Vol. LVII., No. 2. 
7 
A MARINE EARLY CRETACEOUS FAUNA 
FROM STANWELL ( ROCKHAMPTON 
DISTRICT). 
By F. W. Whitehouse, Ph.D., D.Sc. (Lt.-Col., R.A.E.). 
Department of Geology, University of Queensland. 
Received March 12th, 1945; tabled before the Society 21th August, 1945; 
issued separately, 9th October, 1946. 
(Plate 1). 
Summary . — A small molluscan fauna of early Cretaceous age is described from 
a bed at Stanwell that apparently is within the Stanwell Coal Measures. The fauna 
is typical of the Valanginian (?) Trigonia beds of the Indo-Pacifie region and, with 
other evidence, makes the Lower Cretaceous history of Eastern Australia closely 
parallel with that of India and of East and South Africa. From this evidence it 
would appear that the Stanwell Coal Measures may be later than has been thought 
— equivalent to the Blythesdale (pre-Aptian Cretaceous) and not Walloon (mid to 
late Jurassic) Series. This is not at variance with the floral evidence. 
Some years ago Mr. J. H. Reid, District Geologist for Central 
Queensland, discovered marine mollusca on Portions 128 and 129, 
Parish of Stanwell, a locality about 20 miles W.S.W. of Rockhampton. 
There were many fragments, but few good specimens, preserved in a 
hard, brownish, calcareous sandstone. 
Quite apart from its local importance in being evidence of marine 
Cretaceous conditions in a region far removed from other such beds, 
the collection is of unusual general interest in being the first record 
in Australia of a fauna, widespread in Indo-Pacific regions, that has 
given rise in recent times to a considerable controversy. Three questions 
arise : What precisely is the age of the fauna ; how are the beds related 
locally to other sedimentary series; and what are the general palaeo- 
geographical and stratigraphical relations to the Indo-Pacific region at 
large ? 
THE AGE OF THE FAUNA. 
The decisive elements of the fauna are Iotrigonia limatula and 
Pisotrigonia sp. These are members of a fauna rich in peculiar 
Trigonias, that occurs only in the Indo-Pacific region. The trigoniid 
genera have not been recognised in Europe. The Pisotrigonia at this 
locality, although it has been collected only in fragments, is quite typical. 
Trigonias with V-shaped ribbing, as is noted below, appear at several 
horizons in the Jurassic and Cretaceous; but the type of V-ribbing in 
7. limatula is not known in any group other than that of Iotrigonia. 
Other features of the test agree, so that this assemblage may be correlated 
confidently with the Iotrigonia and Pisotrigonia faunas of the Uitenhage 
and Oomia beds. 
The other elements of the fauna, although giving no precise evidence 
of age, are of groups that are found or may be found in those faunas. 
Pseudomonotis and Hibolites begin well down in the Jurassic and last 
until the Aptian. Panope is essentially Cretaceous ; but it is very similar 
to Jurassic and Cretaceous Pleuromya and details of the hinge that 
distinguish the two genera are not shown in these specimens. Indotri- 
gonia is another element of the Iotrigonia faunas in Kachh and East 
C 
