Eastern Peninsula Research Articles

Relationship of incidence of radix entomolaris and C-shaped canal in mandibular molars using CBCT: A multi-centre study.

This study aimed to evaluate the relationship of incidence between radix entomolaris (RE) in permanent mandibular first molars (FM) with C-shaped canal (CSC) in permanent mandibular second molars (SM). A total of 1015 cone-beam computed tomography (CBCT) images of permanent mandibular molars from Malaysian patients were collected retrospectively and analysed by researchers from seven dental schools in Malaysia trained in CBCT technology. The presence and absence of RE and CSC were scored as 'yes' or 'no'. The prevalence of FM with RE was 21.2% and SM with CSC was 37.9%. The co-occurrence of RE and CSC in the same quadrant was 6.5% (OR = 1.497, p = 0.014). Female, Chinese and samples from Eastern Peninsular Malaysia were associated with CSC in SM (p < 0.05). The increased appearance of CSC in SM when RE is present in FM makes it imperative for clinicians to be vigilant during examination and diagnosis to prevent potential endodontic mishaps.

The Kerguelen mantle plume activity in Sylhet Trap mafic rocks of Southern Shillong Plateau,NEIndia: Implications for its role in magmatism of eastern India

Mantle plumes related to Large Igneous Provinces have been linked to continental break‐up and validated by the outpouring of mafic‐ultramafic magmas that range from continental flood basalt magmatism to submarine plateau volcanism. This study presents a new set of geochemical and mineralogical data on mafic magmatic rocks from the Sylhet Trap of the Shillong Plateau, northeast India. The investigated mafic rocks (basalt and dolerite) are predominantly sub‐alkaline‐tholeiitic, composed of bytownite+labradorite and diopside+augite, with ophitic to sub‐ophitic and glomeroporphyritic textures, the dark interstitial region of much finer grains consisting of opaque minerals and devitrified glass. The mafic rocks of Sylhet Trap show light rare earth elements enrichment with (La/Yb)Nratio (1.92–2.86) and (La/Sm)Nratio (1.11–1.40), an almost flat pattern of heavy rare earth elements along with mild europium anomalies (Eu/Eu*= 0.94–1.11). Trace element characteristics suggest their affinity towards enriched mid‐oceanic ridge basalt and generated from low degree of partial melting of spinel source with minor involvement of crustal contamination. The similarity in geochemical characteristics of the investigated mafic rocks with the magmatism of Rajmahal Traps, eastern Peninsular India, Abor Volcanics, eastern Himalaya, along with Bunbury Basalt of western Australia and Cona Mafic exposed in southeastern Tibet, suggests their genetic linkage with mantle plume activities. Thus, we argue that the magmatic event of the Sylhet Trap is related to the Kerguelen mantle plume activity that played a significant role in the fragmentation of eastern Gondwana during the Lower Cretaceous period, giving rise to Greater India, Antarctica and northwest Australia.

Challenges in simulating the wind over a coastal complex-shaped site: Madeira Island

The wind behaviour on Madeira Island is shaped by the intricate coastline and mountainous terrain, features that are not easily represented in numerical models. Thus, this study addressed some challenges and possible solutions in setting up a meso-to-microscale model chain, with the WRF (1-km mesh) and VENTOS®/M (50-m mesh in the high-resolution area) models, in Madeira’s coastal and complex terrain. Wind measurements from four meteorological towers (located in the eastern peninsula–T0978/E–and on the SE–T0521/SE, S–T0522/S, and N–T0960/N–coasts) served as references to assess the simulations. First, due to WRF’s landmask position, land areas were misclassified as sea (and vice versa). This issue was addressed by altering the domain position to better allocate the landmask on the east peninsula, resulting in improved near-surface wind simulations at T0978/E (reducing RMSE and bias by 19% and 67%). Secondly, WRF’s default interpolation of the SST variable did not account for missing and masked data. As such, a different SST interpolation method was employed, leading to improved near-surface wind simulations at T0960/N (reducing RMSE and bias by 11% and 84%) and T0522/S (10% and 16% reduction) masts, but higher errors at T0978/E (7% and 45% increase). The negative influence arose from an incorrect speedup with the new interpolation method. Thirdly, the impact of SST_SKIN, which influences the temperature distribution at the skin level, was evaluated in WRF. Activating SST_SKIN led to a slight improvement in the near-surface wind simulation only at T0521/SE (2% and 6% RMSE and bias reduction), probably due to the dominant smaller-scale nature of the atmospheric circulation in the area, which contrasts with the circulation at the other towers, dominated by the trade winds (N and E masts) and the Island’s wake (S mast). When using the WRF outputs as boundary conditions, these effects on the microscale runs were less pronounced than on the mesoscale results. Nonetheless, the RMSE and bias of the near-surface wind simulation in VENTOS®/M were reduced by 6% and 9% at T0978/E.

