REDISCOVERYOFA TYPE SPECIMEN OF <i>RETEPORA PLUMA</i> PHILLIPS, 1836, THE TYPE SPECIES OF <i>PENNIRETEPORA</i> D'ORBIGNY, 1849 (FENESTRATA, BRYOZOA), AND REPLACEMENT OF ITS NEOTYPE

Abstract

Penniretepora d'Orbigny, 1849, is a widespread and distinctive Upper Palaeozoic acanthocladiid bryozoan. A syntype of the type species Retepora pluma Phillips, 1836, has been located, illustrated and designated lectotype, and the neotype designated in 1974 is set-aside. Introduction taxonomic and other problems that this caused were well-known (Edmonds 1977). Penniretepora d'Orbigny, 1849, is a distinctive In the 1970s during a generic revision of the bryozoan that forms pinnate colonies whose zoargenus Penniretepora undertaken by Foluso Olaloye, ium consists of a main or primary stem from which Phillips' specimens of Retepora pluma could not be arise secondary lateral branches that in turn may located (Olaloye 1974). In fact, other type specimens develop tertiary branches (Fig. 1A). Autozooecia appeared to be missing, leading to the designation are arranged in two longitudinal rows along all of a neotype for at least one bryozoan species branches and open out on the obverse surface only. (Tavener-Smith 1965, 1981). As a result of not As with bryozoans of the order Fenestrata, Elias locating Phillips' specimens, Olaloye collected a and Condra, 1957, the reverse surface is barren. number of colonies from Florence Court (one of The genus Penniretepora was named by the Phillips' type localities) and designated one of these French palaeontologist Alcide d'Orbigny (1849, (BELUM K.4000) the neotype (Fig. ID), which p. 501) who designated the Mississippian species showed an abraded obverse surface. She also illu Retepora pluma Phillips, 1836, as the type species strated and described several others BELUM (Fig. 1BC). Phillips described this taxon from K4001-4005, which she deposited in the Ulster various localities in Yorkshire (Whitewell in Bolland, Museum (BELUM) (Fig. 1E-F). and Greenhow Hill) and from Florence Court, near More recently, during ongoing revisions of Enniskillen, Co. Fermanagh (Phillips 1836, p. 199). various Mississippian bryozoans, material in the For his Yorkshire monograph, John Phillips Natural History Museum, London, has been ex utilised several collections, but in particular that amined. As a result several Phillips type specimens assembled by William Gilbertson, a chemist from have been located, of Calamopora incrustans Preston. Eventually, this material was sold in 1841 [=Fistulipora incrustans] (see Wyse Jackson and to the British Museum (Natural History) [now Bancroft 1995, p. 133) and now a single syntype of the Natural History Museum (NHM)], London Retepora pluma [=Penniretepora pluma] (NHM (Cleevely 1983). Subsequently, the material was D33096) (Fig. 1C). Recently, extensive research on accessioned but over time much of it could not other components of the Gilbertson Collection has be matched with Phillips' 1836 publication. The resulted in the identification of a considerable Irish Journal of Earth Sciences 29 (2011), 15-18 C 2011 Royal Irish Academy doi: 10.3318/IJES.2011.29.15 15 This content downloaded from 157.55.39.104 on Sun, 19 Jun 2016 06:36:48 UTC All use subject to http://about.jstor.org/terms 16 Irish Journal of Earth Sciences (2011) Fig. I—Penniretepora from the Mississippian of Ireland and Britain. (A) Penniretepora elegans Young and Young, 1875; GAGM 01-53wg; Brigantian, Mid to Late Mississippian; Dykehead Pit, High Blantyre, Scotland, showing typical zoarial form with primary (main), secondary and tertiary (lateral) branches; X2.5; (B) Phillips' original figures of Retepora plumer, (C) Penniretepora pluma (Phillips, 1836); lectotype, NHM D33096; Gilbertson Collection; Whitewell in Bolland, Yorkshire. England, showing zoarial pattern corresponding with Phillips' original drawing 13n, X2.5; (D-F) Penniretepora pluma (Phillips, 1836) from the Visean, Mississippian of Florence Court, Co. Fermanagh; (D) Olaloye's neotype, BELUM K4000 showing