Biostratigraphy of Devonian microvertebrates 
433 
as found in the Broken River specimens (Figures 
5F, G). Similar specimens are currently emerging 
from acid-leaching of material from Fish Hill, a 
limestone outcrop approximately 10 km northeast 
of SD216 (S. Turner, pers. comm.). 
Onychodus sp. has been reported from the Early 
to Late Devonian of Australia, North America, 
Europe and the Middle East (Wells 1944; Blieck et 
al. 1980; Giffin 1980; Vieth-Schreiner 1983; Lelievre 
et al. 1988; Turner and Murphy 1988). The 
distinctive conical, finely striated teeth of 
onychodontids are common in Australian 
microvertebrate residues throughout tire Devonian 
(S. Turner, pers. comm.). 
Infraclass Dipnoi Muller 1844 
?Dipnoan indet. 
Figures 50, P 
Material 
One probable dipnoan toothplate (QMF 31845). 
Locality 
SD131/117.7 m; Papilio Formation. 
Stratigraphic level 
Givetian (Middle varcus Zone). 
Description 
The specimen is about 1.5 mm long, and has 
radiating rows of rounded conical denticles that 
increase in size towards the outer edge of the plate. 
The anterior edge of the fragment (to the bottom in 
Figure 50) has closely-packed, smaller denticles. 
The underside is slightly concave, unornamented, 
and appears to be slightly rougher in texture than 
the smooth denticles. Possibly the specimen has 
split from the underlying bone along a basal pulp 
cavity, so that the base of the toothplate is missing. 
Discussion 
Three types of lungfish are known from Fish Hill 
at Broken River, approximately 10 km northeast of 
the present study area (S. Turner, pers. comm.). 
Cosmine scales 
Figures 5H-J 
Material 
Six scales or fragments (QMF 31840-2 and three 
others). 
Localities 
SD15/145.6-148.5 m, SD170/483 m, SD204/120 
m, SD210/87.7 m, SD216/48.5 m; Papilio 
Formation, Lomandra and Spanner limestones. 
Stratigraphic range 
Eifelian (costatus Zone) and Givetian (Middle 
varcus Zone). 
Remarks 
Cosmine, a hard tissue composed of enamel plus 
dentine and perforated by pores, formed the 
surface layer of scales of Devonian 
crossopterygians and dipnoans. 
Description 
The scales have a shiny, coarsely porous surface 
layer. The pores are of similar size, fairly closely- 
packed, and regularly arranged (Figures 5H, I). The 
pores may open obliquely within semi-elliptical 
depressions (e.g. Figures 51, J), or directly to the 
surface (Figure 5H). 
Discussion 
One scale (Figure 5H) has a square bse with a 
deep, wide groove running across the scale, and is 
much deeper than the others. It resembles 
lepidotrichia of the dipnoan Dipterus described and 
illustrated by Campbell and Barwick (1988, figures 
29C, 30, 31A, B, C). 
The semi-elliptical depressions in the cosmine 
have been illustrated in porolepiform rhipidistians 
(e.g. Schultze 1977, plate 13, figure la) but are 
absent in dipnoans, although this distinction may 
not be apparent in Early Devonian forms (V. 
Karatajute-Talimaa, pers. comm., 1994; E. Mark- 
Kurik, pers. comm., 1994). This generalisation may 
not apply in all cases, however, since 
porolepiforms and dipnoans are closely related 
(Chang and Smith 1992). 
Infraclass Actinopterygii 
Order Palaeonisciformes Hay, 1929 
Palaeoniscoid indet. 
Figures 6A, C-F 
Material 
One scale (QMF 31846) and 34 tooth-bearing 
plates (QMF 31848-51 and 30 others). 
Localities 
QMF 31836: SD192/60 m; Stanley Limestone. 
QMF 31848-51: SD15/148.5 m, SD128/78.2-196.6 
m, SD130/73.6-143 m, SD131/92.1 m, SD204/95- 
120 m, SD210/87.7 m, SD216/30.3 m and SAG/ 
117.7 m; Papilio Formation, Spanner and 
Chinaman Creek limestones. 
Stratigraphic range 
QMF 31836: Earliest Frasnian (asymmetricus 
Zone). 
