Data from: Absolute axial growth and trunk segmentation in the early Cambrian trilobite Oryctocarella duyunensis
Data files
Dec 15, 2020 version files 222.07 KB
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Dataset_1.xlsx
41.57 KB
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Dataset_2.xlsx
33.95 KB
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Dataset_3.xlsx
144.23 KB
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README.txt
2.32 KB
Jul 29, 2021 version files 1.14 MB
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Dai_et_al_Supplementary_material.pdf
919.10 KB
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Dataset_1.xlsx
41.57 KB
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Dataset_2.xlsx
33.95 KB
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Dataset_3.xlsx
144.23 KB
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README.txt
2.32 KB
Abstract
A short stratigraphic interval near Bulin in western Hunan (China) yields multiple specimens of the ~514 Ma old oryctocarine trilobite Oryctocarella duyunensis. Size data obtained from these specimens indicates that, from meraspid degree 1 onwards, degrees represent successive instars. Meraspid growth persisted until a terminal stage was reached, providing the first example of determinate growth in trilobites and, notably, in an early Cambrian species. The sample contains three varieties of such terminal stages, recognized as holaspids, with 9, 10, or 11 thoracic segments respectively. During the meraspid phase growth rates were not constant in this species. The pattern of growth seen in the Bulin assemblage differs modestly from that reported in the same species from two other localities, attesting to microevolutionary variation in developmental patterns among these collections.
Data from:
Dai T., Hughes N.C., Zhang X.-L, Fusco G. (2021). Absolute axial growth and trunk segmentation in the early Cambrian trilobite Oryctocarella duyunensis. Paleobiology.
[Dataset 1 and 2 have also been used in Dai et al.(2021). Development of the early Cambrian oryctocephalid trilobite Oryctocarella duyunensis from western Hunan, China. Journal of Paleontology.]
DATASET 1
Dataset 1 comprises 968 specimens that permitted measurement of their sagittal dorsal length and the number of thoracic segments
Legend of dataset 1
NTH Number of THoracic segments
BL Body Length (in millimeters)
lnBL Natural logarithm of Body Length
DATASET 2
Dataset 2 is a subset of dataset 1 which comprises 643 specimens where, in addition, segment number in the pygidia could also be counted with confidence
Legend of dataset 2
NTH Number of THoracic segments
NPY Number of PYgidial segments
BL Body Length (in millimeters)
lnBL Natural logarithm of Body Length
DATASET 3
Dataset 3 is a subset of dataset 2 which comprises 337 specimens in which landmark-based measurements could be taken for an array of characters
Legend of dataset 3
Stage Developmental stage (instar) assignment based on the number of thoracic segments (see text)
morph Morph description based on the number of thoracic segments (first figure) and the number of pygidial segments (second figure)
NTH Number of THoracic segments
NPY Number of PYgidial segments
CCS Cephalic Centroid Size
CEL CEphalic Length
TRL TRunk Length
PYL PYgidial Length
PCj Distance of the Posterior boundary of Cephalic segment j from cephalon anterior boundary (PC0= frontal piece; PC6=CEL) [corresponds to the cumulative segment length of the cephalon until cephalic segment j included]
PTi Distance of the Posterior boundary of Trunk Segment i from cephalon/trunk boundary [corresponds to the cumulative segment length of the trunk until trunk segment i included]
All measures are in millimeters
Colors refer to segmental units of different body parts:
Olive green Frontal piece
Green Cephalon to the exclusion of the frontal piece
Dark blue Thorax
Blue Pygidium to the exclusion of the terminal piece
Purple Terminal piece
Note that in Fig. 1 junctions within the thorax are shown by pink diamonds, and those within the pygidium, and its posterior, in orange.