Towards A Smart City Concept - Machine Learning Smarts for the Estimation of Future Temperature Rise in Tabuk City

In the Middle Eastern peninsula especially in Saudi Arabia, there is a varsity temperature variation among the individual regions. As far as the city of Tabuk is concerned, no study has been conducted, regarding climate change (the temperature rise) in the Tabuk region and its implications on society and for the flagship “Future Smart Cities” concept. In this paper, machine learning algorithms are used to predict the future temperature values in the Tabuk region. The machine learning algorithms were trained on the data collected from the real-time weather radar stations of the region. Different features from the dataset are used for machine learning models to predict the future temperature. These unique features, for example, humidity and pressure, impact the accurate predictability of the temperature. Temperature prediction is modelled as a regression problem due to the nature of the data, therefore, different machine learning regression models were developed, i.e. Artificial Neural Network ANN-based techniques (Multi-layer Perceptron (MLP)), Decision Trees (DT), K-Nearest Neighbours (KNN), and Support Vector Regression (SVR). Encouragingly, the preliminary model evaluations utilizing Mean Absolute Error (MAE) yielded a high accuracy of 90% on the testing dataset. The findings are envisaged to inform decision-makers in the Climate and Weather Ministry of Tabuk City, potentially contributing to the advancement of the city's "Future Smart Cities" concept.

Microbial biogeography of the eastern Yucatán carbonate aquifer.

The extensive Yucatán carbonate aquifer, located primarily in southeastern Mexico, is pockmarked by numerous sinkholes (cenotes) that lead to a complex web of underwater caves. The aquifer hosts a diverse yet understudied microbiome throughout its highly stratified water column, which is marked by a meteoric lens floating on intruding seawater owing to the coastal proximity and high permeability of the Yucatán carbonate platform. Here, we present a biogeographic survey of bacterial and archaeal communities from the eastern Yucatán aquifer. We apply a novel network analysis software that models ecological niche space from microbial taxonomic abundance data. Our analysis reveals that the aquifer community is composed of several distinct niches that follow broader regional and hydrological patterns. This work lays the groundwork for future investigations to characterize the biogeochemical potential of the entire aquifer with other systems biology approaches.

Coseismic and Tectonic Time-Scale Deformations of an Island Arc Based on Studies of East Coast of Kamchatka Peninsula (Far East, Russia)

Geologic structure of the late Holocene accumulative marine terrace on the coast of Kamchatka Bay (Kamchatka Peninsula) has been studied. The ages and relative hypsometric position of beach ridges composing the terrace allowed us to identify two types of vertical movements of the coast: periodic fast (coseismic) and slow time-scale uplift or subsidence. Large-amplitude vertical coseismic movements (up to 1‒2 meters) occur on average once in about 1200‒1300 years, and slow movements occur at an average rate from a fraction of a millimeter to about 2 mm per year. Coseismic motions represent relaxation of elastic deformations accumulated during the interseismic interval of the seismic cycle, neither exceed them nor accumulate. Slow motions set the general trend of vertical deformations of the coast. It is assumed that the subsiding central parts of the eastern bays of Kamchatka Peninsula (Avachinsky, Kronotsky and Kamchatsky) and depressions between the eastern peninsulas (Kronotsky, Shipunsky) and the main massif of Kamchatka form an arc-parallel extension zone, which is nearest to the deep-water trench, and that extension is caused by the migration of the subducted part of the Pacific plate toward the Pacific Ocean. Under the eastern Shipunsky and Kronotsky peninsulas, the arc-normal extension of the earth’s crust of the Kamchatka segment of the Kuril-Kamchatka island arc is replaced by a zone of transverse compression.

