Giles Miller | Natural History Museum, London (original) (raw)

Papers by Giles Miller

Journal of Micropalaeontology, Dec 1, 2000

Journal of Micropalaeontology, May 1, 2005

Journal of Micropalaeontology, Dec 1, 1993

Ocean-floor sediment samples collected up to 150 years ago represent an important historical arch... more Ocean-floor sediment samples collected up to 150 years ago represent an important historical archive to benchmark global changes in the seafloor environment, such as species' range shifts and pollution trends. Such benchmarking requires that the historical sediment samples represent the state of the environment at-or shortly before the time of collection. However, early oceanographic expeditions sampled the ocean floor using devices like the sounding tube or a dredge, which potentially disturb the sediment surface and recover a mix of Holocene (surface) and deeper, Pleistocene sediments. Here we use climate-sensitive microfossils as a fast biometric method to assess if historical seafloor samples contain a mixture of modern and glacial sediments. Our assessment is based on comparing the composition of planktonic foraminifera (PF) assemblages in historical samples with Holocene and Last Glacial Maximum (LGM) global reference datasets. We show that eight out of the nine historical samples contain PF assemblages more similar to the Holocene than to the LGM PF assemblages, but the comparisons are only significant when there is a high local species' temporal turnover (from the LGM to the Holocene). When analysing temporal turnover globally, we show that upwelling and temperate regions had greatest species turnover, which are areas where our methodology would be most diagnostic. Our results suggest that sediment samples from historical collections can provide a baseline of the state of marine ecosystems in the late nineteenth century, and thus be used to assess ocean global change trends.\r\n\r\n## Related materials:\r\nRillo MC, Kucera M, Ezard THG and Miller CG (2019) Surface Sediment Samples From Early Age of Seafloor Exploration Can Provide a Late 19th Century Baseline of the Marine Environment. Front. Mar. Sci. 5:517. doi: https://doi.org/10.3389/fmars.2018.00517\r\n\r\nMarina Costa Rillo (2016). Dataset: Henry Buckley Collection of Planktonic Foraminifera. Natural History Museum Data Portal (data.nhm.ac.uk). htt [...]

Science Advances

The outer layer of the pollen grain, the exine, plays a key role in the survival of terrestrial p... more The outer layer of the pollen grain, the exine, plays a key role in the survival of terrestrial plant life. However, the exine structure in different groups of plants remains enigmatic. Here, modern and fossil coniferous bisaccate pollen were examined to investigate the detailed three-dimensional structure and properties of the pollen wall. X-ray nanotomography and volume electron microscopy are used to provide high-resolution imagery, revealing a solid nanofoam structure. Atomic force microscopy measurements were used to compare the pollen wall with other natural and synthetic foams and to demonstrate that the mechanical properties of the wall in this type of pollen are retained for millions of years in fossil specimens. The microscopic structure of this robust biological material has potential applications in materials sciences and also contributes to our understanding of the evolutionary success of conifers and other plants over geological time.

Proceedings of the Geologists' Association, Jun 1, 2023

This is a reconstructed 3D image of a modern pine pollen grain, enabling to visualize the fine st... more This is a reconstructed 3D image of a modern pine pollen grain, enabling to visualize the fine structure and density variations within the specimen. The voxel size is isotropic 40 nm, and the image size is 1900 x 1400 x 1260 voxels, stored in a simple raw format, 8 bit unsigned integers. The data was collected during experiment EV-314 at the beamline ID16A-NI.

Biology Letters, 2021

The fossil record of terrestrialization documents notable shifts in the environmental and physiol... more The fossil record of terrestrialization documents notable shifts in the environmental and physiological tolerances of many animal and plant groups. However, for certain significant components of modern freshwater and terrestrial environments, the transition out of marine settings remains largely unconstrained. Ostracod crustaceans occupy an exceptional range of modern aquatic environments and are invaluable palaeoenvironmental indicators in the fossil record. However, pre-Carboniferous records of supposed non-marine and marginal marine ostracods are sparse, and the timing of their marine to non-marine transition has proven elusive. Here, we reassess the early environmental history of ostracods in light of new assemblages from the late Silurian of Vietnam. Two, low diversity but distinct ostracod assemblages are associated with estuarine deposits. This occurrence is consistent with previous incidental reports of ostracods occupying marginal and brackish settings through the late Silu...

