Application of morphometric techniques for taxonomic revision of Berabichia oratrix (Orłowski, 1985) (Trilobita, Cambrian) from the Holy Cross Mountains, Poland
Author
Żylińska, Anna
Author
Kin, Adrian
Author
Nowicki, Jakub
text
Geodiversitas
2013
2013-09-27
35
3
505
528
http://dx.doi.org/10.5252/g2013n3a1
journal article
6405
10.5252/g2013n3a1
9ff37989-fe94-4548-86ca-2b7647a831c1
1638-9395
4538060
Genus
Berabichia
Geyer, 1990
TYPE SPECIES
. —
Berabichia vertumnia
Geyer, 1990
, from the Lemdad Formation (Cambrian Series 2, Sectigena Zone) in the Lemdad Syncline, High Atlas,
Morocco
, OD.
REMARKS
Berabichia
was introduced by
Geyer (1990)
for three species from the Anti-Atlas and High Atlas of
Morocco
, i.e.
B. vertumnia
, the
type
species,
B. stenometopa
Geyer, 1990
and
B. inopinata
Geyer, 1990
, and six additional morphotypes in open nomenclature.
Berabichia inopinata
, differing from most of the remaining Moroccan taxa included in
Berabichia
in a rather homogenous overall convexity of the cephalon (
Geyer 1990
), was subsequently transferred to the genus
Epichalnipsus
Geyer, Popp, Weidner & Förster, 2004
(
Geyer
et al.
2004
). A suggestion was made (
Jell & Adrain 2003: 348
, 436) that
Berabichia
is a junior subjective synonym of
Ptychoparopsis
A
1.1
coefficient
1
allometric
0.9
B C D A1–B B
1.1
coefficient 1
allometric
0.9
0.8
K1 K (J–K1)/2 L
FIG. 9. — Multivariate allometric coefficients for the
Berabichia oratrix
(
Orłowski, 1985
)
dataset:
A
, for sagittal parameters;
B
, for transverse parameters. For each variate, the 95% confidence interval is indicated by a vertical line. The allometric coefficient is shown by a horizontal line within the confidence interval.
Hupé, 1953. However, as pointed out by
Geyer (1990)
,
Ptychoparopsis
is an unrecognizable taxon. Thus,
Berabichia
and
Ptychoparopsis
cannot be synonymized because no direct equalization has ever been proposed (G. Geyer, pers. comm.).
The
Berabichia
group includes also
Chorbusulina wilkesi
Palmer & Gatehouse, 1972
and
Chorbusulina subdita
Palmer & Gatehouse, 1972
from the Lower Cambrian of the
Argentina
Range,
Antarctica
;
Proampyx rotundatus
(
Kiaer, 1917
)
from the Lower Cambrian of
Sweden
; and
Berabichia erratica
Geyer, Popp, Weidner & Förster, 2004
from Pleistocene erratic boulders collected in a gravel pit in northern
Germany
(
Palmer & Gatehouse 1972
;
Geyer 1990
;
Palmer & Rowell 1995
;
Geyer
et al.
2004
).
Geyer (1990: 79)
FIG. 10. — Scatter plot showing the relationship between total glabellar length (B) and fixigenal width at mid-palpebral level [(J−K1)/2] for the
Berabichia oratrix
(
Orłowski,1985
)
dataset;note slight allometry of the sample recording narrowing fixigenae in ontogeny. The exponential function [y = −0.01765x2 + 0.655x + 0.6173] is based on a least-squares criterion and singular value decomposition, with mean and variance standardization for im- proved numerical stability (after
Hammer
et al.
2001
).
FIG. 11. — Scatter plot showing correlation between the B/K ratio and the PC2 values for the
Berabichia oratrix
(
Orłowski, 1985
)
dataset. Black line is the reduced major axis.
FIG. 12. — Biplot of scores and loadings on PC1 and PC2 of the
Berabichia oratrix
(
Orłowski, 1985
)
dataset. PC1 is interpreted as a size axis, PC2 as a width/length difference axis. The lines represent loadings on each parameter. Ellipses mark the area of the 95% confidence interval.
A B 1.5 1 1 0.5 0.5 0 0 -0.5 –0.5 –1 –1 –1.5 -1.5 –1.5 –1 –0.5 0 0.5 1 1.5 –1.5 –1 –0.5 0 0.5 1 1.5 C D 1 1 0.5 0.5 0 0 –0.5 -0.5 –1 –1 –1.5 –1 –0.5 0 0.5 1 1.5 –1.5 –1 –0.5 0 0.5
1 1.5 E
1 0.5 0 –0.5 –1 –1.5 –1 –0.5 0 0.5 1 1.5
FIG. 13. — Scatter plots showing the relationships between principal components for the
Berabichia oratrix
(
Orłowski, 1985
)
dataset:
A
, PC3 and PC4;
B
, PC4 and PC5;
C
, PC5 and PC6;
D
, PC6 and PC7;
E
, PC7 and PC8.Ellipses mark the area of the 95% confidence interval. PC3 to PC8 shown on the plots correspond to morphological variation and are devoid of variation resulting from size (PC1) and width/length difference (PC2).
suggested that
Strenuaeva kiaeri
Samsonowicz, 1959
(
Samsonowicz 1959b
: pl. 1, fig. 16a-c;
Ellipsocephalus kiaeri
of
Orłowski 1985: 239
, textfig. 7, pl. 7, fig. 2) from the
Protolenus-Issafeniella
Zone of the HCM can be tentatively assigned to
Berabichia
; however, the only known speci- men is strongly effaced, has very shallow lateral and axial furrows and might represent a tectonic variant of
Issafeniella orlowinensis
(
Samsonowicz, 1959b
)
from the same interval (see
Żylińska & Masiak 2007
and
Żylińska & Szczepanik 2009
for comparison).