Records of the Western Australian Museum 17: 331-341 (1995). 
Acanthodian dental elements from the Trundle beds (Lower Devonian) 
of New South Wales 
C.J. Burrow 
Department of Zoology, University of Queensland, Queensland 4072 
Abstract - Acanthodian dental elements from the Trundle beds (Lochkovian- 
Pragian) of central New South Wales include dentigerous jaw bone 
fragments, tooth whorls, single teeth, and dentition cones setisu Valiukeviaus. 
Among acanthodians, only members of the Order Ischnacanthida possess an 
equivalent range of dental elements. Comparisons suggest that most of the 
Trundle beds elements belong to an ischnacanthid taxon with close affinity 
to Poracanlhodes. Some other elements, distinctive tooth whorls including a 
type not previously described, possibly belong to a species with dentition 
that matches no known climatiid or ischnacanthid. 
INTRODUCTION 
The Class Acanthodii, as defined by recent 
workers (e.g., Denison 1979; Long 1986), has two 
orders which possessed teeth - the Climatiida and 
the Ischnacanthida. Amongst the climatiids, only 
fish of the family Climatiidae had teeth, comprising 
rows of tooth whorls. The Ischnacanthida are 
distinguished from other acanthodians by 
possessing dentigerous jaw bones, or gnathals, on 
both upper and lower jaws. 
Acanthodian dental elements, including 
dentigerous jaw bone fragments, tooth whorls, 
isolated single teeth and dentition cones (sensu 
Valiukevicfius 1992) occur in shallow water, marine 
limestones from the upper Lochkovian/lower 
Pragian Trundle beds (informal geological name; 
Pickett 1992; Pickett and McClatchie 1991) of 
central New South Wales (Figure 1). Isolated scales 
of at least four acanthodian species (Burrow in 
press) have been reported from these same beds. 
This material comprises rare scales of the climatiid 
Nostolepis striata and Machaeracanthus sp. 
(Acanthodii incertae sedis), and abundant scales of 
a new species (Burrow in press) and "Nostolepis" 
guangxiensis Wang, both of which might be 
ischnacanthids. 
Few systematic descriptions of Australian Early 
Devonian acanthodian microremains have been 
published; Gross (1971a) described a small 
collection of acanthodian scales from Wilson's 
Cliffs, Western Australia, but the paucity and poor 
preservation of the material precluded classifying 
the scales. Long (1986) described small 
ischnacanthid gnathal bones of two types from the 
Emsian Spirifer yassensis and Cavan Bluff 
Limestones, Murrimbidgee Group, near Taemas, 
New South Wales, and from the uppermost Emsian 
Rocky Camp member, Murrindal Limestone, 
Buchan Group of Victoria. He assigned the bones 
to two separate genera, Taemasacanthus and 
Rockycampacanthus (Figure 2A-C) respectively. 
Turner (e.g., 1991) has recorded many occurrences 
of acanthodian scales, and has also reported 
occurrences of dental elements (e.g.. Turner 1991, 
plate 2, fig. D). 
Worldwide, a number of ischnacanthid taxa have 
been described based on isolated dentigerous jaw 
bones; only a small number ( Ischnacanthus gracilis, 
Uraniacanthus spinosus and Poracanthodes menneri) 
are based on descriptions of articulated fish. 
Assigning the gnathal bones to the upper or lower 
jaw is often not possible, as only rarely is the 
posterior end preserved with the dentigerous area. 
Moreover, in the taxa based on articulated 
specimens, the upper and lower dentigerous zones 
are identical. 
The present paper describes the acanthodian 
dental elements found in the Trundle beds 
samples, including two previously undescribed 
elements - a denticulated plate plus toothwhorl, 
and the posterior end of a probable upper jaw 
gnathal. An attempt is made to elucidate the dental 
patterns of the acanthodian fish from which the 
elements derive, and the affinities of these taxa are 
discussed. 
MATERIAL 
The specimens described in this study are from 
limestone samples collected and treated with acetic 
acid by Dr John Pickett (Geological Survey of New 
South Wales), and subsequently picked for 
microvertebrates by Dr Susan Turner (Queensland 
Museum) and the author. The samples are from 
