Revision of the pentacrinid stalked crinoids of the genus Endoxocrinus (Echinodermata, Crinoidea), with a study of environmental control of characters and its consequences for taxonomy
Author
David, Jerome
Author
Roux, Michel
Author
Messing, Charles G.
Author
Ameziane, Nadia
text
Zootaxa
2006
1156
1
50
journal article
50584
10.5281/zenodo.172265
20ced0ab-42ec-4de6-bab0-b3da6529bae9
11755326
172265
Endoxocrinus
(
Diplocrinus
)
wyvillethomsoni
(
Jeffreys, 1870
)
Figures 17
,
19
b, 20d.
Synonymy:
Pentacrinus
wyvillethomsoni
Jeffreys, 1870
: 157, nomen nudum;
Pentacrinus wyvillethomsoni
Thomson, 1872: 767
;
Pentacrinus
wyvillethomsoni
Carpenter, 1884
: 313;
Isocrinus
wyvillethomsoni
Döderlein, 1907
: 19;
Endoxocrinus
wyvillethomsoni
A.H. Clark, 1908b
: 152;
Pentacrinus
(
Endoxocrinus
)
wyvillethomsoni
Koehler & Vaney, 1910
: 6;
Cenocrinus
(
Diplocrinus
)
wyvillethomsoni
Döderlein, 1912
: 20–21;
Annacrinus
wyvillethomsoni
A.H. Clark, 1923
: 11;
Diplocrinus (Annacrinus) wyvillethomsoni
Roux, 1977
: 64
;
Endoxocrinus
(
Diplocrinus
)
wyvillethomsoni
David, 1998: 202
(unpublished data);
Endoxocrinus (Annacrinus) wyvillethomsoni
Roux et al., 2002
: 820
.
Emended diagnosis
A species of the subgenus
Diplocrinus
with 10 to 21 smooth arms (mode 19) up to
10.5 cm
long (mean
7 cm
); arm branching usually isotomous; nonmuscular articulation Br1+2 intermediate between synostosis and syzygy, showing a general symmorphy, tending to a true synostosis distally and to a syzygy between primibrachials; concave proximal facet of IBr2 with axial canal lumen bilobate and a radial syzygial crenularium at its aboral border; number of internodals per noditaxis 20–56 (mode 32); stalk length strongly variable,
3.5–22.5 cm
(mean usually ~
11 cm
); middle and distal stalk pentagonal to circular in cross section; columnals usually homometric and relatively high; proximalmost diameter of stalk up to
4.2 mm
(mean
2.9 cm
); rudimentary cirri present to 3rd nodal; proximal cirri oriented upward; always 5 robust cirri; symplexies usually with 3 to 5 main crenulae per interpetaloid zone, tending to a radial pattern; cryptosymplexies flat or with slight general symmorphy; syzygial stereom predominating on interpetaloid zones and on a regular outer border of the facet; axial canal filled up by large meshed stereom not clearly separated from perilumen; secondary lumen small or absent.
Type
locality
Off
Portugal
at a depth of
1980 m
.
Lectotype
: Catalogue no. 1885.3.30.19, Natural History Museum, London; we designate as the lectopype the Porcupine specimen which resembles most closely
Figure 1
, Plate 18 (
Carpenter 1884
).
Occurence
Northeastern Atlantic from the northern Bay of Biscay to Madeira and south of the Canary Islands at depths from
1246 m
(possibly
900 m
) to
2070 m
(
Conan et al., 1981
). The species was recently photographed via ROV at
1214 m
in the Bay of Biscay (unpublished data from Vital cruise, courtesy of O. Brosseau,
MNHN
Paris).