Ellinor Michel | Natural History Museum, London (original) (raw)

Rift Lake Biology - Tanganyika, Malawi, Baikal by Ellinor Michel

Symbiosis, 2012

We describe the first records of spirochetes in the gut of fourteen species of continental gastro... more We describe the first records of spirochetes in the gut of fourteen species of continental gastropods from a range of habitats and representing six families (Amnicolidae, Baicaliidae, Bithyniidae, Pyrgulidae, Lithoglyphidae and Benedictiidae). The bacteria were mainly found in the crystalline style sac, as has been reported in marine bivalves. The surveyed habitats include water bodies in North America and Eurasia, including deep water hydrothermal vent and gas hydrate zones in Lake Baikal. Spirochetes were present both in mature and young snails, but were not detected in embryos before hatching, indicating lateral transfer. The surveyed gastropods range in trophic strategy, including phyto-, detrito-and bacteriophagous grazers and filter feeders. Our results indicate that spirochetes are commensal in the surveyed gastropods with potential limited benefit and no detriment to the host animal. We suggest that the specialized internal habitat of the crystalline style sac in molluscs is likely to reveal unrecognized spirochete diversity that will shed new light on gastropod trophic ecology and spirochete diversity.

Freshwater Biology, 2011

1. Ecologists continue to debate whether the assembly of communities of species is more strongly ... more 1. Ecologists continue to debate whether the assembly of communities of species is more strongly influenced by dispersal limitations or niche-based factors. Analytical approaches that account for both mechanisms can help to resolve controls of community assembly. 2. We compared littoral snail assemblages in Lake Tanganyika at three different spatial scales (5–25 m, 0.5–10 km and 0.5–27 km) to test whether spatial distance or environ- mental differences are better predictors of community similarity.
3. At the finest scale (5–25 m), snail assemblages shifted strongly with depth but not across similar lateral distances, indicating a stronger response to environmental gradients than dispersal opportunities.
4. At the two larger scales (0.5–27 km), both environmental similarity and shoreline distance between sites predicted assemblage similarity across sites. Additionally, canonical correspondence analysis revealed that snail abundances were significantly correlated with algal carbon-to-nitrogen ratio and wave energy.
5. Our results indicate that the factors governing assemblage structure are scale dependent; niche-based mechanisms act across all spatial scales, whereas community similarity declines with distance only at larger spatial separations.

Hydrobiologia, 2011

We used multiple analytical methods to demonstrate resource partitioning in five species of coexi... more We used multiple analytical methods to demonstrate resource partitioning in five species of coexisting endemic gastropods in the family Baicaliidae and the genus Megalovalvata (Valvatidae) in rocky walls of the underwater canyons in Lake Baikal. We tested whether filter-feeding baicaliids and valvatids consume and assimilate different food using data from gut contents, stable d13C and d15N isotopes and radular morphology, with subsequent combined analyses. Our results showed that the four baicaliid species assimilate microalgae, diatoms and bacteria, whereas the single Megalovalvata species mostly assimilates plant detritus. The d15N variations in the baicaliids reflect differences in their digestion of seston components, whereas the d13C similarity illustrates consumption of food particles derived from similar primary producers. Gut contents in the baicaliids were dominated by a single species of planktonic diatom, although more than 30 species of microalgae were recorded in all seasons. However, the composition and quantity of additional food particles varied by species. Our results showed that baicaliids have significant fine scale differences in radular tooth morphology, which may allow parti- tioning of food resources.

Molecular Phylogenetics and Evolution, 2011

Sponges are a conspicuous element in many benthic habitats including in Africa’s oldest, deepest ... more Sponges are a conspicuous element in many benthic habitats including in Africa’s oldest, deepest lake, Lake Tanganyika. Despite their prevalence and pivotal ecological role as filter feeders, knowledge of the evolutionary history of sponges is in its infancy. Here, we provide the first molecular analysis target- ing the evolution of sponges from Lake Tanganyika. Independent markers indicate the occurrence of sev- eral colonisation events which have shaped the current Tanganyikan lacustrine sponge biodiversity. This is in contrast to a range of previously studied organisms that have diversified within the lake from single lineages. Our tree reconstructions indicate the presence of two genera, Oncosclera and Eunapius, which are globally distributed. Therefore, we reject the hypothesis of monophyly for the sponges from Lake Tanganyika and challenge existing higher taxonomic structure for freshwater sponges.

We studied the effects of upwelling on nutrient and phytoplankton dynamics in the pelagic and lit... more We studied the effects of upwelling on nutrient and phytoplankton dynamics in the pelagic and littoral zones of Lake Tanganyika near Kigoma, Tanzania. During the dry season of 2004, a rise in the thermocline and sudden drop in surface water temperatures indicated a substantial upwelling event. Increases in concentrations of nitrate, soluble reactive phosphorus, and silica in the surface waters occurred simultaneously after the temperature drop. Within days, chlorophyll a concentrations increased and remained elevated, while inorganic nutrient concentrations returned to preupwelling levels and organic nutrient concentrations peaked. We observed parallel temporal patterns of water temperature, nutrient concentrations, and phytoplankton chlorophyll in both the pelagic and the littoral zones, demonstrating that upwelling strongly affects the nearshore ecosystem as well as the pelagic zone. Concurrent records from 12 littoral sites indicated spatial variation in the timing, magnitude, and biological response to upwelling. There was no discernable latitudinal pattern in the timing of upwelling, suggesting that mixing did not result from a progressive wave. Our monitoring, as well as other multiyear studies, suggests that dry-season upwelling occurs during most years in northern Lake Tanganyika. The observed sensitivity of littoral nutrients and phytoplankton to upwelling suggests that reductions in upwelling due to global climate change could strongly affect the dynamics of the spectacular nearshore ecosystem of Lake Tanganyika, as has been proposed for the pelagic zone.

Aquatic Biology, 2009

Quantitative measures of feeding, respiration, growth and reproduction were brought together to a... more Quantitative measures of feeding, respiration, growth and reproduction were brought together to achieve an overview of differences in physiology between 2 sympatric species of Anisus (Gastropoda, Planorbidae) in subarctic Lake Krivoye, northwestern Russia. This is a resource-limited lake with a short summer growing season where one might expect intense competition for resources among the numerous snails. Because coexistence is a multidimensional process, we have aimed to quantify bioenergetic variables related to several different major physiological functions. Using experiments that manipulated detritus and periphyton, we showed that both species consume detri- tus in combination with algae, but used different feeding strategies. Anisus contortus has a steeper growth allometry, greater specific growth rate and faster reproductive cycle. Anisus acronicus, how- ever, has a faster absolute growth rate and longer life cycle, which results in its dominance in biomass and numbers. Although bioenergetics in general cannot be used to test directly for competition between closely related species, we have shown alternative growth and energy-metabolism strate- gies used by different species in a common habitat. Indicators of niche partitioning, maintained by balance calculations, included differences in preferences, quality and consumption rate of consumed food. We expect that these differences are not only important in proximal coexistence, but may also present alternatives for surviving long-term changes in the lake’s productivity and habitat types.