Analysis of the distribution pattern of the ectomycorrhizal fungus Cenococcum geophilum under climate change using the optimized MaxEnt model.

Cenococcum geophilum (C. geophilum) is a widely distributed ectomycorrhizal fungus that plays a crucial role in forest ecosystems worldwide. However, the specific ecological factors influencing its global distribution and how climate change will affect its range are still relatively unknown. In this study, we used the MaxEnt model optimized with the kuenm package to simulate changes in the distribution pattern of C. geophilum from the Last Glacial Maximum to the future based on 164 global distribution records and 17 environmental variables and investigated the key environmental factors influencing its distribution. We employed the optimal parameter combination of RM = 4 and FC = QPH, resulting in a highly accurate predictive model. Our study clearly shows that the mean temperature of the coldest quarter and annual precipitation are the key environmental factors influencing the suitable habitats of C. geophilum. Currently, appropriate habitats of C. geophilum are mainly distributed in eastern Asia, west-central Europe, the western seaboard and eastern regions of North America, and southeastern Australia, covering a total area of approximately 36,578,300 km2 globally. During the Last Glacial Maximum and the mid-Holocene, C. geophilum had a much smaller distribution area, being mainly concentrated in the Qinling-Huaihe Line region of China and eastern Peninsular Malaysia. As global warming continues, the future suitable habitat for C. geophilum is projected to shift northward, leading to an expected expansion of the suitable area from 9.21% to 21.02%. This study provides a theoretical foundation for global conservation efforts and biogeographic understanding of C. geophilum, offering new insights into its distribution patterns and evolutionary trends.

Multiple stages of continental rifting in Eastern Peninsular Malaysia: new insights from Jurassic–Cretaceous granitoids

Mesozoic granitoids in Peninsular Malaysia provide crucial information on the temporal–spatial relationship between the Tethyan and Palaeo-Pacific domains. This paper presents new ages and geochemical data for newly identified Jurassic–Cretaceous granites and meta-granites from East Malaya. These granitoids can be divided into three groups. Group 1 consists of high-K calc-alkaline granites and granodiorites (171–162 Ma) with variable ε Nd ( t ) values of −7.4–+0.5, zircon ε Hf ( t ) values of −7.4–+8.6, and high initial ratios for 206 Pb/ 204 Pb (20.04–20.65), 207 Pb/ 204 Pb (15.73–15.79) and 208 Pb/ 204 Pb (39.80–40.20). The melting of metasedimentary rocks with a juvenile mafic component formed Group 1 samples. Group 2 granite porphyries ( c. 131 Ma) with A-type affinities and Group 3 granitic gneisses ( c. 130 Ma) with I-type affinities share similar ε Nd ( t ) values (−7.2 to −5.5), zircon ε Hf ( t ) values (−10.1–+6.5), and initial ratios for 206 Pb/ 204 Pb (18.81–19.02), 207 Pb/ 204 Pb (15.71–15.77) and 208 Pb/ 204 Pb (38.95–39.59). Although Group 2 and 3 samples were derived from an ‘ancient’ meta-mafic source region, Group 2 shows evidence for the involvement of a juvenile mafic component. All these granitoids are akin to the Permian–Triassic igneous rocks in East Malaya. The Jurassic–Cretaceous igneous rocks in Eastern Peninsular Malaysia were formed during multiple stages of continental rifting in response to Palaeo-Pacific slab rollback pulses rather than by Tethyan evolutionary processes. Supplementary material : Data for the Middle Jurassic–Early Cretaceous granitoids of East Malaya are available at https://doi.org/10.6084/m9.figshare.c.6689085 Thematic collection: This article is part of the Mesozoic and Cenozoic tectonics, landscape and climate change collection available at: https://www.lyellcollection.org/topic/collections/mesozoic-and-cenozoic-tectonics-landscape-and-climate-change

