Art. XLV.—Remarks on Dr: von. Haast's Classification of the Moas.
[Read before the Otago Institute, October 24th, 1876.]
In his Presidential Address to the Philosophical Institute of Canterbury, in March, 1874, Dr. von Haast gives his views as to the proper classification of the Moas, * dividing them into two families, each of which consists of two genera.
The first of these families, Dinornithidœ, is characterised by having no hind toe, by the bill being narrow and pointed, and by the metatarsus being comparatively long. The second family, Palapterygidœ, is characterised by having a hind toe, by the bill being obtuse and rounded at the tip, and by having the metatarsus short. This classification is given as the result of his researches, but, owing no doubt to the nature of the address, no proofs are adduced as to the correctness of his diagnoses, although they directly contradict some of the results of the researches of Professor Owen. Since the publication of this address, a large and very valuable collection of Moa remains has been brought together in the Otago Museum, and an examination of it has compelled me to reject Dr. von Haast's classification, and to agree on almost every point with Professor Owen.
In the first place none of the differences pointed out by Dr. von. Haast are sufficient, in my opinion, to warrant us in dividing the Moas into two families. The skeletons of all the species are remarkably alike. Between no two is there anything like the difference that exists between the skeletons of the Ostrich and the Rhea, which are always considered as belonging to one family. Nor is the difference so great as between the Emu and the Cassowary, which also belong to one family. The presence or absence of a hind toe, even if Dr. von Haast had been correct on this point, is by no means of sufficient importance to be used as a family character, for several families of birds contain genera both with and without hind toes. Neither can the absence or presence of a scapulo-coracoid be deemed of much importance in classification, for it is functionless or nearly so. Dr. Haast, however, uses this as a generic character only. Consequently we must, I think, consider all the Moas as belonging to one family, Dinornithidœ. Whether they should or should not be considered as forming one or more genera is a more difficult question in the present imperfect state of our knowledge of their anatomy. If, however, it should be thought advisable to divide them, many of the characters given by Dr. von Haast cannot be used.
[Footnote] * “Trans. N.Z. Inst.,” Vol. VI., p. 426.
In the collection of Moa remains in the Otago Museum there are five feet, and metatarsi of individual birds, in which the hind toe still remains. Of these two belong to D. ingens, one to D. casuarinus, and two to D. gravis. If to these we add D. robustus, the hind toe of which has been figured by Professor Owen,* we have four species in which the hind toe is known, and of these, three belong to Dr. von Haast's family, Dinornithidœ, one of the distinguishing characters of which is said to be the absence of a hind toe.
Next with regard to the shape of the bill. There is in the Otago Museum a nearly complete skeleton of D. robustus, obtained singly at Highly Hill. In this specimen the bill is exceedingly broad, rounded at the tip and some-what depressed, exactly like that described by Professor Owen,† and Professor Owen has shown‡ that the bill of D. ingens was of the same shape; whereas Dr. von. Haast gives the diagnosis as “beak narrow and pointed.”
Nearly all the Moa bones found at Shag Point belonged to D. casuarinus or D. gravis, but a few to D. erassus. None of the skulls had pointed bills. In the Hamilton Swamp the commonest species were D. elephantopus and D. crassus, and here we found several skulls, all larger than that of D. crassus, with pointed bills, and answering to that described by Professor Owen§ as D. elephantopus.∥ I am therefore inclined to think that Dr. von Haast is wrong in ascribing to D. elephantopus a bill very obtuse and rounded at the tip. At any rate I must think so until Dr. von. Haast publishes the reasons for his opinion. A single small skull with a very pointed bill was found in the Hamilton Swamp. This, from its size, I agree with Dr. von Haast in ascribing to D. didiformis. In D. crassus the bill was obtuse and rounded, but more compressed than in D. robustus. This is proved by a skull and vertebral column from Shag Point, which agrees exactly with the skeleton from the Waitaki in the Otago Museum. I have already pointed out** that it is doubtful whether this skeleton should be referred to D. crassus. D. elephantopus; but since Professor Coughtrey identified the skull of D. elephantopus from the Hamilton Swamp, I am inclined to think that the Waitaki specimen must be D. crassus, and that it can be distinguished from D. elephantopus by the shape of the bill.
The sternum in Dinornis is a very variable bone, and often unsymmetrical. Those in the Museum belonging to robustus, casuarinus, elephantopusm, and crassus agree very well with Dr. von. Haast's remarks. The sterna of D. gravis, however, from Shag Point, are not longer than broad, but resemble
[Footnote] *“Trans. Zool. Soe.,” Vol. IV., p. 1.
[Footnote] † “Trans. Zool. Soe.,” Vol. V., p, 344.
[Footnote] ‡ Loc. cit., Vol. VII., p. 142.
[Footnote] § “Trans. Zool. Soe.,” Vol. VII., p. 123.
[Footnote] ∥ Determined for me by Professor Coughtrey.
[Footnote] ** “Trans. N. Z. Inst.,” Vol, VII., p. 276.
that of D. elephantopus in miniature. Dr. von Haast also gives the existence of two sternal ribs only as a character of elephantopus and crassus; but the Waitakin skeleton, which certainly belongs to one or the other, has three sternal ribs articulating with the sternum on each side, like all the other Moas.
Again, Dr. von Haast has included D. rheides in his genus Euryapteryx, of which he tells us the metatarsi of D. rheides are proportionately longer than those of D. casuarinus or D. didiformis.
It is hardly necessary to remark that no difference in structure, such as Dr. von. Haast supposes to exist between the bones of what he calls Palapterygidœ and Dinornithidœ, can be made out. The differences mentioned by Dr. von. Haast are found among all fossil bones.
It is evident, therefore, that if the Moas are to be divided into two or more genera, Dr. von Haast's classification will have to be modified. His genus Euryapteryx is quite unnecessary, as D. rheides should go with D. didiformis, and D. gravis with D. crassus. If the Moas are to be classed by the relative proportions of their metatarsi, then perhaps the three other genera of Dr. von Haast might stand, but the name Palapteryx must, according to the rules of zoological nomenclature, be given to the ingens group, that of Dinornis to the elephantopus group, while Meiornis will remain for rheides and didiformis; but this appears to be hardly necessary. If, however, the shape of the bill be taken as the more important character, then Palapteryx would remain as before; but elephantopus, rheides, and didiformis would have to be brought into one group, and crassus, casuarinus and gravis into another. On the whole, I am inclined to agree with Professor Owen that one genus is sufficient for our present information.*
[Footnote] * See “Trans. Zool. Soe.,” Vol. VII., p. 145; and Vol. VIII., p. 375.