Hemipustulopora tuoyuan Liu & Liu & Zágoršek 2019, n. sp.

Hemipustulopora tuoyuan n. sp.

(Figs 46–49)

lsid:zoobank.org:act: D0A1C723-B08E-4F19-B35A-D489DE51CF01

Diagnosis. Colony large, autozooids arranged in indistinct transversal rows. Gonozooid very large, extending over up to 20 autozooidal tubes, frontal wall indistinct. Ooeciopore elongated to circular, attached to the autozooidal tube. Pseudopores large, numerous, often close by radially arranged laminae.

Holotype. Specimen MBM 284503 from Jiaozhou Bay (Figs 46–48).

Paratypes. Specimens MBM 284360, MBM 284358 (Jiaozhou Bay) and MBM 284445 (Lingshan Island).

Additional material. More than 10 colonies from samples MBM 194701, MBM 0 92324, MBM 284363, MBM 284361, MBM 284385, MBM 194797, MBM 0 92236 and MBM 194840 (Jiaozhou Bay), MBM 194797, MBM 0 92370 (Lingshan Island), MBM 284502 from Nanhai road.

Etymology. Referring to the ellipsoidal shape of the ooeciopore. In Chinese phonetic transcription, ‘ellipsoidal’ is tuǒyuán.

Description. Colony erect, lobate, large, branches up to 2 mm wide, distance between bifurcations up to 3.5 mm. Autozooids densely arranged, in somewhat transverse rows, peristomes short, apertures only on one side, almost circular, approximately 160–180 µm in diameter. Pseudopores large (diameter approximately 13–15 µm) closed by radially arranged laminae (Fig. 48). Gonozooid very large, perforated by autozooidal tubes, frontal wall only slightly elevated; pseudopores the same as that of autozooidal tubes (diameter approximately 9–10 µm), and therefore, the gonozooid almost indistinct. Ooeciopore elongate, oval to elliptical (up to 210 µm wide by 80–100 µm long), rarely circular (diameter of approximately 120 µm). Ooeciostome slightly turned towards the direction of growth, attached to one autozooidal tube. Protoecium not observed. Dorsal side of the colony with distinct, concentric growth lines and minute pseudopores.

Remarks. The species is similar to Entalophora multipora MacGillivray, 1895 (p. 140, pl. 21, fig. 1) in the general shape and size of the colony and the arrangement of autozooid. However, no gonozooids have been described in the latter species. Diastopora patina Lamarck as described by MacGillivray (1895, p. 130, pl. 20, figs 4, 5) has a similar arrangement of autozooidal tubes, but differs in having much smaller gonozooids, which are not perforated by autozooidal tubes.

The species belongs to Hemipustulopora because of the large colonies with wide branches and apertures only on one side, arranged in slightly transverse rows; frontal, much extended gonozooid; and smooth dorsal side with visible, concentric growth lines. Hemipustulopora has been recorded only from South Africa (Brood 1976).

Filisparsa d’Orbigny, 1853 is another very similar genus in having apertures only on one side and a smooth back side of the branches. The type species of Filisparsa is, however, Early Cretaceous and has rather narrow, nonflabellate branches.

A few specimens (MBM 284502 from Nanhai Road) have circular ooeciopore (diameter ca. 120 µm), with ooeciostome directed upwards. This type of ooeciopore is situated close to the neighbouring autozooidal tube, but usually not directly attached to it. We consider this difference as within species variability.

Occurrence. Nanhai Road, Jiaozhou Bay and Lingshan Island.