Mitochondrial cytochrome c oxidase subunit I gene analysis of the yellowfin snapper, Lutjanus xanthopinnis in the Indo-Pacific region and a note on Lutjanus lutjanus population structure

The yellowfin snapper, Lutjanus xanthopinnis, was recorded as a newly described species in the Indo-Pacific region in 2015. However, the knowledge of its biology, biogeography and ecology is scarcely understood, and, hence, its current conservation status is categorized as Data Deficient. The mitochondrial cytochrome c oxidase subunit I (COI) gene was examined to confirm species identification. We also examined the COI gene haplotypes of L. xanthopinnis in Brunei Darussalam and Malaysia together with other waters, i.e., Bangladesh, Indonesia, Japan, Singapore, Sri Lanka and Taiwan. Our molecular analyses found that Brunei Darussalam and eastern Peninsular Malaysia samples were genetically similar. However, the former showed higher genetic diversity than the latter. The samples from these two sites also showed signatures of population expansion. Furthermore, identical haplotypes could be found in different locations, suggesting the absence of spatial genetic structure. On the other hand, Lutjanus lutjanus showed a population structure associated with geographical locations, i.e., western Pacific Ocean, Indian Ocean and Maluku in Indonesia.

Antarctic iceberg melt rate variability and sensitivity to ocean thermal forcing

AbstractChanges in iceberg calving fluxes and oceanographic conditions around Antarctica have likely influenced the spatial and temporal distribution of iceberg fresh water fluxes to the surrounding ocean basins. However, Antarctic iceberg melt rate estimates have been limited to very large icebergs in the open ocean. Here we use a remote-sensing approach to estimate iceberg melt rates from 2011 to 2022 for 15 study sites around Antarctica. Melt rates generally increase with iceberg draft and follow large-scale variations in ocean temperature: maximum melt rates for the western peninsula, western ice sheet, eastern ice sheet and eastern peninsula are ~50, ~40, ~5 and ~5 m a−1, respectively. Iceberg melt sensitivity to thermal forcing varies widely, with a best-estimate increase in melting of ~24 m a−1°C−1and range from near-zero to ~100 m a−1°C−1. Variations in water shear likely contribute to the apparent spread in thermal forcing sensitivity across sites. Although the sensitivity of iceberg melt rates to water shear prevents the use of melt rates as a proxy to infer coastal water mass temperature variability, additional coastal iceberg melt observations will likely improve models of Southern Ocean fresh water fluxes and have potential for subglacial discharge plume mapping.

Space-based observation of early summer wildfire event and its environmental proxies during 2021 in Eastern Peninsular India

Space-based observation of early summer wildfire event and its environmental proxies during 2021 in Eastern Peninsular India

Prevalence and impact of work-related musculoskeletal disorders among food delivery riders in Eastern Peninsular Malaysia

Work-related Musculoskeletal Disorders (WMSDs) are currently a matter of concern in the occupational world, where it is the leading cause of disability among workers. Food delivery riders were among the neglected workers even though they were highly exposed to the WMSDs. Thus, this study aims to quantify the magnitude of WMSDs among the riders and the impact on their work. This was a cross-sectional study involving 191 food delivery riders in Eastern Peninsular Malaysia. The Standardized Nordic Musculoskeletal Questionnaire (M-SNMQ), which was self-administered and validated for Malay translation, was used to quantify the prevalence of WMSDS based on various specific body regions. WMSD prevalence over a 12-month period was 74.9%. Upper back pain (UBP) (55.6%) and lower back pain (LBP) (73.3%) were the two most common body regions to experience WMSD symptoms. The least-complained body regions were thighs and feet, with a prevalence of 2.6% and 3.1%, respectively. The affected body regions that caused the highest daily life disturbance were the shoulders and knees, while those with shoulders symptom were more likely to be absent from work. Finally, LBP was the highest body region with at least a moderate pain score. In general, the findings should be a matter of concern among health authorities and others to improve the quality of life among the riders. To lower the prevalence of WMSDs among this understudied group, additional interventional research should be built on the findings of this study.

