Biology subjects

Noto, C.

Publications and source records attributed to Noto, C..

3 recordsLinked to original sources

bioRxiv2023

A Glimpse Into the Cenomanian: Palynology of the Arlington Archosaur Site, Late Cretaceous Western Interior Seaway, Texas, USA

The Arlington Archosaur Site (AAS) between Dallas and Fort Worth, Texas, is known as a rich fossiliferous section. The age of these rocks is generally considered to be mid-Cenomanian, but conflicting evidence suggests the age may be as young as the late Cenomanian-early Turonian. To address the issue, a palynological study was designed and conducted based on the close sampling of the lithofacies. Palynological samples were processed according to the standard acid preparation. The study was quantitative and focused on associations to determine the paleoenvironment, paleoclimate, biostratigraphy, and age of exposure. The rich palynological assemblages comprise spores from seedless plants, gymnosperms, angiosperms, fungi, algae, and dinoflagellate cysts. Bryophytes were abundant mainly in Facies A and B, with Zlivisporis cenomanianus taking over the bryophytes habitat in Facies D. Lycophytes abundant in the alluvial and coastal plains are considered to have been transported. Conifers were the predominant group of gymnosperms, also mainly transported into the section. Freshwater algal remains include Schizophacus laevigatus/Ovoidites parvus, Schizosporis reticulatus, Botryococcus sp., and Pediastrum sp. Acanthomorph acritarchs present in low abundance and diversity appear following shallow marine dinoflagellates spikes and before freshwater colonial algal spikes. The vegetation signal at Notos Facies A and B indicates tropical to subtropical shallow marine to coastal plains, while Notos Facies D indicates tidally influenced areas. Also, picks of the diversity and abundance of dinoflagellate cysts are interpreted as an increased marine influence and proposed as possible flooding surfaces. The results support the alternation of marine incursions within deltaic and floodplain sequences, related to regional climate oscillation that affected the vegetation on the upland drainage area. Key palynological markers point to an early Late Cenomanian age, and the presence of the Cyclonephelium compactum-C. membraniphorum (Ccm morphological plexus) signals that the incursion of boreal waters during the Plenus Cold Event of the Ocean Anoxic Event 2 may have reached as far south as the AAS area. This coincides with vegetation trends that suggest a cooler and less humid climate at the start of Facies A, where Ccm is more abundant.

paleontology↗

bioRxiv2019

Quantifying shape, integration, and ecology in avian pedal claws: comparing geometric morphometric and traditional metric approaches

Terrestrial tetrapods use their claws to interact with their environments in a plethora of ways. Birds in particular have developed a diversity of claw shapes since they are not bound to terrestrial locomotion and have heterogeneous body masses ranging several orders of magnitude. Numerous previous studies have hypothesized a connection between pedal claw shape and ecological mode in birds, but have generated conflicting results, spanning from clear ecological groupings based on claw shape to a complete overlap of ecological modes. These studies have relied on traditional morphometric arc measurements of keratinous sheaths and have variably accounted for likely confounding factors such as body mass and phylogenetic relatedness. To better address the hypothesized relationship between ecology and claw shape in birds, 580 radiographs were collected allowing visualization of the bony core and keratinous sheath shape spanning 21 avian orders. A new method was used to quantify claw shape using geometric morphometrics and was compared to results using traditional arc measurements. Neither traditional nor geometric morphometrics are capable of significantly separating bird claws into coarse ecological categories after integrating body size and phylogenetic relatedness. Further, the bony claw core and keratinous sheath are significantly integrated with one another, suggesting that they function as a single unit. Therefore, it is likely possible to compare fossil bony cores with extant keratinous sheaths after applying corrections. Finally, traditional metrics and geometric morphometric shape are significantly, yet loosely correlated, and geometric morphometric data better distinguish ecological groups in morphospace than is possible with traditional metrics. Based on these results, future workers are encouraged to use geometric morphometric approaches to study claw geometry and account for confounding factors such as body size, phylogeny, and individual variation prior to predicting ecology in fossil taxa.

evolutionary biology↗

bioRxiv2017

Applying polygenic risk scoring for psychiatric disorders within a family context

We aim to investigate the application of polygenic risk scoring within a family context. Polygenic risk profiles could aid in unraveling the role that common variation confers on disease risk within a pedigree that would have traditionally been viewed through the prism of monogenic inheritance only. We illustrate our discussion by analyzing polygenic risk scores for schizophrenia, major depressive disorder and bipolar disorder in a large pedigree (n~260) in which 30% of family members suffer from major depressive disorder or bipolar disorder. We apply polygenic risk scores to study patterns of assortative mating and anticipation, whereby it appears increased polygenic risk for psychiatric disorders is contributed by affected individuals who married into the family, resulting in an increasing genetic risk over generations in the family. This may explain the observation of anticipation in mood disorders, whereby onset is earlier and the severity of a disease increases over the generations of a family. Joint analyses of both rare and common variation may be the most powerful way to understand the familial genetics of mood and psychiatric disorders.

genetics↗