Functional Ecology, 2009

1. Among vertebrates, herbivores have longer digestive tracts than animals at higher trophic leve... more 1. Among vertebrates, herbivores have longer digestive tracts than animals at higher trophic levels, a pattern thought to reflect a trade-off between digestive efficiency and tissue maintenance costs. However, phylogenetic influences on this pattern have rarely been considered. Taxa that have undergone diversification accompanied by dietary shifts provide a powerful opportunity to examine the relationship between diet and intestine length while accounting for phylogeny.
2. In this paper we assess the relationship between diet and intestine length in the cichlid fishes of Lake Tanganyika, which are renowned for their diversity of species and trophic strategies.
3. First, we test the effect of trophic position on intestine length across 32 species, while controlling for phylogeny. Trophic position was inferred from nitrogen stable isotopes, which provide a temporally integrated, quantitative perspective on the complex diets of tropical fish. Second, we examine patterns of intraspecific variation in intestine length of an algivorous cichlid (Tropheus brichardi) along a natural spatial gradient in algal nitrogen content.
4. Trophic position explains 51% of size-standardized variation in intestine length after accounting for phylogeny. Accounting for phylogeny does not substantially alter the relationship between trophic position and intestine length, despite the existence of phylogenetic signal in both traits. Thus, diet is a strong predictor of variation at the interspecific level.
5. There is a striking inverse relationship between intestine length and algal nutrient content among populations of T. brichardi, suggesting substantial plasticity in response to food quality, and thus a strong dietary influence on patterns of intraspecific variation.
6. Diet is a strong predictor of intestine length at both intra- and interspecific scales, indicating that fish adjust their phenotype to balance nutritional needs against energetic costs. Further- more, functional explanations for trophic diversification of cichlid fishes in the African Great Lakes have long focused on jaw structures, but our results indicate that intestinal plasticity in response to diet quality may also be an important mechanism for accommodating trophic shifts during evolutionary radiations.

Hydrobiologia, 2008

The endemic crabs of Lake Tanganyika include a phenotypically diverse clade that exhibits recent ... more The endemic crabs of Lake Tanganyika include a phenotypically diverse clade that exhibits recent divergence and low phylogenetic species resolution. There are indications that ecological niche segregation has played a prominent role in the divergence of this clade. We used habitat surveys, gut content analyses and stable isotope analyses to test the extent to which morphological species are ecologically different. Our data show some interspe- cific segregation in depth, substrate type and mean stable isotope signatures. At the same time, a considerable level of ecological niche overlap is evident among species of Platythelphusa that coexist in rocky littoral habitats. We consider these results in the framework of adaptive radiation theory, and we discuss general ramifications for the maintenance of species diversity in Lake Tanganyika.

Biodiversity & Conservation, 2008

Sedimentation resulting from riparian deforestation has a wide range of detrimental effects on aq... more Sedimentation resulting from riparian deforestation has a wide range of detrimental effects on aquatic biodiversity, but predicting the full consequences of such disturbances requires an understanding of the ecosystem’s key functional components. We investigated the ecology and response to sedimentation of the diverse, endemic freshwater crabs of Lake Tanganyika, which may occupy important positions in littoral foodwebs. Our surveys revealed crab distribution patterns to be patchy, and that crabs can be locally abundant (0–28 individuals/m2). Crab densities decreased with depth and the dry mass of crab assemblages ranged from 0.0 to 117.7 g/m2. Comparisons among sites revealed significant effects of sedimentation on crab assemblage evenness, but provided no evidence that sedimentation has altered densities, incidence or species richness. The resilience of crabs to sedimentation might be related to their intraspecific dietary breadth. Stable isotope data (delta-13C and delta-15N) from crabs and their potential food resources indicated differences in trophic roles among endemic crab species. Overall, crabs occupy higher trophic positions than most other invertebrates, and they draw upon both benthic and planktonic energy pathways. The high biomass and top-predator status of some crab species suggests the potential for cascading effects on organisms lower in the food web.

Journal of Molluscan Studies, 2007

Endemic Lavigeria gastropods are diverse and common in the benthos of Lake Tanganyika. We used in... more Endemic Lavigeria gastropods are diverse and common in the benthos of Lake Tanganyika. We used in situ studies of marked individuals to quantify rates of daily movement by three species, and test the effects of size, sex, reproductive status and parasitism on movement. Average net travel distance was 50 cm day21, which corresponds to about 20 times shell length. Male L. coronata moved significantly farther than L. coronata females or L. grandis, and L. nassa of either sex. There were also significant differ- ences among individuals within each group; however, these differences were not predicted by size, repro- ductive status or parasitism. We interpret greater movement of L. coronata males as a reflection of mate searching; the ratio of males to non-brooding, non-parasitized females was three times as high in L. coronata (21:1) as in the other species (6:1). Our results indicate that these snails are capable of moving considerable distances, and that the highly localized distribution of L. coronata populations is not simply a reflection of limited movement by individual snails.

Biological Invasions, 2008

Successful establishment and spread of biological invaders may be promoted by the absence of popu... more Successful establishment and spread of biological invaders may be promoted by the absence of population-regulating enemies such as pathogens, parasites or predators. This may come about when introduced taxa are missing enemies from their native habitats, or through immunity to enemies within invaded habitats. Here we provide field evidence that trematode parasites are absent in a highly invasive morph of the gastropod Melanoides tuberculata in Lake Malawi, and that the invasive morph is resistant to indigenous trematodes that castrate and induce gigantism in native M. tuberculata. Since helminth infections can strongly influence host population abundances in other host-parasite systems, this enemy release may have provided an advantage to the invasive morph in terms of reproductive capacity and survivorship.

Moecular Ecology, 2007

Exceptional ecological niche diversity, clear waters and unique divergent selection pres- sures h... more Exceptional ecological niche diversity, clear waters and unique divergent selection pres- sures have often been invoked to explain high morphological and genetic diversity of taxa within ancient lakes. However, it is possible that in some ancient lake taxa high diversity has arisen because these historically stable environments have allowed accumulation of lineages over evolutionary timescales, a process impossible in neighbouring aquatic habi- tats undergoing desiccation and reflooding. Here we examined the evolution of a unique morphologically diverse assemblage of thiarid gastropods belonging to the Melanoides polymorpha ‘complex’ in Lake Malawi. Using mitochondrial DNA sequences, we found this Lake Malawi complex was not monophyletic, instead sharing common ancestry with Melanoides anomala and Melanoides mweruensis from the Congo Basin. Fossil calibrations of molecular divergence placed the origins of this complex to within the last 4 million years. Nuclear amplified fragment length polymorphism markers revealed sympatric M. poly- morpha morphs to be strongly genetically differentiated lineages, and males were absent from our samples indicating that reproduction is predominantly parthenogenetic. These results imply the presence of Lake Malawi as a standing water body over the last million years or more has facilitated accumulation of clonal morphological diversity, a process that has not taken place in more transient freshwater habitats. As such, the historical stability of aquatic environments may have been critical in determining present spatial distributions of biodiversity.

