Papers by Robert Chandler
Proceedings of the Geologists' Association
A new section is described through the Ovale Bed in the Middle Inferior Oolite at the we-stern en... more A new section is described through the Ovale Bed in the Middle Inferior Oolite at the we-stern end of the outlier on Dundry Hill, south of Bristol. It provides new insights into the bio-stratigraphy of the ammonites of the Ovale Zone of the Lower Bajocian, still one of the least well-known parts of that Stage and of its succession of faunal horizons. The lower part of the bed is assigned to the horizon Bj-5, that of Witchellia romanoides (DOUVILLÉ). The upper part represents at least in part the former horizon Bj-6, that of ‘Sonninia ’ ovalis sensu BUCKMAN, which is in need of revision. Some of the more important ammonites are illustrated, including the lectotypes, here designated, of ‘Ludwigia ’ romanoides DOUVILLÉ and Witchellia sayni HAUG. A neotype is designated for Strigoceras compressum BUCKMAN, whose original type series came from the Ovale Zone of Dundry.
Proceedings of the Geologists' Association, 2016
Abstract Crustaceans occur within Thalassinoides burrow systems in the Upper Bajocian, Inferior O... more Abstract Crustaceans occur within Thalassinoides burrow systems in the Upper Bajocian, Inferior Oolite Formation of Oborne, Dorset. This is only the fourth record from the Jurassic worldwide, the first record from rocks between the Lower Jurassic, Toarcian and Upper Jurassic, Bathonian stages, and the third record from any rocks in the British Isles. The Sherborne Building Stone Beds of Frogden Quarry in Dorset were deposited over the very short time interval of only one ammonite faunal horizon, possibly as little as 30,000 years. This was probably due to flow of sediments into a forming graben. During this time there were episodes of slower sedimentation which allowed the formation of extensive Thalassinoides burrow systems at several horizons. From within, and outside, these burrows we have found remains of the macrurous crustacean Glyphea regleyana Desmarest. The evidence suggests that these were the burrow makers which were probably overwhelmed by sediment flows.
Geobios, 2013
A new exposure at Oborne, Dorset has yielded a rich fossil assemblage of the Lower Bajocian ammon... more A new exposure at Oborne, Dorset has yielded a rich fossil assemblage of the Lower Bajocian ammonite Kumatostephanus from the Laeviuscula and Humphriesianum zones. The principal bed containing this ammonite, the Green Grained White Marl is locally diachronous; it is an important local marker horizon and it is herein proposed as a formal stratigraphical unit. The specimens obtained allow a better understanding of the evolution of the genus Kumatostephanus and its relationships to the other stephanoceratids, notably Stemmatoceras.
A succession of 4 ammonite faunal horizons is described in detail from the Lower Bajocian (Ovale ... more A succession of 4 ammonite faunal horizons is described in detail from the Lower Bajocian (Ovale and Laeviuscula zones) of eastern Swabia. Their ammonite faunas are described and reviewed. A new classification is proposed of the Sonniniidae BUCKMAN, 1892 in which the
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright
Palaeodiversity, Nov 4, 2022
BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.
Palaeodiversity, Sep 23, 2022
BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen, 2020
Of the anomuran Eogastrodorus granulatus (Förster, 1985), the sole representative of the genus, o... more Of the anomuran Eogastrodorus granulatus (Förster, 1985), the sole representative of the genus, only the holotype from Bajocian strata in Switzerland was known until now. The five additional specimens described here have enabled us to supplement the morphological characterisation of both the genus and species. Of these five individuals, four originate from the shallow-marine Sherborne Limestone Member (Inferior Oolite Formation, lower upper Bajocian) in southern England. The fifth is from the shallow-marine biodetritic Audun-le-Tiche Limestone in Lorraine (France), of late early Bajocian ( Humphriesianum Zone) age; this is the stratigraphically oldest record of a gastrodorid known to date. Two juvenile carapaces from England are preserved within a piece of driftwood. We offer three possible interpretations for this occurrence; the hollowed out inside of the wood could have provided a place for moulting, retreating or mating. Alternatively, the two carapaces represent the remains of ...
Proceedings of the Geologists' Association, 2017
Members of the ammonite family Stephanoceratidae from the Middle Jurassic, Lower Bajocian, Laeviu... more Members of the ammonite family Stephanoceratidae from the Middle Jurassic, Lower Bajocian, Laeviuscula to Humphriesianum zones of South West England are revised. These comprise faunas resulting from periodic migrations and possibly hybridization. The taxonomic positions of Teloceras Mascke, 1907, Kumatostephanus Buckman, 1922, Gibbistephanus Buckman, 1928 and Pseudoteloceras Pavia and Fernández-López, 2016 are considered in the light of new research. A new subfamily Kumatostephaninae is erected and hypotheses are presented regarding the evolution of some Early Bajocian stephanoceratids. Pseudoteloceras digbyi sp. nov. represents the earliest 'Teloceras-like' morphology from the late Sauzei Zone. Refinement is made of the scheme of faunal horizons for the Lower Bajocian.