Journal of the Geological Society, 2020

The Ludlow Bone Bed (Welsh Basin) is a critical stratigraphic horizon and contains a rich assembl... more The Ludlow Bone Bed (Welsh Basin) is a critical stratigraphic horizon and contains a rich assemblage of fish scales. Units above provide insights into the early evolution of animal and plant life. The bed has not yet been radioisotopically dated. Here, we report 207 secondary ion mass spectrometry (SIMS) ages from 102 zircon (ZrSiO4) grains from the Ludlow (n = 2) and stratigraphically higher Downton (n = 1) bone beds. SIMS ages are middle Ordovician (471.6 ± 20.7 Ma) to late Devonian (375.7 ± 14.6 Ma, 238U–206Pb, ±1σ analytical uncertainty). Cathodoluminescence images show that the youngest ages appear affected by alteration. Chemical abrasion isotope dilution thermal ionization mass spectrometry (CA-ID-TIMS) U–Pb geochronology was utilized to improve precision. Detrital zircon grains from Downton yield 424.91 ± 0.34/0.42/0.63 Ma and from Ludlow 424.85 ± 0.32/0.41/0.62 Ma (n = 5 each, 238U–206Pb, ±2σ analytical, tracer or systematic uncertainty). These ages provide a maximum deposi...

Paleoceanography and Paleoclimatology, 2019

Planktonic foraminiferal species identification is central to many paleoceanographic studies, fro... more Planktonic foraminiferal species identification is central to many paleoceanographic studies, from selecting species for geochemical research to elucidating the biotic dynamics of microfossil communities relevant to physical oceanographic processes and interconnected phenomena such as climate change. However, few resources exist to train students in the difficult task of discerning amongst closely related species, resulting in diverging taxonomic schools that differ in species concepts and boundaries. This problem is exacerbated by the limited number of taxonomic experts. Here we document our initial progress toward removing these confounding and/or rate-limiting factors by generating the first extensive image library of modern planktonic foraminifera, providing digital taxonomic training tools and resources, and automating species-level taxonomic identification of planktonic foraminifera via machine learning using convolution neural networks. Experts identified 34,640 images of modern (extant) planktonic foraminifera to the species level. These images are served as species exemplars through the online portal Endless Forams (endlessforams.org) and a taxonomic training portal hosted on the citizen science platform Zooniverse (zooniverse.org/projects/ahsiang/ endless-forams/). A supervised machine learning classifier was then trained with~27,000 images of these identified planktonic foraminifera. The best-performing model provided the correct species name for an image in the validation set 87.4% of the time and included the correct name in its top three guesses 97.7% of the time. Together, these resources provide a rigorous set of training tools in modern planktonic foraminiferal taxonomy and a means of rapidly generating assemblage data via machine learning in future studies for applications such as paleotemperature reconstruction.

Journal of Micropalaeontology, 2018

Planktonic foraminifera are widely used in biostratigraphic, palaeoceanographic and evolutionary ... more Planktonic foraminifera are widely used in biostratigraphic, palaeoceanographic and evolutionary studies, but the strength of many study conclusions could be weakened if taxonomic identifications are not reproducible by different workers. In this study, to assess the relative importance of a range of possible reasons for among-worker disagreement in identification, 100 specimens of 26 species of macroperforate planktonic foraminifera were selected from a core-top site in the subtropical Pacific Ocean. Twenty-three scientists at different career stages-including some with only a few days experience of planktonic foraminifera-were asked to identify each specimen to species level, and to indicate their confidence in each identification. The participants were provided with a species list and had access to additional reference materials. We use generalised linear mixed-effects models to test the relevance of three sets of factors in identification accuracy: participant-level characteristics (including experience), species-level characteristics (including a participant's knowledge of the species) and specimen-level characteristics (size, confidence in identification). The 19 less experienced scientists achieve a median accuracy of 57 %, which rises to 75 % for specimens they are confident in. For the 4 most experienced participants, overall accuracy is 79 %, rising to 93 % when they are confident. To obtain maximum comparability and ease of analysis, everyone used a standard microscope with only 35× magnification, and each specimen was studied in isolation. Consequently, these data provide a lower limit for an estimate of consistency. Importantly, participants could largely predict whether their identifications were correct or incorrect: their own assessments of specimen-level confidence and of their previous knowledge of species concepts were the strongest predictors of accuracy.

