Terrestrial arthropods from the Late Pleistocene of Jamaica: systematics,palaeoecology and taphonomy

The Red Hills Road Cave, Jamaica, is the most important site for terrestrial arthropods in the post‐Miocene of the Greater Antilles. Its fauna includes millipedes, isopods, crabs and insects, in addition to land snails and vertebrates. Arthropods are preserved in three dimensions and delicate structures such as limbs can be recognized. This unusual preservation was favoured by acidic groundwater rich in dissolved calcium carbonate; periods of high rainfall during which the bottle‐shaped cave was filled with water; and any arthropod washed in would have drowned. The absence of spiders, centipedes and most insects is due to the absence of carbonate in their exoskeletons. Millipedes and isopods possess a potential for preservation by carbonate mineralization that does not occur in other groups; they secrete calcium carbonate in the exoskeleton which hardens the cuticle and is water permeable, bringing about mineral replacement of the original structures. Within the cave, fossil millipede taxa include Rhinocricus sp. or spp., Chondrotropis sp., Caraibodesmus verrucosus (Pocock) and Cyclodesmus sp. cf. C. porcellanus Pocock. The isopod fauna includes Pseudarmadillo sp., Venezillo boonae Van Name, and Philoscia spp. 1 and 2. Crab claws belong to Sesarma sp. cf. S. cookei Hartnoll. Millipedes and isopods are particularly complete, representing drowned individuals fossilized soon after death; land crabs occur as fingers and rare chelae, suggesting that they may be exuviae. Only the most robust parts of insects have been discovered, but are particularly rare, consisting of three taxa of fly puparia and one possible beetle elytra. Copyright © 2012 John Wiley & Sons, Ltd.     

Urban geology: modelling Coal Measures strata in the nineteenth and twenty‐first centuries

Displays of artificial geological artefacts may be accurate, but not always. Examination of restorations of Coal Measure (Upper Carboniferous, Pennsylvanian) strata in two public displays shows how standards vary. In Crystal Palace Park, London (opened 1854), Coal Measures are accurately displayed and explained in detail. These beds are faulted, and associated features such as nodular mudrocks are displayed, although the density of nodules may be inaccurate. In contrast, in the Dutch National Railway Museum, Het Spoorwegmuseum, Utrecht, the Netherlands (reopened 2005), the portrayal of Pennsylvanian strata (sandstones?) of north‐east England gives them a uniform colour and poor bedding. Although there is a reconstruction of part of a coal mine, coal(?) forms lenses, not beds, and is the same brown hue as the sandstone. Museums and theme parks need to pursue the expertise of knowledgeable local geologists if they are to accurately model geological phenomena.     

Fossils explained 78

The coastal town of Margate in north Kent, south-east England, is geologically well known, with extensive cliffs of chalk with locally common Upper Cretaceous fossils. But to the ichnologist the modern beach is at least as fascinating, with a trinity of borings in chalk clasts and mollusc shells posing interesting questions relevant to palaeoecology and taphonomy.     

Using urban geology: a field guide to Morpeth Railway Station,northern England

A railway station might not seem an obvious subject as a geological locality. Yet with ease of access (just catch a train), the geology of the building stones of a railway station offers certain advantages in the age of inaccessible quarries, and tiresome health and safety paperwork. Hammers can be left at home, and eyes, hand lenses, cameras and compass‐clinometers may all be applied for non‐destructive investigation.     

The Young Geographers And Their Research: 1936–1943*

The Young Geographers, an informal organization of American geographers, flourished from 1936 to 1943. One of its projects in 1940 and 1941 was the compilation and publication of lists of contemplated research by some 170 Young Geographers. Their listed research interests were relatively narrow in subject and geographical area. The successor of the Young Geographers was the American Society for Professional Geographers which merged with the Association of American Geographers in 1948 under a democratic constitution which assured that young geographers and their research would be recognized.     

Opening GIScience: A process-based approach

Many scholars have demonstrated growing interest in GIScience in recent years, including use of open data portals, shared code and options for open access publication. These practices have made both research and data more transparent and accessible for a broad audience. This research may be open only in a limited sense for populations without expertise in the technology and methods undergirding these data. Based on two case studies using RStudio’s Shiny web platform, we argue that a process-based approach focusing on how analysis is opened throughout the research process provides a supplementary way to define and reflect upon public facing geographic research. Reflecting upon decisions we made at key points in each case study project, we identify four key tensions inherent to work in open GIScience: standardized vs. flexible tools, expert vs. community-led design, single vs. multiple audiences and established vs. emerging metrics.     

