Gyrolithes scintillus Laing, Buatois, Mángano, Narbonne et Gougeon, 2018

Diagnosis: Unlined, smooth, wide-form, variably coiled Gyrolithes. Low burrow radius to whorl radius ratio i.e. wide-form (κ= 0.1–0.4; avg. 0.3), variable height between whorls to burrow width ratio i.e. variably coiled (δ= 1.5–5.83; avg. 3.58), and low height between whorls to whorl circumference ratio i.e. shallow whorl incline (β= 0.2–0.6; avg. 0.3).

Description: Unbranched, passively in filled, circular helical burrows, oriented vertical to oblique to the bedding plane, consisting of coils which are not in contact. Burrows are circular in cross-section, with radii (r) ranging from 0.25–1 mm, with an average of 0.51 mm. Whorl radius (R) was measured from the middle of the burrow, and is 0.70–4.65 mm with an average of 2.10 mm. Height between whorls (h) ranged from 1.4 –8 mm, with an average height of 3.69 mm. Complete specimens show up to 7 whorls, with an average of 3 whorls. This average is likely biased towards smaller values, as several top whorls were possibly truncated by erosion. Two specimens (Fig. 5B) have elongated bottom compartments, extending from the bottommost helix. Burrow depth is 5–27.9 mm, with an average burrow depth of 10.44 mm. Assuming an originally circular burrow shape, the difference between burrow radius on the y- and x- axes can be equated to sedimentary compression, and was found to be 30%.