Synopsis of ‘ onychocellid’ cheilostome bryozoan genera
Author
Taylor, Paul D.
Author
Martha, Silviu O.
Author
Gordon, Dennis P.
text
Journal of Natural History
2018
J. Nat. Hist.
2018-07-03
52
25 - 26
1657
1721
http://dx.doi.org/10.1080/00222933.2018.1481235
journal article
10.1080/00222933.2018.1481235
1464-5262
4747141
63A31AD2-F049-42CB-A45B-557014DC286E
Genus
Floridinella
Canu and Bassler, 1917
(
Figure 12
)
Type
species
Floridinella vicksburgica
Canu and Bassler, 1917
, by original designation.
Oligocene, Vicksburgian (= Rupelian),
Escambia County
,
Alabama
,
USA
.
Diagnosis
Colony encrusting (
Figure 12
(a)) or tubular erect (
Figure 12
(b)). Autozooids elongate subhexagonal; zooidal boundaries grooved. Cryptocyst extensive, granular. Gymnocyst lacking or very narrow. Opesia terminal, occupying one-third to half of frontal surface; constricted just beyond mid-length (
Figure 12
(b)), proximal edge straight to slightly concave. Ovicells hyperstomial; opesia enlarged in ovicellate autozooids; ooecia?cryptocyst-like. Avicularia equivocal (see below).
Remarks
Floridinella
resembles
Floridina
but supposedly lacks avicularia and has opesiae with less concave proximal edges. Although this genus was explicitly stated by
Canu and Bassler (1917)
to lack avicularia,
Cook and Bock (2001)
re-examined
syntype
specimens of the type species and found that Canu and Bassler had retouched their figures to remove the small disto-lateral avicularia present on the surfaces of the ovicells. According to Cook and Bock, these avicularia have a triangular rostrum and a calcified pivotal bar.
Figure 12.
(a,b)
Floridinella vicksburgica
Canu and Bassler
; Oligocene, Vicksburgian (= Rupelian), west bank of Conecuh River, Escambia County, Alabama, USA; (a) NHMUK BZ 8213, part of an encrusting colony showing autozooid and?kenozooids (left), one of which is arrowed; (b) NHMUK BZ 8214, autozooids in a tubular erect colony. (c,d)
Floridinella jeffersoni
Taylor and McKinney
; Cretaceous, Maastrichtian, Prairie Bluff Chalk, Jefferson, Marengo County, Alabama, USA; holotype, NHMUK BZ 5043(1a); (c) non-ovicellate autozooid; (d) ovicellate autozooids. Scale bars: a = 500 µm; b, d = 200 µm; c = 100 µm.
Winston (2016)
regarded
Floridinella
as a junior synonym of
Ammatophora
Norman, 1903
. However, the
type
species of the latter genus –
Membranipora nodulosa
Hincks, 1877a
– has large tubercles between the zooids and semi-elliptical opesiae unlike the trifoliate opesiae of the
type
species of
Floridinella
.
Canu and Bassler (1920
, p. 229) described the ovicell of
Floridinella
as ‘endozooecial and separated from the zooecia by a fold’. Whether the ooecium is gymnocystal or cryptocyst-like is uncertain. In the oldest species assigned to this genus –
F. jeffersoni
Taylor and McKinney, 2006
from the Maastrichtian of
Alabama
– the ovicell is hyperstomial with a cryptocyst-like ooecium (
Figure 12
(d)). This species also shows a trace of very narrow gymnocyst around the margins of the zooids (
Figure 12
(c)).
Range
Cretaceous (Maastrichtian) to Recent.