Taxonomy and phylogeny of the ‘ football stars’ (Asteroidea, Sphaerasteridae)
Author
Gale, Andrew Scott
School of the Environment, Geography and Geological Sciences, University of Portsmouth, Burnaby Building, Burnaby Road, Portsmouth PO 1 3 QL UK; & Department of Earth Sciences, Natural History Museum, Cromwell Road, London SW 7 5 BD, UK
text
Journal of Systematic Palaeontology
2021
2021-10-01
19
10
691
741
http://dx.doi.org/10.1080/14772019.2021.1960911
journal article
293303
10.1080/14772019.2021.1960911
53749253-12aa-41cc-9eec-e28c0b075738
1478-0941
10949919
F8991F09-B5FB-40EF-B4CC-474D925085B8
Valettaster argus
(
Spencer, 1907
)
(
Figs 6H–K, N, O
,
7P, R
,
8K, M
,
22L
,
23B–P
)
1850 fragment of an
Oreaster
Forbes
in Dixon: pl. 21, fig. 16.
$1907
Stauranderaster argus
Spencer
: 99, pl. 29, fig. 8.
1913
Tholaster argus
(Spencer)
; Spencer: 138, pl 13, fig. 25.
1914
Valettaster ocellatus
(Forbes)
; Valette: 60, fig. 20.
1985
Valettaster argus
(Spencer)
; Breton: 91, fig. 6.
Type.
An
individual (not figured) from the
Marsupites
Zone
of
Brighton
, southern
England
(
NHMUK
E 5109
) is the
holotype
.
Diagnosis.
Valettaster
in which the abactinal ossicles possess small external faces and bear a reticulate sculpture.
Material.
A well-preserved specimen from the
coranguinum
Zone of Micheldever,
Hampshire
(
NHMUK
E 20294) and a partly articulated specimen from the same zone at Thanet,
Kent
, provide many details of the ossicles and nature of the abactinal surface (
NHMUK
EE 17637).
Occurrence.
Valettaster argus
is present in the Turonian to Campanian Chalk of the
United Kingdom
.
Remarks.
The new material provides information on the nature of the exterior surface of this species (
Fig. 23H–K
). The spaces between the large abactinal ossicles are packed with smaller, secondary ossicles of various sizes (
Fig. 23H
), creating a smooth surface made up of the exposed summits of the larger ossicles and the smaller plates (
Fig. 23 I, J
). There are spaces between the smaller ossicles, which might represent papular pores (
Fig. 23J
), or where secondary ossicles have fallen out. It is important to point out that the reconstruction of
Breton (1985
, fig. 4), which shows the surface of the asteroid with a thick dermis, containing numerous small ossicles, is incorrect.