The dynamics of a changing Lutz spruce (Picea×lutzii) hybrid zone on the Kenai Peninsula, Alaska

We investigated the genetic makeup of Lutz spruce, a natural hybrid between white and Sitka spruce on the Kenai Peninsula, Alaska. Microsatellites indicate 72% of individuals sampled had predominantly white spruce ancestry, whereas 14% had predominantly Sitka spruce ancestry; some individuals classified as white spruce had Sitka spruce plastid genotypes. As Picea mitochondria are maternally inherited and plastids are paternally inherited, it appears that white spruce was the ancestral seed parent of nearly all spruce on the western peninsula, whereas Sitka spruce alleles originated from pollen. Pollen records show that white spruce colonized the western peninsula ∼8500 YBP from glacial refugium, whereas Sitka spruce arrived on the eastern peninsula ∼4000 YBP after migrating up the Pacific coast. Our data suggest that Sitka spruce colonization west of the Kenai Mountains may have occurred not via seed dispersal but by long distance transport of wind-borne pollen and subsequent hybridization with established white spruce populations. Hybridization was an important mechanism that allowed Sitka spruce to expand the leading edge of its range in response to historical climate change. As the climate continues to warm, climate envelope modeling suggests Lutz spruce may ultimately displace white spruce on the western peninsula even as Sitka spruce is constrained to the eastern peninsula where it will continue to hybridize.

Late Paleozoic–Early Mesozoic granitic rocks in Eastern Peninsular Malaysia: New insights for the subduction and evolution of the Paleo-Tethys

• The granitoids in East Malaya were emplaced at 289–244 Ma. • The granitoids were formed in response to the Paleotethyan subduction . • The slab roll-back of the Eastern Paleotethyan initially occur at ∼ 270 Ma. • Subduction-related granitoids in East Malaya can extend to SW China and W Borneo. Well-preserved Late Paleozoic–Early Mesozoic igneous rocks in Peninsular Malaysia are important for investigating the Paleotethyan tectonic evolution. This study presents new zircon U-Pb dating, whole-rock geochemical, and Sr-Nd-Pb-Hf isotopic data for granitoids identified from the East Malaya. By utilizing all available data, the Permian–Middle Triassic granitoids in Eastern Peninsular Malaysia can be divided into three groups. Group A (289–270 Ma) I-type granites have higher ε Nd (t) values of − 6.6 to − 2.6 and zircon ε Hf (t) values of − 7.1 to + 4.9 than Group B S-type granites (285–272 Ma) with ε Nd (t) = − 10.1 and zircon ε Hf (t) = − 23.1 to + 1.5. Group C (254–244 Ma) with A-type characteristics, has ε Nd (t) and zircon ε Hf (t) values ranging from − 7.3 to − 3.8 and − 8.9 to + 2.2, respectively. The Pb isotopic values for three groups are similar with ( 206 Pb/ 204 Pb) i = 18.71–19.43, ( 207 Pb/ 204 Pb) i = 15.66–15.71 and ( 208 Pb/ 204 Pb) i = 38.27–39.43. Group A was derived from metaigneous rocks with a juvenile mafic component, while Group B was from metasedimentary rocks. Group C had a mixed source of “ancient” meta-mafic rocks with a juvenile mafic component. This study proposes that the Late Paleozoic–Early Mesozoic granitoids were formed in response to the subduction of the Paleotethyan Ocean, and that a tectonic transition from subduction to slab roll-back might occur at ∼ 270 Ma. Subduction-related granitoids in East Malaya can northernly extend to the Tachileik Batholith in eastern Myanmar and Jinghong in SW China, and southernly link with W Borneo.