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen, 2014
Proceedings of the Geologists' Association, Jun 1, 2023
Dietze, V., Auer, W., Chandler, R.B., Neisser, E., Hummel, U., Wannenmacher, N., Dietl, G. & Schw... more Dietze, V., Auer, W., Chandler, R.B., Neisser, E., Hummel, U., Wannenmacher, N., Dietl, G. & Schweigert, G.: The Ovale Zone (Middle Jurassic, Early Bajocian) at its type locality near Achdorf (Wutach area, southwestern Germany) Fissilobiceras ovale (Quenstedt, 1886) is the index species of the Early Bajocian Ovale Zone as well as of the ovale horizon in the Jurassic of SW Germany. The variability of the species F. ovale in its type horizon (ovale horizon, in the lowermost part of the "Unterer Wedelsandstein") and type locality (Achdorf) is described. The Discites Zone is documented with a rich fauna of Hyperlioceras spp. and Sonninia spp. up to the base of the "Unterer Wedelsandstein", that represents the beginning of the ovale horizon. Sometimes specimens of Hyperlioceras co-occur with F. ovale in the same bed. However, the lithology of the Hyperlioceras specimens from the base of the "Unterer Wedelsandstein" Member is significantly different from the ...
The Lancet Oncology, 2019
Background Metastatic castration-resistant prostate cancer is enriched in DNA damage response (DD... more Background Metastatic castration-resistant prostate cancer is enriched in DNA damage response (DDR) gene aberrations. The TOPARP-B trial aims to prospectively validate the association between DDR gene aberrations and response to olaparib in metastatic castration-resistant prostate cancer. Methods In this open-label, investigator-initiated, randomised phase 2 trial following a selection (or pick-thewinner) design, we recruited participants from 17 UK hospitals. Men aged 18 years or older with progressing metastatic castration-resistant prostate cancer previously treated with one or two taxane chemotherapy regimens and with an Eastern Cooperative Oncology Group performance status of 2 or less had tumour biopsies tested with targeted sequencing. Patients with DDR gene aberrations were randomly assigned (1:1) by a computer-generated minimisation method, with balancing for circulating tumour cell count at screening, to receive 400 mg or 300 mg olaparib twice daily, given continuously in 4-week cycles until disease progression or unacceptable toxicity. Neither participants nor investigators were masked to dose allocation. The primary endpoint of confirmed response was defined as a composite of all patients presenting with any of the following outcomes: radiological objective response (as assessed by Response Evaluation Criteria in Solid Tumors 1.1), a decrease in prostate-specific antigen (PSA) of 50% or more (PSA50) from baseline, or conversion of circulating tumour cell count (from ≥5 cells per 7•5 mL blood at baseline to <5 cells per 7•5 mL blood). A confirmed response in a consecutive assessment after at least 4 weeks was required for each component. The primary analysis was done in the evaluable population. If at least 19 (43%) of 44 evaluable patients in a dose cohort responded, then the dose cohort would be considered successful. Safety was assessed in all patients who received at least one dose of olaparib. This trial is registered at ClinicalTrials.gov, NCT01682772. Recruitment for the trial has completed and follow-up is ongoing. Findings 711 patients consented for targeted screening between April 1, 2015, and Aug 30, 2018. 161 patients had DDR gene aberrations, 98 of whom were randomly assigned and treated (49 patients for each olaparib dose), with 92 evaluable for the primary endpoint (46 patients for each olaparib dose). Median follow-up was 24•8 months (IQR 16•7-35•9). Confirmed composite response was achieved in 25 (54•3%; 95% CI 39•0-69•1) of 46 evaluable patients in the 400 mg cohort, and 18 (39•1%; 25•1-54•6) of 46 evaluable patients in the 300 mg cohort. Radiological response was achieved in eight (24•2%; 11•1-42•3) of 33 evaluable patients in the 400 mg cohort and six (16•2%; 6•2-32•0) of 37 in the 300 mg cohort; PSA50 response was achieved in 17 (37•0%; 23•2-52•5) of 46 and 13 (30•2%; 17•2-46•1) of 43; and circulating tumour cell count conversion was achieved in 15 (53•6%; 33•9-72•5) of 28 and 13 (48•1%; 28•7-68•1) of 27. The most common grade 3-4 adverse event in both cohorts was anaemia (15 [31%] of 49 patients in the 300 mg cohort and 18 [37%] of 49 in the 400 mg cohort). 19 serious adverse reactions were reported in 13 patients. One death possibly related to treatment (myocardial infarction) occurred after 11 days of treatment in the 300 mg cohort. Interpretation Olaparib has antitumour activity against metastatic castration-resistant prostate cancer with DDR gene aberrations, supporting the implementation of genomic stratification of metastatic castration-resistant prostate cancer in clinical practice.
European Oncology & Haematology, 2018
The advent of enhanced imaging in prostate cancer has resulted in recurrent disease being identif... more The advent of enhanced imaging in prostate cancer has resulted in recurrent disease being identified earlier. This has led to an increase in the number of patients undergoing intervention at this early stage. There remains, however, a paucity of level one evidence to advise on the optimal management of this heterogenous group, with a significant number of patients experiencing biochemical relapse unlikely to die of metastatic prostate cancer. More work is needed to define those who do and do not require intervention, to avoid doing harm to an often elderly population.
