A new species of Taylorius ( Bryozoa : Escharinidae ) from the east coast of South Africa

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The most recent genus to be erected that was previously included in Escharina is Taylorius based on the nature of its pseudoporous frontal shield, regularly paired small heterozooids and setiform avicularian mandibles, fully cleithral ovicells and lack of a peristome.Gordon (2014) proposed new combinations for two fossil species, viz.Taylorius masoni (Brown, 1952) previously Escharina masoni and Taylorius waiparaensis (Brown, 1952) previously Escharina waiparaensis, and erected Taylorius cylindratus (Gordon, 2014) previously Escharina waiparaensis, Taylorius arcuatus (Gordon, 2014) previously Escharina waiparaensis and Taylorius spinosus (Gordon, 2014) as a new species from New Zealand.The confused synonomy of Escharina waiparaensis was, in particular, dealt with comprehensively and clarified by Gordon (2014).Furthermore, he noted that specimens from South Africa and Australia require further taxonomic examination as his preliminary opinion suggested that these warrant placement in the genus Taylorius, with the African specimens representing a potentially new species.
This study aims to give an account of a new species of Taylorius, Taylorius nyembezi sp.nov., from specimens collected by the R.V. Meiring Naudé; previously reported from South Africa as Escharina waiparaensis by Hayward & Cook (1983) and alluded to in Gordon (2014).
The material was sub-sampled and later bleached in a weak 5% NaOCl (domestic bleach) solution in order to remove all debris and organic material.The sub-sampled specimen was left to dry in a ventilated chamber for 24 hours and then studied by scanning electron microscopy using a JEOL-5200 SEM.Measurements of the morphological features of the relevant specimen were made using an optical eyepiece micrometer; taken mostly in the zone of astogenetic repetition and given in the text as the observed range and mean (the latter in brackets).Measurements (in µm) are given in the text for the following characters: autozooid length (ZL) and width (ZW), orifice length (OL) and width (OW), and anter length (AntL).Mean sinus to OL ratio (SOLR), which is a diagnostic feature for the taxon reported here,was calculated for selected Taylorius species using the following equation: Holotype and paratype specimens were assigned for historical specimens lodged in the collections of the Natural History Collections Department, Iziko Museums of South Africa, Cape Town, and The Natural History Museum, London, respectively.The taxonomic opinion and classification expressed below is based on the most recent opinion of Gordon (2014).

Description
Colony encrusting, forming small, unilaminar, irregular patches.Autozooids broad and flat, rounded distally, weakly elongate-rectangular, occasionally wider mid-length or proximally , ZW 440-640 (514)]; interzooidal boundaries indicated by a smooth, narrow, non-porous strip around the zooids.Frontal shield weakly convex, granular, with numerous relatively close spaced pseudopores; areolar-septular pores mostly absent, occasionally 1-2 per zooid along lateral margin.Orifice with distinct transversely D-shaped anter that is wider than long ]; sinus longer than wide with distal corners curving inwards and proximal end rounded; proximal margin of anter, upon which denticled condyles are set, slopes upwards towards the sinus opening, with lateral corners deeply notched; four equally sized large spine bases present with one shorter pair of spines positioned distally and larger pair positioned mediolaterally on either side of orifice.Small, paired, lateral-oral avicularia present at level of sinus; slightly oval-shaped with complete crossbar.One ovicell present; at the growing edge; ooecium appearing as a low bulge, the exterior skeletal surface cryptocystal, granular, imperforate; orifice distorted.Mural communication pores set low in lateral walls inset in buttressed recesses; distal transverse wall with 1-3 large multiporous septula.Ancestrula not seen in examined material.

Remarks
Taylorius nyembezi sp.nov.was first reported from South Africa as Escharina waiparaensis (Brown, 1952) by Hayward & Cook (1983).These authors noted that the South African specimens were interesting in that they were the only representation of E. waiparaensis outside of New Zealand, where this species was reported from the Miocene (Brown 1952) and Pliocene (Brown 1954), and as extant from Three Kings Islands, New Zealand, by Powell (1967).Hayward & Cook (1983) remarked that the specimens were 'identical' to the recent specimens (BMNH 1964.8.12.59C, 59D) reported by Powell (1967), which presumably they had examined.Subsequently Gordon (2014) erected six new species (viz., Taylorius arcuatus, T. cylindratus, T. incognitus, T. masoni, T. spinosus, T. waiparaensis) for the same recent specimens of the New Zealand material and together with the fossil species erected a new genus (viz.Taylorius).Gordon (2014) noted that the South African material reported by Hayward & Cook (1983) is potentially a new species with placement in Taylorius.
Taylorius nyembezi sp.nov. is most similar to T. waiparaensis, T. arcuatus and T. cylindratus.T. nyembezi differs from T. waiparaensis (see Figures 10H, 11A-C in Gordon 2014) in colony form, which is encrusting in the former and bilamellar-foliaceous in the latter, as well as in the metrics of zooids and orifices (see Table 1).The anter shape of T. arcuatus, T. cylindratus and T. nyembezi are all very similar, but the most obvious features distinguishing the latter is its relative long sinus (i.e. it is longer relative to total orifice length), the shape of the proximal margin of the anter (seen unequivocally with SEM) and the large size and position of the spine bases (see Figure 10F and G in Gordon 2014).These characters appear to have usefulness in species discrimination within Taylorius.No measurements were done on the ooecium and female orifice of T. nyembezi, as the colony was fragmented, and only one ovicell was observed towards the growing edge.These unique characters are considered sufficient to warrant erecting T. nyembezi as a new species.