Conopeum ongleyi ( Brown, 1952 ), 2020

Gordon, Dennis P., Sutherland, Judy E., Perez, Brenda A., Waeschenbach, Andrea, Taylor, Paul D. & Di Martino, Emanuela, 2020, The bryozoan genus Conopeum (Electridae) in New Zealand, with description of a new species and discussion of the morphological and genetic characters of Conopeum seurati (Canu, 1928), Journal of Natural History (J. Nat. Hist.) 54 (15 - 16), pp. 947-970 : 963-965

Conopeum ongleyi ( Brown, 1952) n. comb. ( Figure 7 )

Electra ongleyi Brown, 1952: 47 , fig. 8.

Villicharixa ongleyi: Gordon et al. 2009: 289 .

Material examined

Holotype: NHMUK D.36532, Petane, Hawke’s Bay, Pleistocene; paratype: NHMUK D.32511, Waipukurau Gorge , Central Hawke’s Bay, Pliocene. NIWA 132867 , 41.2967° S, 175.4753° E, by stream confluence under ‘ Banana Bridge’, White Rock Road, Wairarapa, Pleistocene, coll. D.P. Gordon 12 January 2017; NIWA 132868 , 41.2975° S, 175.4753° E, up farm drive west of ‘ Banana Bridge’, White Rock Road, Wairarapa, Pleistocene, coll. D.P. Gordon 22 February 201988017; NIWA 134507 , 41.2973° S, 175.4754° E, up farm drive west of ‘ Banana Bridge’, White Rock Road, Wairarapa, Pleistocene, coll. P.D. Taylor 22 February 2017.

Description

Colony encrusting, unilamellar, multiserial, up to ~ 15 mm maximum spread.

Mature autozooids in zone of astogenetic repetition arranged quincuncially, subrectangular, tending to be a little wider midlength; distinct interzooidal furrow. Opesia elongateoval, surrounded by raised inwardly sloping cryptocyst ( Figure 7 (a–e)) that is more or less of equal width throughout and higher than gymnocyst, its surface with conspicuous tubercular granules that are somewhat directed downwards from overhanging lower side of cryptocyst ( Figure 7 (e)), lacking or almost completely so on vertical thin distal margin. Gymnocyst variable, ranging from narrow to little evident laterally and moderately long to very short proximally ( Figure 7 (a–d)). Periopesial spine bases 15–20, the most distolateral pair largest ( Figure 7 (c)).

Kenozooids rare, usually formed at bifurcation of zooid row or in other locations where space inadequate to form autozooid; elongate with longitudinally narrow opesia, and cryptocyst as in autozooids.

Interzooidal communications via small multiporous chambers low on lateral walls. Inner side of lateral walls weakly ridged ( Figure 7 (e)). Distal transverse wall with a pair of ridges that descend to the zooid floor, creating three recesses ( Figure 7 (d)); muscle insertions interpreted as occurring in lateral pair of recesses in life, with middle recess for communication pores.

Ancestrula and early astogeny not seen.

Measurements

Paratype, NHMUK D.32511, Waipukurau Gorge, Central Hawke’s Bay, Pliocene :

ZL 494–667 (575) [N = 20]; ZW 229–400 (314) [N = 20]; OpL 303–384 (347) [N = 20]; OpW 130–214 (179) [N = 20]; PCrL 31–75 (53) [N = 20]

Remarks

Gordon et al. (2009) transferred the species from Electra Lamouroux, 1816 to Villicharixa Gordon, 1989 . As has come to be appreciated from the work of Nikulina (2007, 2010), Electra , as circumscribed, was highly heterogeneous,not only morphologically but genetically, and what was one genus now comprises five genera. Inter alia, all morphologically coherent Electra species have a conspicuously pitted gymnocyst and a very narrow smooth cryptocyst. In C. ongleyi the gymnocyst is smooth and non-pitted and there is a fairly well-developed granular periopesial cryptocyst. Gordon et al. (2009) transferred C. ongleyi to Villicharixa not only because it clearly did not belong to Electra but also because of the many small spine bases along the lateral margins and the buttresses in the distal transverse wall. In the event, the species is better included in Conopeum ; periopesial spines in Villicharixa , hair-like in life, are much more numerous, numbering up to 50, and the zooidal wall is constructed in a peculiar way that differs significantly from that in C. ongleyi – a continuous chamber runs under the length of each lateral wall, as well as proximally and distally. Numerous openings from the zooidal interior into this common chamber are separated by small vertical buttresses.

A closely related species is an unnamed taxon from southern Australia illustrated by Bock (2009) and compared to Conopeum tenuissimum ( Canu, 1908) , a Pliocene Argentinian species. It resembles C. ongleyi in most respects but either completely lacks small marginal spines or has only 1–2 such spines.

Figures

Figure 7. Conopeum ongleyi (Brown, 1952): (a), holotype, NHMUK D.36532, Petane, Hawke’s Bay, Pleistocene; (b, c, e), NIWA 134507, White Rock Road, Wairarapa; D, NIWA 132867, White Rock Road, Wairarapa, New Zealand. (a–c), Autozooids showing granular cryptocyst, numerous small spine bases with a larger distolateral pair, and smooth proximal gymnocyst. D, Distal ends of three tilted autozooids, showing buttresses on transverse wall. E, Inner face of autozooid tilted laterally to show steeply sloping granular cryptocyst slightly overhanging lateral wall. Scalebars: (a–d), 200 μm; E, 100 μm.