Tentacle, 2007

Creeping invasive: The threat of an introduced Melanoides gastropod in Lake Malawi. Ellinor Mi... more Creeping invasive: The threat of an introduced Melanoides gastropod in Lake Malawi.

Ellinor Michel, Martin Genner, Jonathan Todd

As part of an expanding effort of species discovery, delineation and description of the endemic thiarid gastropods of Lake Malawi, a surprising discovery was made that underscores the importance of accurate, fine-scaled species recognition. Results from a combination of molecular and morphological work revealed that Lake Malawi harbours not only a number of native lineages of Melanoides gastropods but also an invasive Melanoides (Genner et al. 2004). Among the natives to the Lake Malawi basin, the group Melanoides polymorpha includes, as you might guess from the specific name ‘polymorpha’, huge morphological diversity. ‘Morphs’ of these are potentially identifiable as ‘species equivalents’ as they are strongly genetically differentiated based on AFLPs, however their reproduction is primarily asexual (Genner et al. 2007a), so their equivalence to ‘standard’ species (e.g. those defined under the biological species concept) is somewhat debatable. There is also a second native Melanoides whose shell looks quite distinct from those of the various M. polymorpha morphs and is commonly identified as M. tuberculata (e.g., Brown 1994). Additionally, DNA sequence results have uncovered a third separate lineage of Melanoides that is identical to M. tuberculata native to SE Asia. We have termed this a camouflaged invasion, as the new M. tuberculata looks similar to the native M. tuberculata on first glance, however it can be recognized by subtle but distinctive shell characters.

The absence of this invasive snail from historic museum collections indicates that it arrived in Lake Malawi recently, certainly in the last 25 years and potentially as an introduction through the ornamental fish trade. Moreover this invasive M. tuberculata is becoming extremely common (Genner et al. 2004). It is not only possibly displacing members of the other Melanoides gastropods native to the area, but its sheer abundance may be influencing other aspects of the lacustrine ecology of the region. The photograph shows a recent haul from Lake Malombe, a large peripheral water body of Lake Malawi. Here fishers use ‘nkatcha nets’, fine-meshed bottom-weighted seines set at approximately 5m depth before being pulled together at the base by a swimmer. This net drags up everything, which is landed and sold by the tin bucket-load (left-hand side of the picture). Buyers dump the catch on the ground and pick the fish from the snails. The landing beaches are now carpeted with a thick layer of dried or decomposing invasive Melanoides tuberculata. In 1996 the fishers of Malombe caught only fish (MG pers. obs.). We hypothesize that among the many possible reasons for the rapid expansion of this invasive is release from parasite pressure, as our work has shown that the invasive Melanoides is unexpectedly free from the parasites common to native thiarid gastropods (Genner et al. 2007b). The invasive snail has also recently been found in Lake Chilwa, a huge shallow lake in a neighbouring catchment. Future colonisations of freshwaters throughout the region are likely. This is a point of conservation concern for the benthic ecosystem functioning in Lake Malawi, which includes other endemic gastropods, fish and crustaceans.

Brown, D.S. (1994) Freshwater Snails of Africa and their Medical Importance. 2nd ed. Taylor & Francis, London.

Genner, M.J., Michel, E., Erpenbeck, D., de Voogd, N., Witte, F. & Pointier, J-P. (2004) Camouflaged invasion of Lake Malawi by an oriental gastropod. Molecular Ecology 13, 2135-2141.

Genner, M.J., Todd, J.A., Michel, E., Erpenbeck, D., Joyce, D.A., Jimoh, A., Piechocki, A. & Pointier J-P. (2007) Amassing diversity in an ancient lake: Evolution of a morphologically diverse parthenogenetic gastropod assemblage in Lake Malawi. Molecular Ecology 16, 517–530.

Genner, M.J., Michel, E. & Todd, J.A. (2007) Resistance of an invasive gastropod to an indigenous trematode parasite in Lake Malawi. Biological Invasions. (doi: 10.1007/s10530-007-9105-1).

Molecular Phylogenetics and Evolution, 2006

Limnology and Oceanography, 2006

We studied the effects of nutrient availability and grazers on periphyton in the littoral zone of... more We studied the effects of nutrient availability and grazers on periphyton in the littoral zone of Lake Tanganyika. Using a combination of dissolved nutrient ratios, nutrient diffusing substrates, and benthic productivity responses to nutrient supplementation, we evaluated whether nitrogen (N) or phosphorus (P) limited periphyton productivity near Kigoma, Tanzania, during the dry seasons of 2001 and 2002. The relative effects of grazers and nutrients on periphyton were quantified by manipulating grazer access to nutrient diffusing substrates. We found very low ambient concentrations of inorganic N and soluble reactive P, but generally higher concentrations of dissolved organic nutrients. Nutrient diffusing substrates indicated a shift from P limitation in 2001 to co-limitation by N and P in 2002, probably as a consequence of unusual coastal upwelling in 2002. Productivity responses of natural epilithic algae to nutrient supplementation also indicated N–P co-limitation in 2002. However, fish and other large grazers had much stronger effects on periphyton than nutrients. Grazers strongly suppressed periphyton biomass, but had weaker negative effects on area-specific gross primary productivity as a result of large increases in biomass-specific gross primary productivity. We conclude that littoral nutrient availability influenced periphyton productivity, but that top-down control predominated.

Conservation Biology, 2005

Human impacts on aquatic biodiversity are often measured at the assemblage or community level, al... more Human impacts on aquatic biodiversity are often measured at the assemblage or community level, although it has been suggested that individual-level measures are more sensitive. We evaluated the effects of anthropogenic sedimentation on endemic snails in Lake Tanganyika, East Africa, by comparing assemblage- level (i.e., species richness, evenness, and abundance) and individual-level (i.e., frequencies of predation and parasitism, fecal organic content, life history) data between sediment-disturbed and reference sites. Previous studies have indicated that sedimentation kills snails and reduces mollusc diversity in this system, but we found little evidence of changes in species richness, evenness, or snail abundance at the levels of sedimentation recorded. In contrast, individual-level data revealed a variety of differences associated with sedimentation. Frequencies of shell scarring by predatory crabs and castration by parasitic trematodes were significantly lower at disturbed sites, indicating shifts in interspecific interactions. Snails ingested large amounts of inorganic sediments at disturbed sites, suggesting a reduction in food quality. In addition, sedimentation was associated with a large downward shift in size distribution within some species and reproduction at smaller size. These strong patterns in individual-level data contrast with the lack of effects at the assemblage level. We argue that incorporating individual-level measures will often enhance the sensitivity of impact surveys and may reveal effects of disturbance on important interspecific interactions.

Journal of Molluscan Studies, 2004

A thiarid gastropod, Vinundu westae new genus and new species, is described from Lake Tanganyika,... more A thiarid gastropod, Vinundu westae new genus and new species, is described from Lake Tanganyika, and the species Nassopsis guillemei Martel & Dautzenberg, 1899 is transferred to this new genus from Edgaria (=Lavigeria). The shell of Vinundu has equal axial and spiral macrosculpture, producing characteristic regular nodes at the sculptural intersections. Reproduction in Vinundu is oviparous, in contrast to the ovoviviparous habit of its sister group, Lavigeria. Radular teeth and isotope values indicate that this is a grazer. Vinundu species are readily distinguished from their sister clade Lavigeria by conchological, anatomical and molecular characters. The two Vinundu species are common in deep water, rocky habitats of this clear-water, ancient lake.

