Radulopora Voigt, 1968

Taylor, Paul D., Martha, Silviu O. & Gordon, Dennis P., 2018, Synopsis of ‘ onychocellid’ cheilostome bryozoan genera, Journal of Natural History (J. Nat. Hist.) 52 (25 - 26), pp. 1657-1721 : 1694-1695

Genus Radulopora Voigt, 1968

( Figure 23 )

Type species

Biflustra radula Marsson, 1887 , by original designation. Cretaceous, early Maastrichtian, Rügen, Mecklenburg-Vorpommern, Germany .

Diagnosis

Colony erect, bifoliate, palmate ( Figure 23 (a), dichotomously branched ( Figure 23 (b));?basally articulated. Autozooids elongate subhexagonal to pyriform; zooidal boundaries grooved. Cryptocyst extensive, granular proximally, smooth and steeply sloping distally with a pair of pits ( Figure 23 (d)). Gymnocyst lacking. Opesia, occupying about half of frontal surface; inverted egg shaped, longer than wide, lacking opesiular indentations and lateral constrictions. Closure plates sunken, some containing a foramen and with a pair of indentations of the opercular sclerites ( Figure 23 (b)). Ovicells immersed, the distal border of ovicellate zooids formed by the proximal cryptocyst of the next zooid in series ( Figure 23 (e)). Avicularia interzooidal ( Figure 23 (f)), small, located distally of each autozooid, directed proximolaterally; opesia longitudinally elliptical.

Remarks

Voigt (1968, fig. 2) depicted a couple of autozooids and two ‘vibracularia’ of Radulopora radula (Marsson) . The latter are shown as asymmetrical with a curved thorn-like process projecting into the opesia from one side. However, material of this species identified by Voigt and now conserved in the SMF has symmetrical avicularia without this process and are proximolaterally directed ( Figure 23 (f)). In the second species Voigt assigned to this genus, R. minor Voigt, 1968 , from the late Maastrichtian of France and the Netherlands, the avicularia are also symmetrical and lack a lateral process.

Range

Cretaceous (Maastrichtian).

Figures

Figure 23. Radulopora radula (Marsson); Late Cretaceous, early Maastrichtian, Lundegårde, Nordjylland, Denmark. (a,b) SMF 29628; (a) branch fragment; (b) autozooids with closure plates and impressions of opercular sclerites (arrowed). (c,f) SMF 29629; (c) branch bifurcation, including a zooid (arrowed) with partial closure plate; (f) avicularium; (d,e) SMF 29630; (d) autozooids and avicularia; (e) fertile autozooid. Scale bars: a = 1 mm; b, d, e = 200 µm; c = 500 µm; f = 100 µm.