Recurrent Primary Intrasellar Paraganglioma

We describe a case of an 81-year-old male presenting with bitemporal visual field defects and blurry vision in the right eye. The patient was found to have a recurrent primary paraganglioma in the sellar and suprasellar region requiring a repeat transsphenoidal endoscopic resection. Immunohistochemical examination confirmed paraganglioma with the classic zellballen appearance which stained positive for chromogranin, synaptophysin, and S-100 in the periphery. Paragangliomas (PGLs) in the sella turcica are a rare entity; only 19 cases have ever been reported in the literature. PGLs in the sellar region are often misdiagnosed or diagnosed in a delayed fashion. Earlier diagnosis of this locally aggressive tumor and meticulous debulking can prevent morbidity secondary to the tumor's compressive effects. This report highlights the effectiveness of surgical interventions in treatment of paragangliomas. More research is still needed to determine the need for adjuvant therapies such as radiation

New age constraints for the Salamanca Formation and lower Río Chico Group in the western San Jorge Basin, Patagonia, Argentina: Implications for Cretaceous-Paleogene extinction recovery and land mammal age correlations

The Salamanca Formation of the San Jorge Basin (Patagonia, Argentina) preserves critical records of Southern Hemisphere Paleocene biotas, but its age remains poorly resolved, with estimates ranging from Late Cretaceous to middle Paleocene. We report a multi-disciplinary geochronologic study of the Salamanca Formation and overlying Rio Chico Group in the western part of the basin. New constraints include (1) an 40Ar/39Ar age determination of 67.31 ± 0.55 Ma from a basalt flow underlying the Salamanca Formation, (2) micropaleontological results indicating an early Danian age for the base of the Salamanca Formation, (3) laser ablation HR-MC-ICP-MS (high resolution-multi collector-inductively coupled plasma-mass spectrometry) U-Pb ages and a high-resolution TIMS (thermal ionization mass spectrometry) age of 61.984 ± 0.041(0.074)[0.100] Ma for zircons from volcanic ash beds in the Penas Coloradas Formation (Rio Chico Group), and (4) paleomagnetic results indicating that the Salamanca Formation in this area is entirely of normal polarity, with reversals occurring in the Rio Chico Group. Placing these new age constraints in the context of a sequence stratigraphic model for the basin, we correlate the Salamanca Formation in the study area to Chrons C29n and C28n, with the Banco Negro Inferior (BNI), a mature widespread fossiliferous paleosol unit at the top of the Salamanca Formation, corresponding to the top of Chron C28n. The diverse paleobotanical assemblages from this area are here assigned to C28n (64.67–63.49 Ma), ∼2–3 million years older than previously thought, adding to growing evidence for rapid Southern Hemisphere floral recovery after the Cretaceous-Paleogene extinction. Important Peligran and “Carodnia” zone vertebrate fossil assemblages from coastal BNI and Penas Coloradas exposures are likely older than previously thought and correlate to the early Torrejonian and early Tiffanian North American Land Mammal Ages, respectively.Centro de Investigaciones Geográfica

Reef Foraminifera as Bioindicators of Coral Reef Health: Low Isles Reef, Northern Great Barrier Reef, Australia

Declining water quality associated with changes in land use over the past century is considered a significant environmental threat to the health of coral platforms of the Great Barrier Reef, Australia, in particular for those situated in nearshore areas of the wet tropics. Of these reefs, perhaps the most well known is Low Isles Reef, which has been studied since 1928. Decline in scleractinian coral cover and increased abundances of soft-bodied corals and macroalgae since the 1950’s have led researchers to speculate that the reef is being affected by increased nutrient and sediment fluxes from nearby rivers. The Foraminifera in Assessment and Monitoring (FORAM) Index (Hallock and others, 2003) is a numerical indicator of the suitability of water quality to support reef growth based on foraminiferal assemblages. To assess whether nutrification is an issue near Low Isles Reef, FORAM Index (FI) values were calculated from a suite of 50 samples collected from the reef top. Results were compared to FI values from Heron Reef, a mid-shelf platform in the southern Great Barrier Reef Province known for its lush scleractinian coral population. FI values from both reefs indicate that, overall, conditions favor coral growth. A Student’s t test indicates the FI values between the two reefs are similar. Principal components analysis shows that the FI values are not being constrained by water depth or depositional environment. Lower FI values, which indicate conditions unsuitable to marginal for coral growth, are restricted to particular locations on Low Isles Reef and can be explained in the context of local processes associated with the long-term geomorphological evolution of the reef. Results (1) do not support the notion that agricultural activities in nearby coastal catchments have adversely affected coral populations on Low Isles Reef and (2) demonstrate the applicability of the FI for regions outside of the western Atlantic and Caribbean, for which the index was originally created

