Measurements of Silurian brachiopod specimens from the Pentland Hills, Scotland
Data files
Feb 09, 2024 version files 89.52 KB
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Dyrad_supplementary_material_-_measurements.xlsx
85.73 KB
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README.md
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Abstract
The abundant and diverse brachiopod fauna from the Silurian (upper Llandovery-lower Wenlock) rocks of the Pentland Hills is described within its geographical stratigraphical context. The majority of species are described in detail, discussed and illustrated. A total of 53 species attributable to the following superfamilies are present (numbers of species, including those in open nomenclature, in parentheses): Linguloidea (7), Craniopsoidea (1), Discinoidea (4), Strophomenoidea (9), Plectambonitoidea (2), Chonetoidea (1), Childiopsoidea (2), Skenidioidea (1), Dalmanelloidea (3), Pentameroidea (2), Rhynchonelloidea (4), Atrypoidea (4), Athyridoidea (5), Cyrtioidea (5) and Delthyridoidea (3). Five new species, Leptaena eska, Isorthis (Ovalella) clarksoni, Dicoelosia paratenua, Oglupes scotia and Lissatrypa scotica, are erected. Nevertheless in terms of abundance the fauna is dominated by individuals belonging to the Strophomenoidea, Plectambonitoidea and Dalmanelloidea. The composition of the fauna, its deeper-water setting associated with finer-grained siliciclastic substrates characterizes this Pentlandian biota.
README: Measurements of Silurian brachiopod specimens from the Pentland Hills, Scotland
https://doi.org/10.5061/dryad.8sf7m0cwd
Description of the data and file structure
The data are loosely structured in an Excel spreadsheet and and be cut and pasted if necessary.
Brachiopod measurements
Taxa, and the raw measurements taken from them, are listed here in alphabetical order. The number of ventral and dorsal valves measured is included. The measurement variates used (X1, X2, etc) are explained below. Specimen numbers are colour coded according to the formation in which they were located: red – Wether Law Linn Formation, purple – Cock Rig Formation, green – Deerhope Formation, blue – Reservoir Formation.
Measurements variates used in the present study, modified from Harper (1989). All measurements are in millimetres. Missing cells record missing data, due to incomplete specimens.
X1 sagittal length
X2 maximum width
X3 position of maximum width measured from posterior margin
X4 maximum depth measured perpendicular to sagittal length
X5 hinge width
X6 maximum length
X7 origin of fold or sulcus measured from posterior margin
X8 maximum width of rim or limbus
X9 maximum length of muscle scar measured from posterior sagittal margin
X10 maximum width of muscle scar
X11 wavelength of median rib at 2mm (or 5mm*) growth stage
X12 position of apex measured anteriorly from posterior margin
X13 length of base of spondylium
X14 maximum width of spondylium
X15 length of base of cruralium
X16 maximum width of cruralium
X17 anterior extension of brachiophore bases measured from umbo in plane of sagittal length
X18 transverse separation of ends of brachiophore bases (dorsal valve) or teeth (ventral valve)
X19 maximum depth of sulcus
X20 maximum width of sulcus/fold
X21 length of cardinal process base
X22 sagittal length of submedian septa
X23 transverse separation of anterior ends of submedian septa
X24 sagittal length of median septa
X25 angle of geniculation
X26 maximum width of visceral disc
X27 sagittal length of visceral disc
X28 number of rugae or growth lines
X29 maximum width of hingeline occupied by denticles
X30 sagittal length of bema measured from posterior margin
X31 maximum width of bema
X32 angle of divergence between lobes
X33 delthyrial angle
X34 angle of divergence of muscle scars
X35 number of denticles
X36 maximum length of spines
X37 number of capillae at anterior margin
X38 sagittal length of pedicle track
X39 maximum width of pedicle track
X40 sagittal length of midline
X41 number of ribs
X42 number of growth lamellae within 1mm of anterior margin
Variate calculated using 2mm growth stage except for the following taxa where the 5mm growth stage was used: *Erinostrophia undata (M’Coy, 1846), Eospirifer *cf. *radiatus (J. de C. Sowerby, 1834), Meristina?maclareni (Haswell, 1865), Pentlandella pentlandica (Haswell, 1865).
HARPER, D. A. T. 1989. Brachiopods from the Upper Ardmillan Succession (Ordovician) of the Girvan District, Scotland, Part 2. Monographs of the Palaeontographical Society, 79-128, pls. 12-22. doi.org/10.1080/25761900.2022.12131804
Sharing/Access information
The data are original measurements made on fossil specimens.
Methods
These are measurements made on fossil brachiopod internal and external moulds.