September 26, 1907] 



NA TURE 



543 



LETTERS TO THE EDITOR. 



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 expressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of Nature. 

 No notice is taken of anonymous communications.] 



Reconstruction of Diprotodon from the Callabonna 

 Deposits, South Australia. 



So.ME years ago, under dates June 21 and June 28, 1894, 

 Nature contained a notice of an extensive deposit, at Lal« 

 Callabonna. Soutii .'\ustralia, of fossil bones of Diprotodon, 

 Phascolonus, various species of e.\tinct kangaroos, and of 

 a large struthious bird, since named Genyornis newtoni, 

 in honour of the late lamented Prof. Newton, of Cam- 

 bridge, and in recognition of much personal kindness re- 

 ceived from him by the writer. Since that date various 

 and more detailed references to some of the forms repre- 

 sented in this deposit have appeared in the Transactions 

 ■and Memoirs of the Royal Society of South Australia ; 

 and now, at last, after a lapse of years, which may have 

 seemed unnecessarily long to those unacquainted with all 

 the circumstances of the case, we have lately com- 

 pleted at this museum a complete cast in plaster of the 

 skeleton of Diprotodon australis. 

 Some of your readers may be interested 

 in the photograph of this cast which 

 I now send you (Fig. i), as well as in 

 one which gives our idea of the re- 

 construction in the flesh of this mar- 

 supial (Fig. 2). 



As has been previously mentioned in 

 your columns and in the other publi- 

 cation referred to, the state in which 

 the Callabonna fossils were originally 

 found, and the injury which they 

 suffered as the result of a long journey 

 on camel back to the railway line, 

 were such as to require the expendi- 

 ture upon them of much detailed pre- 

 paratory labour before they could be 

 restored to a sound and enduring con- 

 dition ; but while the ultimate result 

 has been quite satisfactory as regards 

 the appendicular skeleton, there have 

 been much greater difficulties, and not 

 so completely a satisfactory result, in 

 respect to the skull and vertebral 

 column. In both these categories the 

 bones were to a degree above all the 

 others soft, friable, broken, and in- 

 filtrated with saline matter that was 

 difficult to ren>ove. In the skulls 

 particularly, the constituent bones ^-^ 



were both broken and greatly dis- 

 torted. Those that had been found 

 lying on their sides were laterally compressed to an 

 extent that the whole cranial mass formed a flattened 

 slab which in some instances did not exceed a few 

 inches in thickness. In other cases the compression had 

 occurred in a dorso-ventral direction with a like result 

 of producing many fractures and much distortion of the 

 proper relation of parts. Fortunately, the distortion has 

 not affected every skull in the same way, so that in the 

 construction of the cast it has been possible to utilise un- 

 disturbed parts of different skulls. 



Nevertheless, even with the considerable mass of 

 material available, both from Callabonna and from other 

 localities, there were some parts of the skull which were 

 never found in an intact condition, and it is in these re- 

 spects that the cast is not to our satisfaction. 



For the information of those who will, it is hoped, ' 

 eventually possess a copy of this cast, it may be well now 1 

 to mention those parts the correctness of which we cannot, 

 imfortunately, for the above reasons guarantee. Coming 

 under this category are the occipital region, with the 

 exception of the condyles and the immediate boundaries 

 of the neural foramen. In not a single skull from Calla- 

 bonna or from elsewhere was this extensive region without 

 such serious breakage and distortion as to render a 



faithful reproduction of its details impossible. Conse- 

 quently, in our restoration we have followed as best we 

 could the details of Owen's figure (Owen's " Fossil 

 Mammals of Australia," Plate xix.. Fig. 3). Then another 

 part that was always greatly damaged was the anterior 

 or malar pier of the zygomatic arch, the broken parts 

 being generally telescoped ; thus we are not quite satisfied 

 that w-e have got this region as it should be, though in 

 other respects the zygoma is correct. Also, as might be 

 expected, the thin laminar edges of the lateral boundaries 

 of the mesopterygoid fossa were always broken, so that 

 we have been consequently devoid of objective guidance in 

 their reconstruction. 



For the vertebrae, many of which were also in a par- 

 ticularly fragmentary and friable condition, a set belong- 

 ing to one animal which was numerically nearly complete 

 was used as models. Where parts of these were deficient, 

 as often occurred, they could generally be supplied by the 

 corresponding segment from another animal, but not 

 always so. We had no model for the neural spines of the 

 sixth and seventh cervical vertebra?, which are thus parts 

 added in conformity with what we conceive to be the 

 serial plan of arrangement. Fourteen vertebrae bear ribs, 

 and there are five of the lumbar series ; four are fused to 

 form the sacral mass, and there are nineteen separate 



NO. 1978, VOL. 76] 



segments in the tail. The ribs, with one exception, are 

 those belonging to the vertebra;, but as most of them 

 were considerably twisted or otherwise distorted, it was 

 sometimes necessary that they should undergo the oper- 

 ation known to wheelwrights as " cutting and shutting " 

 before they could be set properly both to their respective 

 vertebra; and to one another. 



As previously stated, the limb bones, from their fewer 

 fractures and better texture, gave much less trouble in 

 their restoration than those of the axial skeleton. Most 

 of them belong to the same individual as the vertebrfe, 

 but some, in a damaged condition, have been replaced by 

 other bones of suitable size. The peculiar feet, the struc- 

 ture of which was revealed by the Callabonna discovery, 

 have been described (Memoirs Royal Society of South 

 Australia, vol. i., part i.). 



It is clear bv reference to the bones of other skeletons 

 in the Callabonna collection that the animal now repre- 

 sented was of medium size only, the height of the cast at 

 the shoulder being 5 feet 6 inches, but unfortunately the 

 skeletons of the very large individuals were much more in- 

 complete than that which served as our model. I think it 

 would be safe to place the height of the largest animals 

 in life at 6 feet, or perhaps even a few inches more. 



