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
bruennichi
Withers, 1914
Original description.
Withers (1914: 181, pl. 7, figs 5–9; pl. 8, fig. 6, as
Pycnolepas brünnichi
)
.
Type
.
Holotype
is NHM I.16625, a right scutum.
Locality and stratigraphy.
Fakse, Sjaelland (eastern
Denmark
); middle Danian (
Tylocidaris bruennichi
Zone
; c. 63 Ma).
Remarks.
Valves of this species are strongly ridged both transversely and longitudinally; scutum subtriangular, with broad wall-sided apicobasal ridge, occasionally broader than tergo-lateral portion, tergum with apical portion only slightly curved towards scutum and a similar, yet much narrower, near-straight apicobasal ridge. Height of imbricating plates exceeding width. On tergum, longitudinal ridges subdued by prominent growth lines. Thousands of isolated, yet associated, valves are known from the middle Danian of Fakse, and allow the species to be reconstructed; however, upper latera invariably are rare. Postulated to have been attached either to certain scleractinian corals and/or logs (
Donovan & Jakobsen, 2004
), substrates now dissolved.
Withers (1914)
proposed
Pycnolepas
bruennichi
as a replacement name for
Pollicipes elegans
Darwin, 1851
(76, pl. 4, fig. 9a–d),
non
Lesson (1830: 441)
, and later (
Withers, 1935
) showed
P
.
bruennichi
to be confined to strata of early Paleocene (Danian) age.
Drygant (1966
: 116, fig. 8a, b) recorded a single carina from upper Maastrichtian levels at Briukhovichi, Volhynia-Podolia (now western
Ukraine
) which he assigned to
Pycnolepas elegans
(Darwin)
. This, however, clearly represents a typical carina of the calanticine
Scillaelepas darwiniana
(
Bosquet, 1854
)
, as already noted by
Alekseev (1979)
.
Occurrence.
Lower and middle Danian of
Denmark
(
Withers, 1914
,
1935
;
Jakobsen, 2003
;
Donovan & Jakobsen, 2004
;
Jakobsen & Feldmann, 2004
), southern
Sweden
(Limhamn area), northeast
Belgium
and the southeast
Netherlands
(
Jagt & Collins, 1988
;
Jagt, 1996
) and the Crimean Peninsula,
Ukraine
(
Alekseev, 1979
).