Dielectric constants of crystalline and amorphous spodumene,anorthite and diopside and the oxide additivity rule

The dielectric constants and dissipation factors of LiAlSi₂O₆, CaAl₂Si₂O₈ and CaMgSi₂O₆ in both the crystalline (α-spodumene, anorthite, and diopside) and amorphous forms were determined at 1 MHz using a two-terminal method and empirically determined edge corrections. The results are: spodumene κ′ ₁₁=7.30 tan δ= 0.0007 κ′₂₂=8.463 tan δ= 0.0002 κ′₃₃ =11.12 tan δ= 0.0007 anorthite κ′ _a ^*=5.47 tan δ= 0.0009 κ′_b ^*=8.76 tan δ= 0.0010 κ′_c ^*=7.19 tan δ= 0.0013 diopside κ′₁₁=9.69 tan δ= 0.0016 κ′₂₂ = 7.31 tan δ= 0.0007 κ′₃₃=7.29 tan δ= 0.00019 LiAlSi₂O₆ κ′=8.07 tan δ= 0.047 amorphous CaAl₂Si₂O₈ κ′=7.50 tan δ= 0.0024 amorphous CaMgSi₂O₆ κ′=8.89 tan δ= 0.0021 amorphous The dielectric properties of a spodumene glass, progressively crystallized at different conditions, were also determined. As the crystallization temperature was increased from 720 to 920° C, κ′ increased from 6.22 to 6.44. The dissipation factor, tan δ, remained constant at 0.020. Similarly, as the crystallization time at 750° C increased from 0.5 hr to 6.0 hr, κ′ increased from 6.28 to 6.35. The deviations of the measured dielectric polarizabilities as determined from the Clausius-Mosotti equation from those calculated from the sum of oxide polarizabilities according to α _D(mineral, glass) = σ α _D(oxides) are +7.4% for α-spodumene, +1.2% for diopside, and +28.0, +19.6 and +15.9% for amorphous spodumene, anorthitie and diopside compositions, respectively. Positive deviations in α-spodumene and anorthite are consistent with lower than normal apparent cation bond valence sums and are believed to be evidence for loosely bonded “rattling” Li and Ca ions. Diopside, with Ca and Mg ions having normal bond valence sums, exhibits no abnormal deviation from additivity. Larger positive deviations in amorphous SiO₂, LiAlSi₂O₆, CaAl₂Si₂O₈ and CaMgSi₂O₆ are postulated to arise from a combination of loosely bonded cations and disordered O⁼ ions where the oxygen dielectric polarizability increased from its normal value of 2.0 ų in well-behaved oxides to 2.2–3.0 Å₃ in the amorphous phases.     

Spatial Distribution–Abundance Relationships in Juvenile (Age 0) Red Drum (<Emphasis Type="Italic">Sciaenops ocellatus</Emphasis>) and Spotted Seatrout (<Emphasis Type="Italic">Cynoscion nebulosus</Emphasis>). I: Influence of Freshwater Inflow

We examined relationships between freshwater inflow and population abundance and distribution of two size classes (15–50 mm Standard Length and 51–100 mm SL) of spotted seatrout (Cynoscion nebulosus) and red drum (Sciaenops ocellatus) over our 13-year study covering shallow waters of Tampa Bay and several adjacent rivers. Juveniles of seatrout were relatively abundant most years and broadly distributed primarily in the bay. Freshwater inflow was positively related to spatial distribution and abundance of smaller juveniles of seatrout, yet it was unrelated to the larger size class. Red drum juveniles were less abundant and narrowly distributed primarily within the rivers. Lower portions of the Alafia, Little Manatee, and Manatee Rivers—a combined area comprising only 2 % of the study area—contained 40–96 % of the annual population. Freshwater inflow was positively related to population distribution and abundance of larger red drum suggesting that reductions in inflow can reduce both habitat area and populations. Inflow was related to abundance but not distribution of the smaller red drum suggesting that inflow may increase habitat quality but perhaps not quantity at this earlier growth stage. Comparing spatial and population dynamics of multiple species can help prioritize them for conservation and management issues, such as freshwater inflow regulation. Reductions in inflow reduce populations and spatial distribution of at least one juvenile life stage of these two fishery species. Due to their narrow spatial distribution in the rivers, juveniles of red drum appear to be particularly vulnerable to modification of the riverine environment.     

Coupling bio-logging with nutritional geometry to reveal novel insights into the foraging behaviour of a plunge-diving marine predator

It is widely believed that predators maximise their energy intake while foraging and consume prey that are nutritionally similar. We combined GPS data loggers, miniaturised cameras, dietary sampling and nutritional geometry to examine the nutritional variability in the prey and selected diet, and foraging performance, of the masked booby (Sula dactylatra tasmani), a wild carnivore and marine top predator. Data loggers also revealed no significant differences between sexes in the foraging performance of chick-rearing adults. Females provided more food to their chicks than the males and, regardless of the nutritional variability of prey consumed, both sexes showed similar amounts of protein and lipid in their diets. Miniaturised cameras combined with nutritional analysis of prey provided, for the first time, fine-scale detail of the amounts of macronutrients consumed in each plunge dive and the overall foraging trip. Our methodology could be considered for future studies that aim to contribute to the general understanding of the behavioural and physiological mechanisms and ecological and evolutionary significance of animal foraging (e.g. energy expenditure budgets and prey selection for self- and offspring-feeding that could lead to sex-specific foraging strategies).