Revision of F. R. C. Reed’s Ordovician trilobite types from Myanmar (Burma) and western Yunnan Province, China
Author
Fortey, Richard A.
Department of Earth Sciences, Museum of Natural History, Cromwell Road, London, SW 7 5 BD, UK.
Author
Wernette, Shelly J.
Department of Earth and Planetary Sciences, University of California, Riverside, CA 92521, USA. & Department of Geography and Environmental Studies, Texas State University, San Marcos, TX 78666, USA
Author
Hughes, Nigel C.
text
Zootaxa
2022
2022-07-08
5162
4
301
356
journal article
93239
10.11646/zootaxa.5162.4.1
7d343017-483e-43be-9439-d06e748fc54e
1175-5326
6810290
DD2279FA-E8F1-4951-A5CA-91082E875580
Phorocephala mansuyi
(
Reed, 1917
)
Figs 15.6-8
1917
Bathyurus mansuyi
sp. nov.
; Reed, p. 50–51, pl. 8, fig. 8.
1975
Phorocephala mansuyi
(Reed)
; Lu, p. 189, 396.
1984
Phorocephala mansuyi
(Reed)
; Zhou, Yin & Tripp, p. 24.
Material.
Holotype
: cranidium from Shihtien Formation (Darriwilian) at Pupiao, Baoshan Prefecture,
Figs 15.6–8
(
Reed, 1917
, pl. 8, fig. 8),
GSI
11848.
Discussion.
The single example of this species is too fragile to cast successfully and we are obliged to re-use Reed’s original (1917) illustration, with the cast showing preglabellar features.
Phorocephala
species
vary with regard to the size of the eyes, though they are always prominent. In
P. mansuyi
the palpebral lobes are of relatively moderate size and posteriorly positioned, and in this regard this species is different from several other large-eyed Chinese species, such as
P. quadrata
Zhou & Dean, 1986
; these last authors also reviewed other species that might be assigned to
Phorocephala
.
Phorocephala mansuyi
was the first of these species to be named and therefore is potentially a senior name for a few other species with moderately-sized palpebral lobes. These include particularly the
type
species,
P. typa
Lu, 1965
, and
P. shizipuensis
Yin
in
Yin & Li (1978)
from
Guizhou Province
(see
Zhou
et al.,
1984
). The former (see
Lu, 1975
, pl. 34, fig. 13) has a slightly wider cranidium than
P. mansuyi
and its preglabellar field is the same width (sag.) as the cranidial border, whereas on
P. mansuyi
the border is certainly narrower than the preglabellar field. One cranidium of
P. shizipuensis
illustrated by
Zhou
et al.
(1984
, fig. 5v) has similar general proportions to the
type
, and only known specimen of
P. mansuyi
, and on this specimen the border also seems to be convex rather than “upturned” (
Zhou
et al.,
1984
, p. 24) as claimed from
P. shizipuensis
. However, the cranidial border does seem to be wider than on
P. mansuyi
on several specimens used to illustrate
P. shizipuensis
by
Zhou
et al.
(1984)
. Since both
P. mansuyi
and
P. typa
are known from only one cranidium apiece there is no way of assessing variation in these species, and the eventual status of
P. mansuyi
will depend on new collections.