worn obverse surface and development of lateral branches, XI5; (E) BELUM K4002, obverse surface showing typical zoarial pattern with lateral branches diverging at moderately high angle from the main stem. Autozooecial apertures with distally inflated peristomes that produce a characteristic apertural shape. XI5; (F) BELUM K4005, as E but with central sinuous carina along main stem, X15. (Fig. 1D-F courtesy of the Ulster Museum) number of Phillips type specimens (Nikolaeva and The purpose of this paper is to document the Morgan 2010). rediscovery of a Phillips syntype of Retepora pluma; According to Article 75.8 of the International designate it as lectotype; briefly describe the speci Code of Zoological Nomenclature (ICZN 1999, men; and to set aside the neotype designated by p. 86) if Olaloye (1974). A fuller description of the species will be provided in due course following a compre the name-bearing type... of the nominal hensive assessment of the British and Irish acantho species-group taxon that was presumed lost cladiid bryozoans. is found still to exist, on publication of that discovery the rediscovered material again Phillips' syntype of Retepora pluma becomes the name-bearing type and the neotype is set aside (unless, following an Given that the gross zoarial form of the specimen in application, the Commission rules that the the NHM (D33096) (Fig. 1C) matches that illu neotype is to be retained as the namestrated by Phillips (1836, plate 1, figures 13n and 15) bearing type). (Fig. IB) there is no reason to suggest that it is not This content downloaded from 157.55.39.104 on Sun, 19 Jun 2016 06:36:48 UTC All use subject to http://about.jstor.org/terms Patrick N. Wyse Jackson—Rediscovery of a type specimen of Rctepora pluma Phillips, 1836 17 the same specimen, and it is accepted here as being one of Phillips' original syntypes of Retepora pluma. Although the Phillips specimen does not show the obverse surface, there is sufficient detail pre served to place it in Penniretepora without any doubt as to its identification. Consequently, there is no scientific reason to request retention of the neotype (BELUM K4000) as per Article 75.8 (see above). PHYLUM BRYOZOA Ehrenberg, 1831 CLASS STENOLAEMATA Borg, 1926 ORDER FENESTRATA Elias and Condra, 1957 FAMILY ACANTHOCLADIIDAE Zittel, 1880 GENUS PENNIRETEPORA d'Orbigny, 1849 Penniretepora pluma (Phillips, 1836) Fig. 1B-E vl836 Retepora pluma Phillips, p. 199, pl. 1, figs 13-15. 1844 Glauconome pluma (Phillips); M'Coy, p. 199. 1849 Penniretepora pluma (Phillips); d'Orbigny, p. 501. vl974 Penniretepora pluma (Phillips); Olaloye, p. 486, pi. 16, figs 1-4. 1975 Penniretepora pluma (Phillips); Graham, p. 6, pi. 2, figs 1-2, 5-8, pi. 4, fig. 4. Lectotype As Phillips (1836) failed to designate a holotype and as only one of his syntypes has been located, it is herein designated lectotype. NHM.D33096; White well in Bolland, Yorkshire, England; Mississippian; Gilbertson Collection. Original description 'Penniform: branches and branchlets round; two rows of large alternate pores; reverse striated.' (Phillips 1836, p. 199). Description of lectotype Colony forms a small flat pinnate expansion 19mm high by 6mm wide; main stem is straight to slightly curved distally, parallel-sided and maintains a con stant diameter of 0.6 mm along its length. Thinner (0.3 mm) parallel-sided secondary branches ar ranged opposite or slightly offset in pairs either side of main stem; these diverge from the main stem at a low angle of between 15 and 20 degrees. They are closely spaced 1.00-1.2 mm apart. Longest secondary branch 5 mm. Tertiary branches rare, offset at 20 degrees. No lateral branches fuse. Reverse surface on all branches gently rounded with seven (on main stem) to five (on laterals) longitudinal straight to slightly sinuous low ridges along length; small stylets developed on ridge crests. Autozooecial chambers on the main stem not seen; on lateral branches chambers arranged in two rows on stems, triangular in shape in deep tangential section.