Journal of Conchology, 2003

The Lake Tanganyika benthos presents a highly biodiverse system on many spatial scales. We presen... more The Lake Tanganyika benthos presents a highly biodiverse system on many spatial scales. We present here an analysis of regional ( ) diversity and local ( ) diversity of the Lavigeria species flock, the most common and speciose of the endemic gastropods, across the currently accessible sections of lakeshore. We found significant differences in Lavigeria gastropod diversity among regions within the lake, and that regional species richness was strongly associated with the presence of local, short-range endemics. Species richness at individual sites was not correlated with total species richness of the surrounding region. Although sites frequently encompassed high sympatry of congeneric species, highly disjunct species distributions lead to non-predictable community assemblages.

Molecular Ecology, 2004

In this study we report the first animal invasion, to our knowledge, into Lake Malawi.The coloni... more In this study we report the first animal invasion, to our knowledge, into Lake Malawi.The colonizer is a non-native morph of the gastropod Melanoides tuberculata that differs substantially in external shell characters from co-occurring indigenous forms. However,because the species possesses extensive within-Africa geographical variation in shell morphology, it was unclear whether the invasion was range expansion of a native African morph, or a colonization from elsewhere. Mitochondrial DNA sequences indicate a south-east Asian origin for the invader, suggesting that shell variation found among indigenous allopatric populations camouflaged an intercontinental invasion.

Journal of Biogeography, 2004

Current estimates of species richness within rapidly evolving species flocks are often highly dep... more Current estimates of species richness within rapidly evolving species flocks are often highly dependent on the species status of allopatric populations that differ in phenotypic traits. These traits may be unreliable indicators of biological species status and systematists may have inconsistently assigned species among lineages or locations on the basis of these traits, thus hampering comparative studies of regional species richness and speciation rates. Our aim was to develop a method of generating standardized estimates of regional species richness suitable for comparative analysis, and to use these estimates to examine the extent and consistency of species assignment of allopatric populations within rapidly evolving cichlid fish flocks present in three east African lakes.

Symbiosis, 2012

Freshwater Biology, 2011

Hydrobiologia, 2011

Molecular Phylogenetics and Evolution, 2011

Aquatic Biology, 2009

Functional Ecology, 2009

Hydrobiologia, 2008

Biodiversity & Conservation, 2008

Journal of Molluscan Studies, 2007

Biological Invasions, 2008

Moecular Ecology, 2007

Tentacle, 2007

Creeping invasive: The threat of an introduced Melanoides gastropod in Lake Malawi. Ellinor Mi... more Creeping invasive: The threat of an introduced Melanoides gastropod in Lake Malawi.

Ellinor Michel, Martin Genner, Jonathan Todd

Brown, D.S. (1994) Freshwater Snails of Africa and their Medical Importance. 2nd ed. Taylor & Francis, London.

Genner, M.J., Michel, E., Erpenbeck, D., de Voogd, N., Witte, F. & Pointier, J-P. (2004) Camouflaged invasion of Lake Malawi by an oriental gastropod. Molecular Ecology 13, 2135-2141.

Genner, M.J., Michel, E. & Todd, J.A. (2007) Resistance of an invasive gastropod to an indigenous trematode parasite in Lake Malawi. Biological Invasions. (doi: 10.1007/s10530-007-9105-1).

Molecular Phylogenetics and Evolution, 2006

Limnology and Oceanography, 2006

Conservation Biology, 2005

Journal of Molluscan Studies, 2004

Journal of Conchology, 2003

Molecular Ecology, 2004

Journal of Biogeography, 2004

Palaeogeography, Palaeoclimatology, Palaeoecology, 2013

Much of the spectacular biodiversity of the African Great Lakes is endemic to single lake basins ... more Much of the spectacular biodiversity of the African Great Lakes is endemic to single lake basins so that the margins of these basins or their lakes coincide with biogeographic boundaries. Longstanding debate surrounds the evolution of these endemic species, the stability of bioprovinces, and the exchange of faunas between them over geologic time as the rift developed. Because these debates are currently unsettled, we are uncertain of how much existing distribution patterns are determined by modern hydrological barriers versus reflecting past history. This study reports on late Quaternary fossils from the Rukwa Basin and integrates geological and paleoecological data to explore faunal exchange between freshwater bioprovinces, in particular with Lake Tanganyika. Lake Rukwa’s water level showed large fluctuations over the last 25 ky, and for most of this period the lake contained large habitat diversity, with different species assemblages and taphonomic controls along its northern and southern shores. Comparison of fossil and modern invertebrate assemblages suggests faunal persistence through the Last Glacial Maximum, but with an extirpation event that occurred in the last 5 ky. Some of the molluscs and ostracodes studied here are closely related to taxa (or part of clades) that are currently endemic to Lake Tanganyika, but others testify to wider and perhaps older faunal exchanges between the Rukwa bioprovince and those of Lake Malawi and the Upper Congo (in particular Lake Mweru). The Rukwa Basin has a long history of rifting and lacustrine conditions and, at least temporarily, its ecosystems appear to have functioned as satellites to Lake Tanganyika in which intralacustrine speciation occurred. Paleontological studies of the Rukwa faunas are particularly relevant because of the basin’s important role in the late Cenozoic biogeography of tropical Africa, and because many of the molecular traces potentially revealing this history would have been erased in the late Holocene extirpation.

Chapter in O. W. Baganz, Y. Bartov, K. Bohacs, and D. Nummedal, eds., Lacustrine sandstone reservoirs and hydrocarbon systems: AAPG Memoir 95, p. 433–489., 2012

Actualistic studies of modern continental environments and the spatial and temporal distribution ... more Actualistic studies of modern continental environments and the spatial and temporal distribution of terrestrial and aquatic organisms are summarized and synthesized to understand
how to better interpret the significance of trace fossils to differentiate lacustrine from fluvial, eolian, and marine deposits in the geologic record. The purpose of this approach is to develop
an understanding of the physicochemical factors that control the occurrence, diversity, abundance, and tiering of organism behavior and parallels what is known for benthic and other trace-making organisms in marine environments. The distribution of traces observed in Lake Tanganyika and Lake Eyre, an overfilled lake in a tropical rift basin setting and an underfilled lake in an arid mid-latitude ephemeral playa setting, respectively, are described, synthesized, and compared with the Mermia, Coprinisphaera, Termitichnus, Skolithos, and Scoyenia ichnofacies models proposed for continental environments. The comparisons show that all the models are inappropriate for the fluvial-lacustrine settings of Lake Tanganyika and Lake Eyre because the models do not support the environmental uniqueness or distinctive collection of traces across these environments, nor do they provide sufficient interpretive power. The multiple ichnocoenoses for each subenvironment observed in the balanced-filled and underfilled lacustrine systems more accurately record the environmental uniqueness and distinctive collection of traces found in each environment. Ichnocoenoses are better suited for continental depositional systems and their environments because they reflect the nature of processes and distribution of life in continental settings, which are inherently heterogeneous spatially and
temporally. Ichnocoenoses also provide sufficient interpretive power for trace-fossil associations formed under different physicochemical conditions for each type of environment. General
trends in trace-fossil diversity, abundance, distribution, and tiering are predicted for alluvial (fluvial), lacustrine, and eolian environments so that new models based on the distribution
of ichnocoenoses and their sedimentary and pedogenic characteristics from outcrop and core can be constructed.

