Erect bifoliate species of Microporella (Bryozoa, Cheilostomata), fossil and modern Author Martino, Emanuela Di A7905C48-FF37-4D27-BCCE-F0560AF040A2 Natural History Museum, University of Oslo, Norway. e.d.martino@nhm.uio.no Author Taylor, Paul D. 7AFF2929-DF5B-46B2-94E6-B26B396CC2C8 Departments of Earth and Life Sciences, Natural History Museum, London, United Kingdom. p.taylor@nhm.ac.uk Author Gordon, Dennis P. DD9C0F3A-8512-4AC8-B395-7687CE3FC565 National Institute of Water & Atmospheric Research, Wellington, New Zealand. dennis.gordon@niwa.co.nz text European Journal of Taxonomy 2020 2020-07-02 678 1 31 journal article 21572 10.5852/ejt.2020.678 57a241fd-5993-4064-b152-b00ee0a46e2a 3928412 C230401F-3AD1-43D8-9C82-1DEDF5CF40FD Microporella bifoliata Ulrich & Bassler, 1904 Fig. 1 ; Table 1 Microporella ? bifoliata Ulrich & Bassler, 1904: 417 , pl. 103, figs 6–8. Microporella ? bifoliata – Canu & Bassler 1923: 121 , pl. 20, figs 7–11. Material examined Lectotype (designated here) USA • Syntype of Microporella bifoliata Ulrich & Bassler, 1904 ; Maryland , Cordova ; Miocene ; Choptank Formation ; USNM 68592A ( Fig. 1 A–B). Paralectotype (designated here) USA • Syntype of Microporella bifoliata Ulrich & Bassler, 1904 ; Maryland , Cordova ; Miocene ; Choptank Formation ; USNM 68592B ( Fig. 1 C–D) . Other material USA • 4 specimens , syntypes of Microporella bifoliata Ulrich & Bassler, 1904 ; Maryland , Cordova ; Miocene ; Choptank Formation ; USNM 68592C to 68592F . Description COLONY. Erect with bifoliate fronds up to several cm wide, curved; colony base and interzooidal communication not observed. AUTOZOOIDS. Distinct, separated by narrow grooVes, rectangular, longer than wide (mean L/W = 1.76). Frontal shield flat; marginal areolae typically numbering about 16 (12–18), Variable in size ( 15–40 µm ), funnel-shaped, sometimes subdivided internally; reduced number of non-marginal pseudopores, placed more centrally on the frontal shield, irregularly spaced. PRIMARY ORIfICE. Terminal, semielliptical, widest medially, hingeline slightly concave, without teeth or condyles; oral spines lacking; no peristome. ASCOPORE fIELD. A narrow, raised area of gymnocystal calcification beneath leVel of adjacent frontal shield but at approximately same leVel as orifice, located Very close to its hingeline; elliptical, ca 35 × 50 µm , distal margin with projecting, semielliptical tongue leaVing a crescent-shaped opening, ca 10 × 30 µm , with radial spines. AVICULARIUM. Single, located at the same level of ascopore, oriented laterally; crossbar complete; opesia semielliptical; rostrum subtriangular, the distal end a little rounded, not channelled. Fig. 1. Microporella bifoliata Ulrich & Bassler, 1904 , Miocene, Choptank Formation, Maryland, USA. A–B . Lectotype USNM 68592A. A . General view of the branch fragment. B . Group of zooids, mostly ovicellate. C–D . Paralectotype USNM 68592B. C . Group of autozooids. D . Close-up of an autozooid. Scale bars: A = 1 mm; B–C = 200 µm; D = 100 µm. Table 1. Measurements in µm of Microporella bifoliata Ulrich & Bassler, 1904 , Miocene, Choptank Formation, Maryland, USA; lectotype USNM 68592A, paralectotype USNM 68592B.

N (zooids, colonies)	Mean	SD	Min	Max
ZL	16, 2	509	±73	385	662
ZW	16, 2	290	±27	245	330
OL	10, 2	91	±4	85	98
OW	10, 2	114	±9	102	126
AvL	16, 2	104	±12	78	122
AvW	16, 2	86	±14	62	116
OvL	8, 1	243	±12	231	261
OvW	8, 1	273	±27	238	312

OVICELL. Prominent, circular in outline, not personate and not obscuring orifice; calcification similar to frontal shield; pseudopores variable in number, scattered over entire surface, variably spaced. Remarks This extinct species was described from the Miocene (Choptank Formation 12.6–14.4 Ma; Andrews 1988 ) of Maryland ( Fig. 1 ). The form of the mandible is not known in this fossil species, but the fact that the avicularia have closed distal ends without channels may suggest that mandibles were not setose and had a shape identical to that of the rostrum.