Biostratigraphy of Devonian microvertebrates 
423 
common in Lochkovian to Emsian limestones of 
NSW (Turner 1991); no examples are illustrated. 
The Broken River scales occur in horizons as young 
as Givetian; one specimen is from SD204/120m, in 
upper varcus Zone, dated by presence of conodonts 
Polygnathus varcus, P. latifossatus and P. timorensis. 
Nostolepis sp. 1 
Figures 3J, K 
Material 
1 scale (QMF 31825); other scales possibly belong 
to this taxon but are too abraded to assign with 
certainty. 
Locality 
SD210/196.4 m; Papilio Formation. 
Stratigraphic level 
Givetian (Upper varcus Zone). 
Remarks 
This scale differs from those assigned above to 
Nostolepis cf. costata in crown ornament: a central 
raised section, tapering posteriorly and with 
oblique ridges on the lateral edges, and with a flat, 
broad rim. 
Description 
The diamond-shaped scale is 0.5 mm long and 
wide, and 0.3 mm high. The central part of the 
crown is raised and smooth except for a median 
ridge (Figure 3K); the sloping lateral edges of this 
raised section have several oblique ridges (Figure 
3J). The base is strongly convex. A distinct 
projecting rim encircles the scale at the crown/base 
junction. 
Discussion 
A similar nostolepid scale from the Pragian-early 
Emsian Jauf Formation of Saudi Arabia is figured 
by Boucot ct al. (1989, figure 20a,b). Turner and 
Murphy (1988, figure 2.2) illustrate the crown view 
of a Nostolepis-type scale, which they consider 
resembles scales of N. striata, from the Windmill 
Limestone of the Simpson Park Range, Eureka 
County, Nevada; this scale is similar to the Broken 
River specimen. It is noted, however, that these 
figured scales are from the Early Devonian, 
whereas the Broken River specimen is dated 
Middle Devonian. 
Nostolepis sp. 2 
Figures 3E-G 
Material 
51 scales (QMF 31821,2 + 49 others). 
Localities 
SD170/185-200 m; Bracteata Formation. 
Stratigraphic level 
Emsian (serotinus Zone). 
Description 
These scales have the same diamond shape in 
crown view and deeply convex base as Nostolepis 
sp. 1, and a similar central, raised sloping section 
on the crown. They differ in having the raised 
crown section more triangular with the central 
ridge more pronounced and extending further 
anteriorly (Figure 3E), in the sloping lateral edges 
of the raised section being unornamented, and in 
lacking the protruding rim where the crown joins 
the base. The lateral and posterior corners of the 
crown are slightly extended into points (Figure 3E), 
while the anterior corner is rounded. Scales of this 
type are slightly smaller than Nostolepis sp. 1 - 
length and width are approximately 0.3 mm, and 
height about 0.2 mm. Fifty of the scales were 
recovered from the same sample (185m above base 
of section SD170). It is possible, therefore, that they 
are from a single fish, but preservation is not 
adequate to detect a noticeable variation among 
them, with the exception of the double scale 
illustrated in Figure 3G. 
Discussion 
The Nostolepis-type scale from the Lochkovian of 
Nevada figured by Turner and Murphy (1988, 
figure 2.3) bears a slight resemblance in crown 
view to the Broken River specimens, in the 
tripartite central raised section on the crown and in 
the overall diamond-shaped outline. 
Nostolepis sp. 3 
Figures 3M, N 
Material 
Three scales (QMF 31826 + two others). 
Locality 
SD170/185,710 m; Bracteata Formation, Dosey 
Limestone. 
Stratigraphic range 
Emsian (serotinus Zone) and Eifelian (kockelianus 
Zone). 
Remarks 
These scales differ from those of Nostolepis cf. 
costata discussed above by having a flat crown with 
low subparallel ridges only in the anterior half, in 
contrast to the strong, radiating ridges extending 
to the posterior of the crown in Nostolepis cf. 
costata, and in the lateral rounded projection. They 