Palaios, 2010

Lake Tanganyika, the world’s largest tropical rift lake, is unique among its counterparts in East... more Lake Tanganyika, the world’s largest tropical rift lake, is unique among its counterparts in East Africa for the remarkable diversity of mollusk-rich sediments in its littoral zone. Molluscan shell beds are, however, a common feature of ancient lacustrine rift deposits and thus a better understanding of their spatial and temporal development is important. Targeted surveys across the littoral region of the Kigoma Basin reveal three surficial shell- rich facies that differ widely in depositional style and geometry. A unifying characteristic of these deposits is the volume of shells of Neothauma tanganyicense, a large, viviparous gastropod endemic to the lake. Reservoir-corrected radiocarbon dating indicates that Neothauma deposits in these surficial sediments are time averaged over at least the last ,1600 calendar years BP. Preservation of fossil Neothauma shells in the littoral zone depends on both environmental conditions and on post-mortem shell modifications. Interaction between shells and mobile siliciclastic grains, facilitated by wave action and storms, represents a particularly destructive taphonomic process in the study area. Rank scoring of damage to Neothauma suggests that stromatolitic encrustations or early calcite coatings may help mitigate shell destruction caused by hydraulic fragmentation and abrasion. Persistence of Neothauma in littoral beds has important implications for the structuring of specialized communities of shallow-water benthos, as well as for improving analog models for hydrocarbon reservoirs in lacustrine carbonates.

BioScience, 2011

Natural history collections (NHCs) are an important source of the long-term data needed to unders... more Natural history collections (NHCs) are an important source of the long-term data needed to understand how biota respond to ongoing anthropogenic climate change. These include taxon occurrence data for ecological modeling, as well as information that can be used to reconstruct mechanisms through which biota respond to changing climates. The full potential of NHCs for climate change research cannot be fully realized until high-quality data sets are conveniently accessible for research, but this requires that higher priority be placed on digitizing the holdings most useful for climate change research (e.g., whole-biota studies, time series, records of intensively sampled common taxa). Natural history collections must not neglect the proliferation of new information from efforts to understand how present-day ecosystems are responding to environmental change. These new directions require a strategic realignment for many NHC holders to complement their existing focus on taxonomy and systematics. To set these new priorities, we need strong partnerships between NHC holders and global change biologists.

Trends in Ecology and Evolution, 2011

In the otherwise excellent special issue of Trends in Ecology and Evolution on long-term ecologic... more In the otherwise excellent special issue of Trends in Ecology and Evolution on long-term ecological research (TREE 25(10), 2010), none of the contributors mentioned the importance of natural history collections (NHCs) as sources of data that can strongly complement past and ongoing survey data. Whereas very few field surveys have operated for more than a few decades, NHCs, conserved in museums and other institutions, comprise samples of the Earth’s biota typically extending back well into the nineteenth century and, in some cases, before this time. They therefore span the period of accelerated anthropogenic habitat destruction, climate warming and ocean acidification, in many cases reflecting baseline conditions before the major impact of these factors.

NHM internal SIF report by the Climate Change Working Group ('High Water Club'), 2010

ANCHORING BIODIVERSITY INFORMATION Names are our primary framework for organizing information on ... more ANCHORING BIODIVERSITY INFORMATION Names are our primary framework for organizing information on the living world. But how do we tie scientific names to a foundation so they provide stability and repeatability to otherwise fluid conceptual topics such as taxonomies? Biodiversity informatics aims to solve this issue, and its founding father was Charles Davies Sherborn. His magnum opus Index Animalium provided the bibliographic foundation for current zoological nomenclature. In the 43 years he spent working on this extraordinary resource, he anchored our understanding of animal diversity through the published scientific record. No work has equaled it and it is still in current, and critical, use. This volume celebrates Sherborn, his contributions, context and the future for the discipline of biodiversity informatics. The papers in this volume fall into three general areas. Papers in the first section present facets of Sherborn as a man, scientist and bibliographer, and describe the historical context for taxonomic indexing from the 19th century to today. Papers in the second section discuss current tools and innovations for bringing legacy biodiversity information into the modern age. The final section tackles the future of biological nomenclature, including digital access, innovative publishing models and the changing tools and sociology needed for communicating taxonomy.

ZooKeys - Special Issue Book, 2016

Charles Davies Sherborn provided the bibliographic foundation for current zoological nomenclature... more Charles Davies Sherborn provided the bibliographic foundation for current zoological nomenclature with his magnum opus Index Animalium. In the 43 years he spent working on this extraordinary resource, he anchored our understanding of animal diversity through the published scientific record. No work has equaled it and it is still in current, and critical, use.

Until now, Sherborn’s contribution has been recognized and relied upon by professional taxonomists worldwide but he has escaped the celebration of his accomplishment that is his due. This changed on 28 October 2011, with a symposium held in his honour at the Natural History Museum (NHM), London, on the 150th year of his birth. The symposium was organized by the International Commission on Zoological Nomenclature (ICZN), in collaboration with the Society for the History of Natural History (SHNH). The full-day meeting included an international panel of experts on bibliography and biodiversity bioinformatics who linked a view of the past with an active debate on the future of these related fields. There were fifteen talks from distinguished speakers from around the world, and ten posters, including an exhibition of ‘Sherborniana’, or artifacts from Sherborn’s tenure at the NHM. This volume expands on that meeting, with contributions from most of the presenters and selected additional contributors. The global and temporal reach of this event was extended through high quality recordings of all the talks, posters and discussion, including slides and poster downloads, through this site: http://backdoorbroadcasting.net/2011/10/anchoring-biodiversity-information-from-sherborn-to-the-21st-century-and-beyond/ and videos of all the talks through http://www.iczn.org/Sherborn.

The papers in this volume fall into three general areas. In the first section, seven papers present different facets of Sherborn as a man, scientist and bibliographer, and describe the historical context for taxonomic indexing from the 19th century to today. In the second section, five papers (with a major appendix) discuss current tools and innovations for bringing legacy information into the modern age. The final section, with three papers, tackles the future of biological nomenclature, including innovative publishing models and the changing tools and sociology needed for communicating taxonomy.

