A review of the brachylepadomorph cirripede genus Pycnolepas, including the first record of an Early Cretaceous species from the Russian Far East *
Author
Jagt, John W. M.
Author
Zonova, Tatiana D.
Author
Jagt-Yazykova, Elena A.
text
Zootaxa
2007
1545
33
47
journal article
10.5281/zenodo.177977
68d70702-9696-4c34-8197-83f16ce26020
1175-5326
177977
Pycnolepas
rigida
(J. de
C. Sowerby, 1836
)
Original description.
J. de
C. Sowerby (1836: 335, pl. 11, fig. 6, as
Pollicipes rigidus
)
.
Type
.
Lectotype
, designated by
Withers (1914: 170)
, is a scutum illustrated by J. de
C. Sowerby (1836)
; current whereabouts unknown.
Locality and stratigraphy.
Folkestone, southeast
England
; lower Gault (middle Albian).
Remarks.
Va l v e s o f
P
.
rigida
are transversely, and generally also longitudinally, ridged; scutum elongatetriangular, with basilateral portion produced and with narrow wall-sided ridge curving from apex to basilateral angle; tergum with apical portion much curved towards scutum and with ridge like that of scutum, curving from apex to basal angle; width of imbricating plates exceeding height. Lot NHMM 2006 0 20 (leg. J.S.H. Collins), comprising isolated scuta, terga, rostra and carinae from the Albian of Bedfordshire (
England
), shows the wide range of variation of this taxon, expressed in valve proportions (length/width ratio), ornament (in particular, number and strength of longitudinal and transverse ribs) and width of apicobasal ridge (see
Withers, 1935
).
Occurrence.
Lower Albian (c. 108–107 Ma) to middle (?upper) Cenomanian (c. 93–92 Ma),
England
(Bedfordshire, Kent, Cambridge area) and
France
(Yonne, Haute-Marne); common in the lower Albian
Leymeriella tardefurcata
Zone
, ranging throughout overlying Albian zones and extending into the Chalk Marl and higher (Cenomanian,
Schloenbachia varians
and
Holaster
[
= Crassiholaster
]
subglobosus
zones) (
Collins, 1980
;
Carriol & Collins, 2000
;
Owen, 2002
;
Smith & Wright, 2003
).