Geological Magazine, 2018

The Middle Shale Member of the Amdeh Formation is interpreted to be of Early Ordovician age based... more The Middle Shale Member of the Amdeh Formation is interpreted to be of Early Ordovician age based on its trace fossils, stratigraphic context and a newly discovered fauna of conodonts. The member abruptly overlies the Lower Quartzite Member, which may be Early Cambrian, and passes gradationally-upward into the Upper Quartzite Member, which is probably Early–Middle Ordovician. The 542.5 m thick Middle Shale Member can be divided into two parts: a shaly lower part, and a sandy upper part that contains an influx of heavy minerals. Bioturbation by marine trace fossils is one of the most obvious characteristics of the member. The shales and sandstones are interpreted to be ofCruzianaandSkolithosichnofacies and represent shallow-marine shelf, shoreface, beach and coastal deposits. Sparse shelly fossils occur in the sandy upper part, principally bivalves, inarticulate brachiopods, ostracods and conodonts. The small assemblage of conodonts includes elements interpreted to be Tremadocian (Te...

Geological Magazine, 2016

The Amdeh Formation is a 3.4 km stack of sparsely fossiliferous quartzites and shales which crops... more The Amdeh Formation is a 3.4 km stack of sparsely fossiliferous quartzites and shales which crops out in the Al Hajar mountains near Muscat. Here we describe the uppermost member (Am5) that can be dated biostratigraphically as Darriwilian and which is the outcrop equivalent, and probably the seaward continuation, of the Saih Nihayda Formation in the Ghaba Salt Basin of northern Oman. The outcrops at Wadi Daiqa and Hayl al Quwasim consist of 690 m of quartzitic sandstones, shales and bivalve-rich shell beds. Trace fossils referable to theCruzianaandSkolithosichnofacies abound. The member comprises storm-dominated shelf, shoreface and delta deposits. A number of new discoveries have been made in the outcrops: fragments of the arandaspid fishSacabambaspis, ossicles and moulds of the early disparid crinoidIocrinus, two new genera of conodont, an occurrence of the rare trinucleid trilobiteYinpanolithus, and palynological and sedimentological evidence of more continuous Floian–Darriwilian...

Science, 2009

Giant ostracode sperm date back at least 100 million years ago.

Journal of Micropalaeontology, 2004

A Q-Switched Nd: YAG (neodymium yttrium aluminium garnet) infrared laser can be used to clean mic... more A Q-Switched Nd: YAG (neodymium yttrium aluminium garnet) infrared laser can be used to clean micropalaeontological specimens, particularly those coated in gold-palladium for SEM studies. Variable pressure SEM images taken of uncoated specimens before and after laser treatment show that the laser does not have a detrimental affect on micropalaeontological specimens composed of phosphate, silica or calcite in a number of wall structural forms. The laser has no effect on the textural surface of the specimen but flakes and crinkles water-soluble mounting glues used to fix specimens to the stub. Sticky carbon tabs (Reference Agar Scientific) were found to be the best mounting medium for holding specimens in place during treatment but microfossils were prone to become detached during the process if not attached firmly. Laser cleaning has a number of advantages over traditional methods of gold removal using sodium cyanide, which is toxic, slow and does not effectively remove gold-palladium coatings due to the insolubility of palladium in the reagent. This laser removal method has potential for removing matrix from specimens as well as other types of coating and mounting media including aluminium, carbon and wax. Safe removal of coatings releases important scientific information from gold-palladium coated museum micropalaeontological specimens.

