Review of palaeozygopleurid gastropods (Palaeozygopleuridae, Gastropoda) from Devonian strata of the Perunica microplate (Bohemia), with a re-evaluation of their stratigraphic distribution, notes on their ontogeny, and descriptions of new taxa
Author
Frýda, Jiří
Author
Ferrová, Lenka
Author
Frýdová, Barbora
text
Zootaxa
2013
3669
4
469
489
journal article
10.11646/zootaxa.3669.4.3
13b37162-4203-4029-985f-3bd89ff3cb10
1175-5326
222578
CD30BE63-C779-45CD-A25E-D633BBC0B9FF
Palaeozygopleura lukesi
sp. nov.
Fig. 3
A–N
Holotype
.
UUG JF 922 (
Fig. 3
A–C, H, and I).
Paratypes
.
The shells figured herein as
Figure 3
D (
paratype
A; UUG JF 923),
Figure 3
E,F (
paratype
B; UUG JF 924),
Figure 3
G (
paratype
C; UUG JF 925),
Figure 3
J,M (
paratype
D; UUG JF 926),
Figure 3
K (
paratype
E; UUG JF 927),
Figure 3
L,N (
paratype
F; UUG JF 928), and 32 unfigured specimens (UUG JF 929–960). All
paratypes
come from the
type
locality.
Type
locality.
Císařský lom quarry, S of the village of Konĕprusy (
49°55'00.99"N
,
14°3'36.420"E
).
Type
horizon.
Middle part of the Konĕprusy Limestone (Praha Formation), at the same level as
Konepruselia zaki
Frýda and Ferrová, 2011.
Etymology.
After our friend Pavel Lukeš, who has contributed considerably to our understanding of the Devonian stratigraphy of the Barrandian area (
Bohemia
).
Diagnosis.
Palaeozygopleura
with slightly convex sides, convex whorl profile; whorls symmetrically arched, ornamented by prominent, regularly spaced, asymmetrically curved opisthocyrt costae; costae covering lateral as well as basal surface of whorls (
Fig. 3
F); collabral costae culminating slightly above mid-whorl; angle between costae and lower as well as upper suture about 45 degrees; pleural angle of adult shell about 15 degrees; apical angle at first three whorls about 28 degrees; diameter of first half of whorl about
0.27 mm
.
Description.
High-spired, multiwhorled dextrally coiled shell with up to 10 whorls; sides of shell slightly convex; pleural angle about 15 degrees, sutural slope angle about 17 degrees; lateral whorl sides between sutures very convex and symmetrically arched; sutures relatively deep; base of whorls rounded, anomphalous; lateral, basal parts of whorls ornamented by prominent, asymmetrical arched costae; costae forming wide asymmetrical arched sinus; sinus culminating above middle of whorl; angle between costae, lower as well as upper suture about 45 degrees; distance between costae about double that of costae; protruding protoconch relatively large; diameter of first half of whorl about
0.27 mm
, that of embryonic chamber about
0.14 mm
; first preserved costae from end of first whorl; preservation of shell not allowing for determination of exact position of protoconch/teleoconch boundary.
Comparison.
The deep, asymmetrically arched costae differ
P. lukesi
from the majority of the species of genus
Palaeozygopleura
, which have either a straight or symmetrical arched costae. Only three Early Devonian palaeozygopleurid gastropods:
P. devonicans
,
Bojozyga mira
, and
P. chlupaci
Frýda, 1993
, have distinctly asymmetrically arched costae. Shells of
P. lukesi
have very convex lateral sides of the whorls, in contrast to
P. devonicans
, where the moderately convex whorls are flattened in their median region (Horný 1955: pl. 1, figs 1, 2). Shells of
P. lukesi
have a much wider pleural angle than
B. mira
. In addition,
B. mira
has less convex whorls, which are rather flat below the upper suture, and a much finer, and less arched costae. The Pragian aged
P. lukesi
resembles the Lochkovian
P. chlupaci
by the shape of its costae, but it differs from the latter species by much lower whorls, a wider apical angle, and symmetrically arched whorl side between sutures.
Pathology.
An anomalous development of the ornamentation was found on the lateral whorl in one specimen (UUG JF 928:
Fig. 3
N), which was most likely caused by shell repair after a failed predation attack. Similarly damaged shells of other species of
Palaeozygopleura
were described in the Pragian
P. a li na e
(see Horný 1955: pl. III, fig. 4), in the Lochkovian
P. chlupaci
(see Frýda 1993: fig. 2.6), and also occur in the Emsian
P. vaneki
Frýda, Ferrová, Berkyová and Frýdová, 2008
(this study).
Stratigraphic and geographic distributions.
Palaeozygopleura lukesi
is only known from its
type
locality and horizon.