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 ordo
Brown, 1952
Fig. 7
;
Table 5
Microporella ordo
Brown, 1952: 257
, figs 189–193.
Microporella ordo
–
Powell 1967: 291
, text-fig. 54.
Material examined
Holotype
NEW ZEALAND
•
Wanganui
,
Castlecliff
;
NZGS
Loc. 4013; late Pleistocene; Castlecliffian Horizon CU3 (ca 0.55 myr);
NHMUK D36809
(figured in
Di Martino
et al.
2017
: fig. 5).
Additional material
(figured)
NEW ZEALAND
• Fragment from large colony, bleached;
Spirits Bay
; Recent;
NIWA 144880
(
Fig. 7
A– C) • Fractured section; Recent;
NIWA 144881
(
Fig. 7D
)
•
Fragment 2, unbleached;
Spirits Bay
; Recent;
NIWA 144882
(
Fig. 7
E–F).
Additional material
(not figured)
NEW ZEALAND
•
1 specimen
; [
33.9655° S
,
171.7723° E
]; depth
92–96 m
; St. TAN1105/42; Recent;
NIWA 73196
•
2 specimens
; [
37.5947° S
,
178.8660° E
]; depth
56–58 m
; St.
TAN1108/239
; Recent;
NIWA 75495
,
75499
•
1 specimen
; [
34.3780° S
,
172.7100° E
]; depth
48 m
; St.
KAH9901/45
; Recent;
NIWA 99099
•
1 specimen
; [
34.3782° S
,
173.0265° E
]; depth
64–65 m
; St.
TAN0906/170
; Recent;
NIWA 56945
•
1 specimen
; [
34.3813° S
,
172.6618° E
]; depth
54 m
; St.
KAH9901/69
; Recent;
NIWA 99072
•
1 specimen
; [
34.3690° S
,
172.8250° E
]; depth
55 m
; St.
KAH9901/25
; Recent;
NIWA 114233
•
1 specimen
; [
34.3600° S
,
172.6968° E
]; depth
46 m
; St.
KAH9901/31
; Recent;
NIWA 128424
.
Description
COLONY. Erect, bifoliate, the largest about 110 ×
75 mm
, with broad branches fused at edges to form a boxwork colony; interzooidal communication Via multiporous septula, elliptical,
55 µm
long by
45 µm
wide, with at least 12 circular pores ca
4 µm
in diameter, placed in the basal lateral walls on distolateral corners of autozooids.
AUTOZOOIDS. Distinct with interzooidal boundaries marked by narrow grooves, rounded rectangular to hexagonal, longer than wide (mean L/W = 1.63). Frontal shield flat to Very slightly conVex, pustulose, the pustules about
20–30 µm
in diameter; marginal areolae numbering about 10, elongate near growing edge (
25–45 µm
long by
15–20 µm
wide), becoming indistinguishable from frontal pores in older zooids; non-marginal pseudopores moderately large (diameter
8–18 µm
), numbering about 20–30, arranged semi-regularly.
Table 5.
Measurements in µm of
Microporella ordo
Brown, 1952
, Recent, Spirits Bay, New Zealand; NIWA 144880, 144882.
N (zooids, colonies)
|
Mean
|
SD
|
Min
|
Max
|
ZL
|
20, 2 |
517 |
±31 |
457 |
557 |
ZW
|
20, 2 |
318 |
±36 |
234 |
378 |
OL
|
20, 2 |
96 |
±5 |
84 |
104 |
OW
|
20, 2 |
151 |
±7 |
130 |
160 |
AvL
|
20, 2 |
86 |
±7 |
72 |
107 |
AvW
|
20, 2 |
80 |
±6 |
71 |
91 |
OvL
|
9, 1 |
406 |
±26 |
362 |
446 |
OvW
|
9, 1 |
390 |
±13 |
374 |
404 |
ORIfICE. Semielliptical, significantly wider than long, hingeline straight to weakly concaVe, with about 15 teeth, equal in size except for slightly longer outer one or two pairs; oral spines lacking; folded back transverse vertical wall of distal zooid forming a slightly elevated crescent secondary rim above the distal margin of the primary orifice; operculum smooth.
ASCOPORE fIELD.As a raised area of gymnocystal calcification at approximately same leVel as orifice but beneath leVel of adjacent frontal shield, located moderately close to orifice hingeline, about
60–70 µm
below, separated from it by non-porous pustulose cryptocyst; reniform to transVersely elliptical, 45 ×
60 µm
, opening heart-shaped, 25 ×
40 µm
, coVered by filigree sieVe plate, a narrow, bifurcated tongue usually projecting from the distal edge.
AVICULARIUM. Single, moderately large, present in the majority of autozooids, positioned level with or slightly distally of and almost abutting the ascopore, oriented distolaterally to almost laterally; crossbar complete; opesia semielliptical; rostrum short, teat-shaped, the distal end rounded, distinct channel present. Mandible in dried material with short (ca
90–110 µm
) pointed seta, narrow throughout, hooked on underside, lying across or a little proximal of ascopore when open.
OVICELLS. Very large, often covering frontal shield of distal zooid as far as ascopore, bulbous, subcircular or a little longer than wide, non-personate; calcification similar to frontal shield but with finer pustules, continuous with frontal shield of distal zooid; small pseudopores distributed across entire surface, more closely spaced compared to those on the frontal shield, radially aligned near margins; orifice of oVicellate zooids hidden in frontal view.
Remarks
The description given above and measurements in
Table 5
are based on Recent examples of this species which show the morphology of the species better than the
type
and other fossil material. Although very similar to
Microporella hyadesi
in its general appearance,
M. ordo
is easily distinguished by its heartshaped ascopore with filigree sieVe plate and narrow bifurcated tongue, in addition to the non-personate ovicells.
The present-day range of the species extends from NW of the Three Kings Islands at Middlesex Bank to Ranfurly Banks off East Cape,
New Zealand
(33.9–
37.6° S
; depth
46–96 m
).