. Bone, Y. ; Carter, R. M. ; Murray-wallace, C. V