Markovian and rescaled range analysis-based probe into the pattern of rainfall over Eastern Peninsular India

Markovian and rescaled range analysis-based probe into the pattern of rainfall over Eastern Peninsular India

Recent advances in date palm genomics: A comprehensive review.

As one of the oldest fruit trees of the Arabian peninsula, other Middle-Eastern countries, and also North Africa, the date palm (Phoenix dactylifera L.), is highly significant for the economy of the region. Listed as part of UNESCO’s Intangible Cultural Heritage of Humanity, the date palm is believed to be the first tree cultivated by human beings, and was probably first harvested for its fruit nearly 7,000 years ago. Initial research efforts in date palm genetics focused on understanding the genetic diversity of date palm germplasm collections and its phylogenetic history, both important prerequisites for plant improvement. Despite various efforts, the center of origin of the date palm is still unclear, although genomic studies suggest two probable domestication events: one in the Middle East and the other in North Africa, with two separate gene pools. The current review covers studies related to omics analyses that have sought to decipher the present genetic diversity of the date palm. With advances and cost reductions in sequencing technologies, rapid progress has been made in the past few years in date palm genomics research. Along with organellar genomes, several reference genomes of the date palm are now available. In addition, several genotypes have been re-sequenced, either to detect single nucleotide polymorphisms (SNPs), or to study domestication and identification of key genes/loci associated with important agronomic traits, such as sex, fruit color, and sugar composition. These genomics research progress has paved the way to perform fast-track and precise germplasm improvement processes in date palm. In this study, we review the advances made in the genetics and genomics of the date palm so as to strategize targeted crop improvement plans for marginal areas of the Middle Eastern peninsula, North Africa, and other parts of the world.

Assessment of Fine Particulate Matter for Port City of Eastern Peninsular India Using Gradient Boosting Machine Learning Model

An assessment and prediction of PM2.5 for a port city of eastern peninsular India is presented. Fifteen machine learning (ML) regression models were trained, tested and implemented to predict the PM2.5 concentration. The predicting ability of regression models was validated using air pollutants and meteorological parameters as input variables collected from sites located at Visakhapatnam, a port city on the eastern side of peninsular India, for the assessment period 2018–2019. Highly correlated air pollutants and meteorological parameters with PM2.5 concentration were evaluated and presented during the period under study. It was found that the CatBoost regression model outperformed all other employed regression models in predicting PM2.5 concentration with an R2 score (coefficient of determination) of 0.81, median absolute error (MedAE) of 6.95 µg/m3, mean absolute percentage error (MAPE) of 0.29, root mean square error (RMSE) of 11.42 µg/m3 and mean absolute error (MAE) of 9.07 µg/m3. High PM2.5 concentration prediction results in contrast to Indian standards were also presented. In depth seasonal assessments of PM2.5 concentration were presented, to show variance in PM2.5 concentration during dominant seasons.

Regional modulating behavior of Indian summer monsoon rainfall in context of spatio-temporal variation of drought and flood events

