90 
J. V. NEIL 
Fig. 2. A-B, Miracythere sp. A. A, drawing of LV in¬ 
terior showing muscle scars. B, drawing of LV hinge 
line (not to scale). C, ?Miracythere sp., drawing of RV 
exterior, from Wanganui Series (Castlecliffian, Pleis¬ 
tocene), Wanganui, New Zealand. Scale bars = 0.1 
mm. 
longed to a male or to a female. The juvenile 
specimen (now lost) was close to the adult in lat¬ 
eral dimensions but was much less inflated, sug¬ 
gesting that in the final growth stage or stages 
there was little change in length or height but an 
increase in width. However, Swanson (1979a) 
figured a specimen of M. novaspecta that he con¬ 
sidered to be a juvenile, though its length and 
height are virtually the same as those of the holo- 
type and its width is actually greater. 
The hinge structure of Miracythere sp. A is 
closer to the typical bythocytherid form than to 
that of the type species. In the latter, the left 
valve anterior groove or socket of the hinge ele¬ 
ments extends above the dorsal line established 
by the median bar, and marks the anterodorsal 
angle in pronounced fashion (Fig. 3D). Mira¬ 
cythere sp. A has a narrow anterior groove which 
continues the line of the median bar, parallelling 
the broadly rounded anterodorsal angle (Fig. 
3C). The left valve posterior hinge element of M. 
novaspecta consists of a narrow tooth below, 
with a groove or socket above at the posterodor- 
sal angle. Miracythere sp. A has a groove (in a 
more elongate form), no tooth and a less marked 
posterodorsal angle (Fig. 3C). The Victorian and 
Late Eocene South Australian specimens have a 
lophodont hinge structure. Given that the vari¬ 
ation in hinge structure is a relatively minor one, 
the specimens should be retained in Mira¬ 
cythere. 
As with the genera Puncia and Mariam 
erected by Hornibrook (1949), morphological 
parallels may be drawn between Miracythere 
and some Palaeozoic genera. Ruggieri & Siveter 
(1975) figured a species of Kelletina, K. carnica , 
in which there is ventrally a broad flat platform 
or flange with marginal spines, some of which 
are linked to form a perforated ridge. Kelletina 
carnica also has a lophodont hinge structure very 
similar to that of Miracythere sp. A. The right 
valve of K. carnica has a simple tooth at each of 
the anterodorsal and posterodorsal angles to 
match the grooves in the left valve. The 
unknown right valve of Miracythere sp. A is 
likely also to have such teeth. A further simi¬ 
larity with Palaeozoic genera lies in the muscle 
scar pattern, which in both Miracythere and 
Promanawa McKenzie & Neil, 1983 includes 
prominent dorsal antennal/mandibular scars. 
Morphological similarities with Palaeozoic 
forms gave rise to speculation about the phy¬ 
togeny of the Punciidae by Hornibrook (1949, 
1963), even though at that time no Mesozoic 
representatives of the family were known. 
Herrig (1988), however, has recently discovered 
species of all three punciid genera, Puncia, 
Manawa and Promanawa , in silicified chalky 
limestone of late Maastrichtian age. Swanson 
(1991) made an intensive study of the soft part 
anatomy of punciids, as well as their carapace 
morphology, and concluded that “On the basis 
of a detailed comparison of a number of key 
carapace characters ... punciid ostracods are the 
only living representatives of the predominantly 