Journal of Micropalaeontology, 2012

IntroductIon The bulk of the non-DSDP/ODP and-CRDP material was collected by RVD, with small quan... more IntroductIon The bulk of the non-DSDP/ODP and-CRDP material was collected by RVD, with small quantities donated by colleagues and co-workers. Most of it has been described in a series of publications, and the slides are arranged in sets that relate to particular articles. The remainder is classified as 'undescribed', including suites from cores collected in 1992 from the oceanographic research vessels Professor Logachev and Benguela. Many of the specimens come from sediments collected from the University of Cape Town research vessel Thomas B Davie. The latter have a TBD prefix, and location sites and water depths are listed in the database/spreadsheet using a TBDXXXX notation. Samples with prefix AX were collected by Sea Fisheries Research Institute, Cape Town-their localities are also listed in the database/spreadsheet. The collection has 2337 slides in the main set, with a further 197 in the New Zealand/Antarctica subset, giving a grand total of 2534 slides containing ~94 000 specimens. The New Zealand/Antarctica subset has NHM PM-OS numbers 16596-16792, while the main collection has NHM PM-OS numbers 16988-19324. There are holotypes, paratypes, figured specimens, topotypes, an idiotype, and a large selection of comparative material. Many of the last category are single-species collections arranged in stratigraphical sequence (either from outcrop, or cores: 'stratigraphical selections'), as well as specimens from various water depths. The collection is listed on a spreadsheet that can be sent on request. In summary, the main geographical/stratigraphical slide-sets are: SOUTH/SOUTHERN AFRICA Jurassic to Upper Cretaceous: south and southeast coasts (142 slides) Middle to Upper Cretaceous: east coast (185 slides) Cenozoic: onshore & offshore (296 slides) Quaternary: onshore & offshore, including non-marine faunas (1093 slides) ANTARCTICA/NEW ZEALAND Upper Cretaceous (197 slides) Cenozoic (119 slides) SOUTHERN OCEAN Middle to Upper Cretaceous (62 slides) Cenozoic (348 slides) Holocene (69 slides) SUNDRY MATERIAL Various ages (23 slides) Details of the main sets, showing slides referred to NHM OSxxxxx and informal (RVDxxxx) numbers on cabinet drawers, are listed below. South AfrIcA: JurASSIc to upper cretAceouS-South And SoutheASt coAStS Brenton, Knysna. upper Jurassic 9 slides: OS17011-17017 (RVD24-30); OS18404-18405 (RVD 1417-1418). Publication: Dingle & Klinger (1972). Faunal slides and topotypes. Figured and other type material is in the South African Museum, Cape Town. Samples collected by Dr H. C. Klinger in 1971. Age of outcrops still in dispute-probably late Jurassic; see Klinger et al. (1972).

Scientific Reports, 2020

Widely regarded as an imminent threat to our oceans, ocean acidification has been documented in a... more Widely regarded as an imminent threat to our oceans, ocean acidification has been documented in all oceanic basins. Projected changes in seawater chemistry will have catastrophic biotic effects due to ocean acidification hindering biogenic carbonate production, which will in turn lead to substantial changes in marine ecosystems. However, previous attempts to quantify the effect of acidification on planktonic calcifying organisms has relied on laboratory based studies with substantial methodological limitations. This has been overcome by comparing historic plankton tows from the seminal HMS Challenger Expedition (1872–1876) with the recent Tara Oceans expedition material (2009–2016). Nano CT-scans of selected equatorial Pacific Ocean planktonic foraminifera, have revealed that all modern specimens had up to 76% thinner shells than their historic counterparts. The “Challenger Revisited” project highlights the potential of historic ocean collections as a tool to investigate ocean acidi...

Cypridea (Sebastianites) fida Krömmelbei... more Cypridea (Sebastianites) fida Krömmelbein, 1962 Fig. 3, 10a–c 1962 Cypridea (Sebastianites) fida n. sp. —Krömmelbein, p. 460–462, pl. 57, fig. 31. Diagnosis: A Cypridea (Sebastianites) species with an almost horizontal, slightly saddled-in dorsal margin, consequently with a fairly high-lying posterior cardinal angle. From the valve middle the sulcus branches to the anterior, the antero-ventral, the postero-ventral and to the postero-dorsal. The areas of the valve which border the sulcus are thickened in an undulating way and with distinct pitted sculpture; all remaining valve areas without fine sculpture. Rostrum absent. Holotype: Carapace, SMF Xe 4203. Paratype: 1 carapace, SMF Xe 4204. Dimensions: Holotype, length 1.15mm, height 0.72mm.