Because this volume is being produced as both a bound book and set of independent, Open Access papers free to download from the Web, there is a degree of overlap in some of the material covered. The papers need to be able to stand on their own, as well as to weave in to the whole overview of the accomplishments of this great man, his legacy and the roadmap for the future. In addition, because of the varied topics, the papers vary in style and length, some being more literary, some historical, some technical and some philosophical. Some are richly illustrated, others not at all. The only instructions to the authors were to attempt to reference each other’s papers to the greatest practical degree, simulating the kind of cross-topic communication one might have by being present at a symposium. The papers were all peer reviewed - most had critical input from three independent specialists in the field. I hope this diversity of approaches, rigorous oversight and the cross-pollination make the volume stimulating to read as a whole.

ZooKeys special issue - book, 2016

In: Smart P., Maisonneuve H. and Polderman A. (eds) Science Editors’ Handbook European Association of Science Editors. www.ease.org.uk, 2013

The International Code of Zoological Nomenclature (the Code) is the internationally agreed set of... more The International Code of Zoological Nomenclature (the Code) is the internationally agreed set of rules for the scientific names of animals that ensures the stability and universality of zoological names. This chapter is a brief overview of selected topics of special relevance to editors, based on their mention in the Code or prevalence in enquiries to the Commission and Secretariat.1 We cannot cover all the issues you might encounter, but more detail can be found in the following documents published by the International Commission on Zoological Nomenclature, which together comprise the authoritative, current, amended text of the Code: The 4th edition of the Code2, Declaration 443 and the Amendment of Articles.4 We suggest that your journal’s Instructions to Authors state that nomenclature must follow the current (4th) edition of the Code, taking into account later amendments, and give the web address of the Commission where the online Code, amendments and a selection of FAQs addressing common problems can be accessed (http://iczn.org/).

Bulletin of Zoological Nomenclature, 2011

The International Commission on Zoological Nomenclature, also known as the ‘ICZN’ and ‘the Commis... more The International Commission on Zoological Nomenclature, also known as the ‘ICZN’ and ‘the Commission’, supports editors of technical journals in applying best practice to zoological nomenclature.
This paper brings together selected topics of relevance to editors based on mentions of editors in the Code and experience of recent enquiries received by the ICZN Secretariat. It is necessarily technical but includes selected examples. Some topics could not be covered in detail but the Commission website has the complete and authoritative text of the 4th edition of the International Code of Zoological Nomenclature, also known as ‘the Code’, and a selection of FAQs:
What is the remit of the ICZN?; What is the code?; How should zoological names be written?; What are type specimens for?; What is the diðerence between availability and validity of names?; I think I have a new species, how can I get it named?; If a name is incorrectly spelled, what do I do?; What are the critical works in zoological nomenclature?; Who is the type of Homo sapiens?; Is there such thing as ‘page priority’?; What is the status of ZooBank and registration?; Selling scientific names; Should I use Phylocode?; What is the status of the ICZN ruling on electronic-only publication of nomenclatural acts?; How can I help the ICZN?
We advise editors to state that nomenclature must follow the 4th edition of the Code (1999) in your instructions to authors. We recommend that you cite the web address of the Commission where the online version of the Code can be accessed: http://iczn.org.

ZooKeys, 2011

The International Commission of Zoological Nomenclature has used the Scratchpads platform (curren... more The International Commission of Zoological Nomenclature has used the Scratchpads platform (currently being developed and maintained by ViBRANT) as the foundation for its redesigned website and as a platform for engaging with its users. The existing Scratchpad tools, with extensions to provide additional functions, have allowed for a major transformation in presentation of linked nomenclatural tools. Continued development of the new website will act as a springboard for the ICZN to participate more fully in the wider community of biodiversity informatics.

ZooKeys, 2012

A set of terms recommended for use in facilitating communication in biological nomenclature is pr... more A set of terms recommended for use in facilitating communication in biological nomenclature is pre- sented as a table showing broadly equivalent terms used in the traditional Codes of nomenclature. These terms are intended to help those engaged in naming across organism groups, and are the result of the work of the International Committee on Bionomenclature, whose aim is to promote harmonisation and com- munication amongst those naming life on Earth.

Bulletin of Zoological Nomenclature, 2011

in Letters to Linneaus, Eds. Q. Wheeler & S. Knapp, Linnean Society Special Publications, pp. 133-137., 2009

Bulletin of Zoological Nomenclature, 2009

In Systema Naturae 250 – A quarter millennium of zoological nomenclature, Ed. Polaszek, Taylor & Francis, London., 2010

"The ‘Linnaean Enterprise’, begun by Carolus Linnaeus in the mid-eighteenth century, stands as on... more "The ‘Linnaean Enterprise’, begun by Carolus Linnaeus in the mid-eighteenth century, stands as one of the most enduring (and arguably among the most important) scientific endeavors in human history: the quest to catalog all living species. During the 250 years since, this Enterprise has expanded in zoological content through a series of initiatives, including the Zoological Record, Sherborn’s Index Animalium, von Schulze’s Nomenclator Animalium and Neave’s Nomenclator Zoologicus. More recently, with the advent of computers and the internet, ambitious initiatives such as the Catalog of Life and Encyclopedia of Life have made great strides towards realizing Linnaeus’ original vision. In 2005, the ICZN Secretariat and Commissioners took one more step towards achieving this grand endeavor by proposing “ZooBank” as a web-based registry of zoological names and nomenclatural acts.
The ZooBank web site was launched as a prototype on January 1st, 2008, coinciding with the 250th anniversary of the official start of Zoological Nomenclature. At its launch, the ZooBank registry included all 4,819 names established in the 10th edition of Linnaeus’ Systema Naturae, as well as five new fish species names established in an article published concurrently with the launch of ZooBank. ZooBank is not intended to replace existing nomenclatural catalog databases, and it makes no assessment or judgment of the taxonomic content of any published work. ZooBank assigns unique registration identifiers in four information domains of relevance to the ICZN Code: nomenclatural acts (including new names and other acts that affect existing names), publications, authors, and type specimens. These identifiers are envisioned as pointers to authoritative information concerning zoological nomenclature and are expected to become integral to current and future efforts to index taxonomic content. The complete implementation details of the ZooBank registry are currently being discussed, developed, and tested, with involvement from ICZN Commissioners, nomenclatural data managers and the taxonomic community at large. Many questions concerning technical implementation details, content sourcing and prioritization, information quality standards, and scenarios for mandatory registration are open to discussion. As much as there is an urgent need to answer these questions soon, there is also the need to “get it right”, ensuring a solid foundation for the next 250 years of zoological taxonomy."

