New species and occurrence records of Japanese Solasteridae and Ganeriidae including a new species of Paralophaster from the North Pacific with an overview of Hyalinothrix
Author
Mah, Christopher L.
Author
Fujita, Toshihiko
text
Zootaxa
2020
2020-03-10
4750
1
67
100
journal article
10.11646/zootaxa.4750.1.4
ff300143-3581-4909-ae95-8dec768fe27a
1175-5326
3702847
CF37CEA8-E156-48A6-8A28-C94A294A75DF
Hyalinothrix grangei
(
Clark & McKnight, 2001
)
nov. comb.
Nepanthia grangei
H. E. S.
Clark & McKnight 2001: 159
.
Comments.
A review of diagnostic characters of
Hyalinothrix
versus comparable taxa in the
Asterinidae
indicate that
Nepanthia grangei
Clark & McKnight, 2001
should be re-assigned to the genus
Hyalinothrix
.
Holotype
images and the description of
Nepanthia grangei
showed the specimen with abactinal paxillar plates, described as tabulate, with glassine spinelets, which are absent from the definition of
Nepanthia
(e.g., Rowe & Marsh 1982;
O’Loughlin & Waters 2004
) and nearly all asterinids, which display spines sitting directly on abactinal and other low-lying surface plates.
Nepanthia grangei
was placed into
Pseudonepanthia
by
O’Loughlin & Waters (2004)
, but comparisons of the type species,
Pseudonepanthia gotoi
A. H. Clark 1916
show spines sitting directly on the abactinal plates (
O’Loughlin & Waters 2004
), rather than on elongate tabulate or paxillar plates, as indicated on
Nepanthia grangei
.
If
Nepanthia grangei
is re-assigned to
Hyalinothrix
, this has an significant outcome on the interpretation of molecular phylogenetic results presented in
Mah & Foltz (2011)
. In their trees (
Mah & Foltz 2011
:
Fig. 2
),
Nepanthia grangei
occurs on a well supported branch (93%) with
Tarachaster australis
and implies a sister group relationship between
Nepanthia
and the “paxillate ganeriids” such as
Tarachaster
. This taxonomic change would support
Hyalinothrix
and
Tarachaster
on a single, relatively well-supported branch, separate from
Chaetaster
,
which was supported as sister branch to the
Odontasteridae
.
Hyalinothrix
and
Tarachaster
on a single branch would separate them from the
Ganeriidae
sensu
Spencer and Wright (1966)
and Fisher (1911), which included
Cycethra
,
Perknaster
, and
Cuenotaster
, disputing the historical interpretation of the
Ganeriidae
as monophyletic.