Buskia waiinuensis, Martino & Taylor & Gordon & Liow, 2017

Martino, Emanuela Di, Taylor, Paul D., Gordon, Dennis P. & Liow, Lee Hsiang, 2017, New bryozoan species from the Pleistocene of the Wanganui Basin, North Island, New Zealand, European Journal of Taxonomy 345, pp. 1-15 : 3-5

Buskia waiinuensis sp. nov.

urn:lsid:zoobank.org:act:A5EC216B-6E64-4A39-A77E-47EA338DDF53

Fig. 1 , Table 1

Diagnosis

Colony encrusting, with a stolonal system branching at variable angles. Stolons thick, showing concentric lines. One or two zooids per internode, elongated elliptical, with the frontal surface convex and showing concentric lines. Orifice circular or oval, with one or two lateral cystid appendages.

Etymology

From Waiinu Beach, the type locality.

Material examined

Holotype

NEW ZEALAND: Nukumaru Limestone , Waiinu Beach (R22/f0270), Nukumaruan, Pleistocene ( GNS BZ 335 ).

Description

Colony entirely encrusting, consisting of a somewhat variable ramifying stolonal system with sidebranches given off stolonal axis dichotomously, at 45° or at 90°, forming square or rectangular sectors ( Fig. 1 A–B). Stolons apparently fused at contact point with one another, thick, 50–65 μm in diameter. Stolonal walls shallow, ornamented with very thin, closely spaced, concentric lines. Zooids sparsely distributed ( Fig. 1 A–B), irregularly positioned, usually one or two per stolonal internode, oriented with long axis parallel or perpendicular to stolonal axis, depending on overgrowth direction, elliptical, elongated and narrow (mean L/W = 2.72). Frontal surface evenly curved and slightly convex, ornamentation similar to that of stolons but with thicker concentric lines ( Fig. 1 C–D). Orifice circular or transversely oval ( Fig. 1 C–D). One or two cystid appendages visible laterally to orifice ( Fig. 1 C–D), 58–68 μm long.

Remarks

Four fossil species of Buskia have been described, all preserved by bioimmuration and from European localities. In order of stratigraphic age these are: B. nigribovis Todd, 1994 from the Jurassic of France, B. inexpectata Voigt, 1979 from the Maastrichtian of the Netherlands, B. fowleri Todd, 1996 from the Eocene of England and B. hachti Voigt, 1979 from the Pliocene of France. At the present day, Buskia is represented in New Zealand by two non-indigenous species that are considered as established, viz B. nitens Alder, 1856 and B. socialis Hincks, 1887 ( Gordon & Mawatari 1992; Gordon et al. 2009).

Buskia waiinuensis sp. nov. differs from B. nigribovis in being regularly ramifying, with much thicker stolons (50–65 μm vs 14–24 μm) and a limited number of cystid appendages. The latter character also distinguishes the new species from B. fowleri , which in addition has densely populated stolons, as does B. inexpectata . Buskia hachti has a stolon width similar to that of the new species (ca 50 μm), but more elongated zooids (400–650 μm vs 308–438 μm) and no cystid appendages. Of the two Recent species present in New Zealand, B. socialis differs in being erect, while B. nitens has narrower stolons (ca 25 μm).

Distribution

The single known bioimmured colony is preserved as a mould bioimmuration on the underside of an erect cyclostome bryozoan which overgrew the soft-bodied ctenostome. It was collected from the Nukumaru Limestone (2.29–2.08 Ma, Nukumaruan, Pleistocene) at Waiinu Beach and represents the first fossil record of the genus outside Europe.

Figures

Fig. 1. Buskia waiinuensis sp. nov., holotype (GNS BZ 335), Nukumaruan, Pleistocene, Nukumaru Limestone, Waiinu Beach, New Zealand. A. General view of the bioimmured colony, showing the regular development of the stolonal pattern. B. Close-up of a sector of the colony. C. Close-up of a zooid with oval orifice. Note the cystid appendage lateral to the orifice and the concentric lines on the zooidal and stolonal surface. D. Close-up of a zooid with a circular orifice and two cystid appendages lateral to the orifice. Scale bars: A = 1 mm; B = 200 µm; C = 50 µm; D = 100 µm.