Data from: The Probable Datum Method (PDM): a technique for estimating the age of origination or extinction of nannoplankton

Accurate interpretation of origination and extinction of fossil species is crucial to answering a variety of questions in paleontology. Fossil datums, the observed age of first or last occurrences, are subject to sampling error as a result of preservation and low abundances near range endpoints. This sampling error can cause local range offset, an age difference between the observed first or last occurrence of a species and its true origination or extinction. Here we develop and test a new technique, the Probable Datum Method (PDM) that can be used to assess the extent of local range offset for nannofossil species. The PDM estimates the original abundance of a taxon and its probable true age of first or last occurrence. The PDM uses a model in which original abundance is related to count abundance through preservation and the counting process. This model is empirically parameterized, including an experimental determination of false positive and error rates of a nannofossil count. The model is simulated then inverted to estimate likely original abundance and true datum age from count abundance data. We first test the PDM in a positive control experiment with known parameter values. This experiment shows the PDM is robust and returns known values accurately. Next we apply the method to the origination of nannoplankton after the Cretaceous/Paleogene boundary to test whether first occurrences were synchronous between widely-spaced locations. The PDM results suggest that observed diachrony of K/Pg originations cannot be explained by the effects of range offset, rather in some cases they indicate truly diachronus first occurrences between localities. Although the technique was developed to analyze nannoplankton ranges, the statistical nature of the PDM, its experimentally derived parameters and parsimonious nature should make it applicable to many micropaleontological studies that interpret patterns of origination and extinction

Data from: The role of regional survivor incumbency in the evolutionary recovery of calcareous nannoplankton from the Cretaceous/Paleogene (K/Pg) mass extinction

The earliest Paleocene record of calcareous nannoplankton presents a unique opportunity to understand the evolutionary recovery of life from mass extinction. Nannoplankton were devastated at the Cretaceous/Paleogene boundary and their subsequent recovery can be studied in great detail because of their abundance in sediments, continuous stratigraphic occurrence, and near global distribution. Here we determine when and where new species of nannoplankton originated and how they dispersed following the Cretaceous/Paleogene mass extinction. Initially, we focus our efforts on North Pacific and South Atlantic deep sea sites with orbital age control to compare the precise timing and dynamics of the recovery between the locations. We then broaden our investigation to six sites from different basins and a variety of environments to study global patterns of the initial recovery. Our results show that many taxa in key Paleogene lineages originated in the North Pacific Ocean and that assemblages comprised primarily of new Paleogene taxa were not observed at other sites for several hundred thousand years. Survivors that were adapted to eutrophic post extinction conditions rapidly expanded in Southern Hemisphere sites where they dominated assemblages for most of the initial recovery. We therefore hypothesize that groups of survivors formed regionally incumbent assemblages in the Southern Hemisphere that limited diversification and dispersal of new Paleogene taxa. The end of survivor dominance correlates to the recovery of the biologic pump and subsequent decrease in surface ocean nutrient concentration 300–400 Kyr after the boundary. Only after survivors were removed did new Paleogene nannoplankton assemblages become abundant globally. Our results indicate that competition from regionally incumbent survivors was as an important control on the K/Pg recovery of nannoplankton

Schueth et al. K/Pg nannofossil recovery Supplement

Supplemental Materials for the manuscript "The role of regional survivor incumbency in the evolutionary recovery of calcareous nannoplankton from the Cretaceous/Paleogene (K/Pg) mass extinction." Includes supplemental figures, supporting information for main text and age models used in analysis

PDM code files and readme

Included in this package are all code required to run the PDM and a readme file to explain how to implement the PDM for use

Schueth et al Supplementary Materials

Supplementary appendices for the Probable Datum Method manuscript. Included are: positive control appendix, sensitivity analysis, comparison with other methods, etc

Schueth et al. K/Pg nannofossil recovery Supplement - Cluster Dendrogram

Additional supplement for the article "The role of regional survivor incumbency in the evolutionary recovery of calcareous nannoplankton from the Cretaceous/Paleogene (K/Pg) mass extinction" - contains the cluster analysis results with dendrograms and taxa abundances plotted along with dendrograms