In: Systema Naturae 250 – A quarter millennium of zoological nomenclature, Ed. Polaszek, Taylor & Francis, London., 2010

ZooTaxa, 2008

Nomenclature represents the backbone upon which virtually all biological information is organized... more Nomenclature represents the backbone upon which virtually all biological information is organized. However, the prac- tice of zoological nomenclature has changed relatively little since its start in 1758. As modern technology changes the paradigm under which modern scientists exchange information, there is increasing need to capitalize on these same tech- nologies to fortify nomenclature. ZooBank has been proposed as the official registry of names and nomenclatural acts, in zoology, as well as associated published works and their authors, and type specimens. Having a coordinated registry of zoological names, integrated with the existing Code of Zoological Nomenclature, will allow increased efficiency of com- munication among biologists, and enhanced stability of names. Such a registry would encompass two distinct realms, each with their own set of challenges. Retrospective registration involves the monumental task of aggregating and vali- dating two and a half centuries of existing names, whereas prospective registration must be tightly integrated with the future paradigm in which scientific names are created and managed under new models of publication. The prototype of ZooBank has been hosted at Bishop Museum during its initial development phase. Following the lead of standard-setting bodies in biodiversity informatics, Life Science Identifiers (LSIDs) have been selected for use as the globally unique identifiers for ZooBank registration entries. The first ZooBank LSIDs were issued on January 1st, 2008, and included five new fish species described in a work published that same day, as well as all 4,819 names established in the 10th Edition of Linnaeus’ Systema Naturae. Three alternate scenarios for implementing mandatory registration in ZooBank have been articulated, each incorporating different degrees of coordination between published works and registration events. A robust discussion involving a broad spectrum of practicing zoological taxonomists is required over the next several years to define the specific implementation aspects of ZooBank.

Report to Royal Geographical Society & National Geographic Society, 2005

The Malagarasi drainage in western Tanzania is among the world's most important wetland regions. ... more The Malagarasi drainage in western Tanzania is among the world's most important wetland regions. The area contains biodiversity of regional and international significance but until this expedition its biological and physical characteristics had received almost no scientific attention. Our primary aims were to survey each of the primary biotopes of the Malagarasi Basin to provide baseline quantitative data on 1) aquatic biodiversity and 2) limnological functioning. The scientific data we generated is an important first contribution to understanding this imperiled ecosystem. Contacts with regional policy makers, some established during the expedition, will also help facilitate dissemination and utilization of our survey results for informing on conservation priorities in the region. Accomplishments: We sampled approximately 40 sites along the main flow of the Malagarasi River proper, and additionally associated shallow Lakes Sagara & Nyamagoma, small stream and delta inflows into Lake Tanganyika, other Malagarasi tributary rivers such as the Lugufu, Ruchugi, Ugalla, Makere and Igombe. Biodiversity collections focused on fish, herps (amphibians & reptiles) and molluscs, with additional collections of aquatic insects, crustaceans and diatoms – new species were found among most groups. Limnological sampling included physical parameters, water chemistry and productivity analyses indicating anthropogenic impacts throughout the region. Our aquatic surveys of the remote Igamba Falls area are apparently the first of their kind and revealed a number of new fish and mollusc species, making this site not only of special interest, but also of special concern as it is under discussion for hydropower installation. Our aerial photographic survey was the first for the river drainage and provides detailed information on habitat use in the areas surveyed.

Shells and Bridges (Public discussion, Arup, London, March 2011) In March 2011 a cross-discipl... more Shells and Bridges (Public discussion, Arup, London, March 2011)

In March 2011 a cross-disciplinary public discussion Shells and Bridges was held at Arup, London, to coincide with the exhibition Bridge Stories, which ran in Phase 2 (arup.com/phase2) from 22 Oct 2010 to 18 March 2011. Taking part were architect Mike Tonkin of Tonkin Liu, engineer Ed Clark of Arup, evolutionary biologist and molluscan researcher Ellinor Michel of the Natural History Museum, London, and bridge engineer Angus Low of Arup. Together they explored the geometry and nature of shells and bridges and their potential connections.

Friends of Crystal Palace Dinosaurs has simple aims: promote long-term conservation of the d... more Friends of Crystal Palace Dinosaurs has simple aims:
promote long-term conservation of the dinosaurs and raise funds in support of this aim
encourage research, interpretation, engagement, and access related to the dinosaurs
work with other stakeholders towards broader aims in Crystal Palace Park

The term “dinosaurs” refers to the sum total of the approximately thirty paleontological statues, five geological displays, and related landscaping in the vicinity of the tidal lake in Crystal Palace Park.

What’s our strategy?
Our 2013-14 strategy is straightforward:
lobby Bromley Council and English Heritage to commission a proper survey of the conservation needs
fundraise to support this work
make sure the conservation work is done, done properly, and completed to a high standard
continue to fundraise to support long-term conservation

At the same time, we are working on plans for research and interpretation. We continue to raise issues related to access and visitor support. We also are discussing ways to expand engagement, such as through online resources and community activity.

Who are we?
Friends of Crystal Palace Dinosaurs is a group of local residents who have regular contact with the park and the dinosaurs. We see firsthand, with our own eyes, the state of the dinosaurs and their surroundings.
We are volunteers. Feel free to get in touch if you would like to help and if you have skills that you think we could benefit from.

Governance
Friends of Crystal Palace Dinosaurs (“Friends”) came together in 2013. We are working towards a formal organisation as a charity.

Geological Society of America Abstracts with Programs, 2017

FIGURE 3. Components of an LSID. There does not appear to be a consistent implementation of the v... more FIGURE 3. Components of an LSID. There does not appear to be a consistent implementation of the version part of the LSID, and it is not incorporated into ZooBank LSIDs.

FIGURE 1. Diagrammatic representation of different nomenclatural interpretations for species A th... more FIGURE 1. Diagrammatic representation of different nomenclatural interpretations for species A through I, mapped to a hypothesized phylogeny. Taxonomist 1 recognizes three new genus names; the genus Aus is typified by species A; Cus by species C, and Eus is by species E. Taxonomist 2 treats them as congeners (the diagram assumes that Aus has nomenclatural priority over Cus, and Cus over Eus). Taxonomist 3 recognizes two genera. Taxonomist 4 believes the underlying phylogeny is incorrect, and interprets the breakdown of two genera differently. Typification is necessary to establish which cluster each genus name is associated with, when taxonomic definitions of genera change.

Lake Tanganyika’s many endemic species are under threat by impacts from human development and lan... more Lake Tanganyika’s many endemic species are under threat by impacts from human development and land use changes. Anthropogenic sediment inputs into the lake have increased, with a suite of negative effects on the benthic fauna. Sedimentation reduces habitat heterogeneity, alters cycling of nutrients, interferes with visibility, and interferes with photosynthesis. For fauna of the rocky benthos, settled sediments may directly affect movement, digestion, and respiration. Experimental tests and field studies are needed to determine the species most at risk and the effects most damaging from excess sedimentation.