European urology, Jan 16, 2018
Platinum-based regimens have not been proved to increase survival from advanced prostate cancer (... more Platinum-based regimens have not been proved to increase survival from advanced prostate cancer (PCa). Incontrovertible evidence that a proportion of prostate cancers have homologous recombination DNA (HRD) repair defects, and that such genomic aberrations are synthetically lethal with both poly(ADP)-ribose polymerase inhibition and platinum, has increased interest in the utilisation of these drugs against a subset of these diseases. Here in we report three patients with advanced castration-resistant PCa with HRD defects having exceptional responses to carboplatin.
Data Revues 00166995 V45i1 S001669951100091x, Jan 3, 2012
We present a modern revision of the dimorphic ammonite pair Strigoceras QUENSTEDT, 1886/Cadomocer... more We present a modern revision of the dimorphic ammonite pair Strigoceras QUENSTEDT, 1886/Cadomoceras MUNIER-CHALMAS, 1892 from the Middle Jurassic. The stratigraphically oldest hitherto known chronospecies of Strigoceras, S. praenuntium (BUCKMAN) appears in the Middle Aalenian as an extreme rarity. Records of the microconch genus Cadomoceras re- main unknown from strata older than Early Bajocian, but otherwise its stratigraphical range corresponds well with that of the macroconchs. The genus probably became extinct in the Early Bathonian (Zigzag Zone). The youngest known Strigoceras is S. callomoni n. sp. descri- bed here from the Macrescens Subzone of the Early Bathonian. Another new strigoceratid species, Granulochetoceras oppeliisculptum n. sp., is recorded by a single specimen from the early Garantiana Zone of eastern Spain, representing an interesting phyletic link between Stri- goceras QUENSTEDT, 1886 and Granulochetoceras GEYER, 1960. We include a brief review of the latter ge...
A succession of 4 ammonite faunal horizons is described in detail from the Lower Bajocian (Ovale ... more A succession of 4 ammonite faunal horizons is described in detail from the Lower Bajocian (Ovale and Laeviuscula zones) of eastern Swabia. Their ammonite faunas are described and reviewed. A new classification is proposed of the Sonniniidae BUCKMAN, 1892 in which the genera Sonninia BAYLE, 1879, Shirbuirnia BUCKMAN, 1910, Witchellia BUCKMAN, 1889, and Pseudoshirbuirnia n. gen. are regarded as independent phyletic strands. Fissilobiceras BUCK- MAN, 1919 is assigned to Hammatoceratidae BUCKMAN, 1887. A new genus, Pseudoshirbuir- nia (type species Amaltheus? stephani BUCKMAN, 1883) with a new species, Pseudoshirbuirnia oechslei n. sp. (= Sonninia tessoniana tessoniana (D'ORBIGNY) in OECHSLE) are erected. To sta- bilize the use of species names lectotypes are formally designated for Witchellia jugifera (WAAGEN), Shirbuirnia gingensis (WAAGEN), Sonninia (Euhoploceras) adicra (WAAGEN), and S. (Eu.) costosa (QUENSTEDT). The type horizons of some important ammonite taxa intro- duced by ...
Geobios, 2014
A biostratigraphical and systematic revision of the genera Labyrinthoceras and Frogdenites is pre... more A biostratigraphical and systematic revision of the genera Labyrinthoceras and Frogdenites is presented, based mostly on new specimens from the Lower Bajocian of the Betic Cordillera (southern Spain). Types and other supporting specimens are described, including some from southwestern England with precise biostratigraphy. Frogdenites is shown to span the Lower Bajocian (Ovale Zone to lowermost part of the Propinquans Zone), whereas Labyrinthoceras ranges from the Laeviuscula Zone (Trigonalis Subzone) to the Propinquans Zone. Both genera show well-marked dimorphism; the microconchs may have reduced lateral lappets. Labyrinthoceras meniscum (Waagen) [M] & [m] = Manselites mansellii (J. Buckman) is described along with specimens that are placed in the new species Labyrinthoceras dietzei nov. sp. [M]. Frogdenites is grouped into three morphospecies: Frogdenites fernandezlopezi nov. sp. [M] & [m?], an evolute morph with poorly developed tubercles; F. spiniger Buckman [M] & [m], which is more involute with strongly forward curving projecting ribs; and F. extensus (Buckman) [M] & [m] with a more eccentric coiling. Docidoceras tolleyi nov. sp., that possesses a morphology intermediate between Docidoceras and Frogdenites, is described. Phylogenetic analysis shows that the Sphaeroceratidae originated in the earliest Bajocian (Ovale Zone) and that Frogdenites is the oldest genus of Accepted finalized MS A c c e p t e d M a n u s c r i p t 2 this lineage. Docidoceras rather than Emileia may be the ancestor of the Sphaeroceratidae. The evolutionary path from Frogdenites to Labyrinthoceras, with "Chondroceras obornensis" Parsons, 1980 (unpubl. manuscript) as an intermediate step, involves size increase and disappearance of tubercles.
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Papers by Robert Chandler