In this paper, daily modulating behaviors of Indian summer monsoon rainfall (ISMR) has been evaluated over eight important sub-zones of India viz Northwest India (NWI); Northcentral India (NCI); West Peninsular India (WPI); Eastern Peninsular India (EPI); Southern Peninsular India (SoPI); Central India (CI), Northeast India (NEI) and Western Ghat (WG) using latest SA-CORDEX simulated climate data during 1981–2015. The climate extreme indices, standardized precipitation index (SPI) and empirical orthogonal function (EOF) have been utilized to uncover substantial regional spatial patterns and temporal variability of monsoon precipitation over India and its sub regions to understand the regional modulation of these events based on duration, frequency and severity. The comprehensive assessment of ISMR modulated characteristics (intensity, spell, and frequency) were showing significant decreasing trend over NEI and NCI which can be leading factors for demarcating major hotspots for land degradation, effective management and adaptation towards water resources and hazards related to the flood/drought events. India has received flood events (1983, 1988, 1994, 2005, 2011, 2013) and drought event (1982, 1987, 2002, 2004 and 2009) during 1981–2015, which have been verified with SA-CORDEX RCMs (RegCM4.7, COSMO & REMO2015) using SPI. The first mode of EOF(IMD), explained 17% of the total SPI variability on the interannual scale, shows anomalous large positive values concentrated over the western peninsular region and extending towards central India as well as the NWI region of India. On the other hand, high anomalous negative values dominated over the NEI and eastern parts of the Indo-Gangetic Plain. Therefore, this study underscores the importance to uncover the prevalent dynamics and climate change variability on changing trend variability of the precipitation indices, drought and flood characteristics. As moderate to severe drought variability portrays a diversity over regional scale viz northwest India, north central India, eastern ghat of the southern peninsular region and northeast India while the occurrence of moderate to severe flood are dominated towards Himalaya region (26°N-35°N; 70°E-80°E), western peninsular region and western ghat.

Taxonomic Composition of the Oligodon arnensis (Shaw 1802) Species Complex (Squamata: Colubridae) with the Description of a New Species from India

We review the taxonomic status of Oligodon arnensis (Shaw 1802) after examining all the name-bearing types of its synonyms, and evaluating morphological and biogeographic evidence. Oligodon arnensis sensu lato is widely distributed throughout Peninsular India, Sri Lanka, Pakistan, Nepal, Bhutan, and Bangladesh. We demonstrate that southern, eastern, and western populations in India represent three distinct species. Oligodon arnensis sensu stricto described from Arnee (now Arani), Tamil Nadu, southern India, is distributed in southern India up to 1500 m above sea level. Oligodon albiventer Günther 1864 and Simotes russellii var. ceylonensis Müller 1887 described from Sri Lanka closely match O. arnensis sensu stricto, and hence we treat them as junior synonyms. We resurrect Coluber russelius Daudin 1803 from the synonymy of O. arnensis, designate a lectotype, and restrict its type locality to Vizagapatam (now Visakhapatnam), Andhra Pradesh, eastern Peninsular India. Based on morphological differences we describe a new species from Kurduvadi, in the Deccan plateau of western India representing the western Indian population of O. arnensis sensu lato. We provide redescriptions for O. arnensis sensu stricto and O. russelius comb. nov. based on museum specimens, as both were named based on illustrations (iconotypes). Based on our update of the currently confirmed localities for O. arnensis, O. russelius comb. nov. and the new species, we discuss their biogeography and conservation status.

Compositional Variation in the Crust of Peninsular Ranges and Surrounding Regions, Southern California, Revealed by Full‐Wave Seismic and Gravity Joint Inversion

AbstractDetailed three‐dimensional models of crustal compositional variations are essential for better understanding crustal evolution and dynamics. High‐resolution wave speed and density models of the crust provide one of the most important constraints on crustal compositional variations, particularly at depths beyond direct rock sampling. Here we present a three‐dimensional density and wave speed model of Southern California obtained by jointly inverting gravity anomalies and seismic component‐differential phase delays with full‐wave sensitivity kernels, which provide a link between wave speed and density. Thus, unlike previous joint seismic and gravity inversions, the new model does not depend on an empirical relationship between wave speed and density. The resulting density and compressional‐to‐shear wave‐speed ratio (Vp/Vs) reveal detailed features of compositional variations in the upper and middle crust in the study area, such as the three‐dimensional geometry of the boundary between the western and eastern portions of the Peninsular Ranges batholith, the gabbro‐ and metavolcanics‐rich locations within the Western Peninsular Ranges batholith, the variation of sedimentary basin thickness beneath the Coachella Valley, and a likely intermediate‐to‐mafic batholith beneath the Coachella Valley and the Eastern Peninsular Ranges. The jointly inverted density and Vp/Vs values also suggest a lithological control on seismic activities off the major fault zones.