Aim Current estimates of species richness within rapidly evolving species flocks are often highly... more Aim Current estimates of species richness within rapidly evolving species flocks are often highly dependent on the species status of allopatric populations that differ in phenotypic traits. These traits may be unreliable indicators of biological species status and systematists may have inconsistently assigned species among lineages or locations on the basis of these traits, thus hampering comparative studies of regional species richness and speciation rates. Our aim was to develop a method of generating standardized estimates of regional species richness suitable for comparative analysis, and to use these estimates to examine the extent and consistency of species assignment of allopatric populations within rapidly evolving cichlid fish flocks present in three east African lakes. Location Lakes Malawi, Victoria and Tanganyika. Methods Using published taxon co-occurrence data, a novel approach was employed to calculate standardized 'minimum' estimates of regional species richness for hard substrate associated complexes of cichlids within each of the lakes. Minimum estimates were based on an explicit assumption that if taxa present on equivalent habitats have disjunct distributions, then they are allopatric forms of the same species. These estimates were compared with current observed 'high-end' regional species richness estimates for those complexes to determine the consistency of species assignment of allopatric populations between lineages within a lake. A 'sympatry' index was developed to enable comparisons of levels of species assignment of allopatric populations between-lakes to be made. Results Within each lake, the minimum and high-end estimates for species richness were significantly correlated across complexes, indicating that the complexes that contain more recognized species contain the most genuine biological species. However, comparisons of complexes among lakes revealed considerable differences. For equivalent geographical areas, substantially higher proportions of recognized species were totally allopatric within the studied Lake Malawi and Lake Victoria complexes, than those of Lake Tanganyika.

Bulletin of Zoological Nomenclature, 2011

Figure 6. Plots of length against PC1 for all eight species of Lavigeria studied with regressed l... more Figure 6. Plots of length against PC1 for all eight species of Lavigeria studied with regressed lines and R2 values. Length values are log transformed.

PALAIOS, 2020

ABSTRACTThe lake bottom along structural platforms in Lake Tanganyika, Africa, is carpeted with n... more ABSTRACTThe lake bottom along structural platforms in Lake Tanganyika, Africa, is carpeted with numerous large shell beds, known to be of late Holocene age, but of uncertain assemblage process. The shell beds may be the result of sedimentological (physical) assembly processes, or biological processes, or both. Previous work focused on the distribution of shell-rich facies, and showed time averaging of the surficial shell bioclasts over the last ∼ 1600 calendar years BP. We focus on an extensive shell deposit along a deltaic platform in Kungwe Bay, Tanzania and examine time-averaging and taphonomy of Neothauma tanganyicense shells to constrain sedimentological and biological processes forming concentrations of shells. New radiocarbon dating indicates that Neothauma shells are time-averaged over the last ∼ 3000 calendar years. Younger shells predominate shallow-water and exhibit unimodal age distributions, while shells from deeper-water exhibit a broader age distribution. Taphonomic r...

The purpose of this paper is to suggest reinstating the wording of the third edition of the Code ... more The purpose of this paper is to suggest reinstating the wording of the third edition of the Code for Recommendation 72A: ‘The term ‘allotype’ may be used to 260 Bulletin of Zoological Nomenclature 65(4) December 2008

Sediment erosion from land and transport and deposition on littoral habitats has been identified ... more Sediment erosion from land and transport and deposition on littoral habitats has been identified as a form of pollution threatening the biodiversity of Lake Tanganyika (Cohen et al., 1993, 1996; Alin et al. 1999; Donoghue & Irvine, 2003; McIntrye et al. submitted). This anthropogenic sediment can alter the native aquatic habitat by blocking light when it is in suspension, affecting water chemistry and changing the substrate where it is deposited. Effects are most severe in rocky habitats, which in their pristine states have specialized endemic faunas and floras that are tightly co-evolved to clear water physical surroundings. Allochthonous sediment in suspension decreases light quantity and quality, reducing algal growth and potentially changing algal composition. When sediments settle out of the water onto the rock surface, the particles may interfere directly with algal growth and also survivorship of the fauna that lives on the algae. Sediment may coat the rock surfaces interferi...

Compared to collections kept safe inside museums, outdoor sculpture is affected by additional ris... more Compared to collections kept safe inside museums, outdoor sculpture is affected by additional risk factors. Sculpture in the public realm is exposed to the elements, pollution and direct sunshine. It is more vulnerable to vandalism and the proximity to nature can also take its toll. At the same time, the condition of outdoor sculpture is often not monitored as rigorously as that of museum collections. However, damage doesn’t go unnoticed by the public and, channelled in the right way, the public’s critical eye can be turned to positive pressure, increasing support for conservation work and helping to improve conditions for the displays.

The recent description of the fossil primate Darwinius masillae in the online journal PLoS ONE ex... more The recent description of the fossil primate Darwinius masillae in the online journal PLoS ONE exemplifies an increasingly common problem: nomenclatural acts in non-print venues that are not considered 'published' under the Code's Articles 8.6 and 9.8. Although the name Darwinius was subsequently validated by the publication of hardcopy offprints of the electronic paper, other zoological names have been published electronically in this and other online journals, and the broader taxonomic community's acceptance of these invalidly published names suggests that it is the Code itself that is outdated in refusing to recognise names accepted by everyone else. If the Code is not quickly changed to accommodate electronic publication, it will become marginalised and ignored, to the detriment of sense and stability in nomenclature. The increasing prevalence of electronic publishing leaves only a small window of opportunity in which the Code can act to regulate nomenclatural ac...

This document is the final published abstract of a conference presentation, details available on ... more This document is the final published abstract of a conference presentation, details available on the conference website http://www.sial-online.org/conferences/sial8.

Advances in Ecological Research, 2000

... One such example is included in this analysis; L. coronata had not been recorded from the lak... more ... One such example is included in this analysis; L. coronata had not been recorded from the lake since 1985, until a thriving, although geographically limited, population was discovered in Kigoma in 1998 (Michel, pers. obs.). ... guillemei is tall-spired, while Nov. gen. n. sp. is squat. ...

Lake Tanganyika, East Africa, is renowned for its high species diversity and numerous endemic rad... more Lake Tanganyika, East Africa, is renowned for its high species diversity and numerous endemic radiations. One of these, a ‘superflock’ of benthic gastropods is the most diverse (>100 spp.) and disparate (18 genera) extant radiation of its kind[1]. Despite this it remains poorly systematised. One component, the iconic genus Paramelania, has been known for 130 years and historically thought to comprise 2-5 morphologically variable species (and occasionally ‘forms’; Figure 1) [2,3]; however, it has long been recog-nised that the genus likely contains greater diversity and is in need of revision[3]. Previous phylogenetic analyses revealed five ro-bust clades congruent with a priori fine-scale shell-based species[4]. We used this correspondence to assess species diversity in three major historic collections comprising shells only, including samples from the currently inaccessible Congo coast. Re-assessments of two modern research collections, largely from the Tanzanian coast, were also conducted in the light of insights gained from his-toric samples. Opercula and radulae were examined for all putative taxa for which material was available.

Trends in ecology & evolution, 2011

In the otherwise excellent special issue of Trends in Ecology and Evolution on long-term ecologic... more In the otherwise excellent special issue of Trends in Ecology and Evolution on long-term ecological research (TREE 25(10), 2010), none of the contributors mentioned the importance of natural history collections (NHCs) as sources of data that can strongly complement past and ongoing survey data. Whereas very few field surveys have operated for more than a few decades, NHCs, conserved in museums and other institutions, comprise samples of the Earth's biota typically extending back well into the nineteenth century and, in some cases, before this time. They therefore span the period of accelerated anthropogenic habitat destruction, climate warming and ocean acidification, in many cases reflecting baseline conditions before the major impact of these factors.