Extinct Birds Part 51

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PALAEOCASUARIUS FORBES.

Dr. Forbes founded this genus of _Dinornithidae_ on remains of Moas of three distinct sizes as regards femora collected by him at Manitoto. Dr.

Forbes has kindly placed these bones at my disposal, and the following summarises the results of my examination. I find that Dr. Forbes' original idea as to the distinctness of _Palaeocasuarius_ is perfectly justified, as not only are his characters of the tibio-tarsus, as opposed to those in the other genera, correct, but the proportions between femur, tibio-tarsus and tarso-metatarsus are quite different to those of other genera. I give the proportions of the three bones in _Palaeocasuarius elegans_, _Megalapteryx tenuipes_, and _Pachyornis elephantopus_, which are the three most nearly allied genera:

------------------------+---------------+--------------+--------------- Pal. elegans. M. tenuipes. Pach.

elephantopus.

------------------------+---------------+--------------+--------------- Femur, length 10-5/8 inches 11 inches 12 inches Width over condyles 3-1/2 " 3-1/2 " 5 "

Tibio-tarsus, length 16 " 15-1/2 " 33 "

Width at distal end 2 " 2-1/4 " 3-1/2 "

Tarso-metatarsus, length 7 " 6 " 9 "

Width at centre 1-1/2 " 1-1/4 " 2-1/4 "

The original diagnosis was as follows, being founded on the tibio-tarsus: "The tibio-tarsus differs from that of all other genera in being straighter and less twisted on itself, so that the position of the ridge forming the inner wall of the groove for the tendons of the extensor muscles run along the inner side of the bone as in _Casuarius_. As in the latter genus it takes a marked turn inwards and backwards before joining the epicnemial crest, while a line joining the centre point between the distal condyles and the epicnemial ridge leaves a considerable s.p.a.ce between it and the wall of the groove. There is no intercondylar eminence in the intercondylar channel, and the orifice of the extensor foramen opens more longitudinally than in the other genera, and points downwards."

Type of the genus: _Palaeocasuarius haasti_ Forbes.

Number of species: 3.

In the following descriptions of the three species I only rely on the measurements of the femora, as not all the other leg bones of the three species are available. {220}

PALAEOCASUARIUS HAASTI FORBES.

_Palaeocasuarius haasti_ Forbes, Trans. N.Z. Inst. XXIV, p. 189 (1892).

Femur: length approximately 8.5 inches; width across head and great trochanter 2.25 inches. Tarso-metatarsus: length 7 inches; width in centre 1.15 inches, at distal end 2.75 inches.

Type from Manitoto in Liverpool Museum.

This bird exceeded considerably the ca.s.sowary in size, is all the author tells us of this bird. It is a pity that Dr. Forbes did not insist on the publication in full of his paper, as proper descriptions of all the twelve new species are wanting.

Habitat: New Zealand.

PALAEOCASUARIUS VELOX FORBES.

_Palaeocasuarius velox_ Forbes, Trans. N.Z. Inst. XXIV, p. 189 (1892).

Femur: length 9.5 inches; width across head and trochanter 2.75 inches, across distal end 2.5 inches. Tarso-metatarsus: length 7 inches; width in centre 1.5 inches, across distal end 3 inches.

Type specimen from Manitoto in Liverpool Museum.

Habitat: New Zealand.

PALAEOCASUARIUS ELEGANS FORBES.

_Palaeocasuarius elegans_ Forbes, Trans. N.Z. Inst. XXIV, p. 189 (1892).

Femur: length 10.75 inches; width across head and trochanter 3.25 inches, across distal end 3.4 inches. Tarso-metatarsus: length 7.8 inches, width over centre 1.75, over distal end about 3.3 inches.

Type specimen from Manitoto in the Liverpool Museum.

Habitat: New Zealand.

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AEPYORNITHIDAE.

The first notice we have from a scientific man of the existence on Madagascar of large Struthious birds is the description by Isidore Geoffroy-Saint-Hilaire of two eggs and a few osseous remains, in the Annales des Sciences naturelles III, Zoologie, vol. XIV (1850). These important objects were sent to the describer by a colonist of Reunion, Monsieur de Malavois, but were obtained from the natives in Madagascar by Captain M. Abadie. A third egg arrived smashed. The name given on this evidence was _Aepyornis maximus_.

Since then some 40 eggs at least and a large number of odd bones have been collected by Monsieur Grandidier, Messrs. Last and others, and Dr. Forsyth Major, but only one practically complete, and one less complete skeleton of a smaller species, named _Aepyornis hildebrandti_ by Dr. Burckhardt.

A large number of species has been diagnosed on the evidence of these bones and eggs by Professor Milne-Edwards, Mr. Dawson Rowley and Mr. Andrews, and a second genus, _Mullerornis_, established.

The following is the diagnosis of the family

AEPYORNITHIDAE.

Head less flattened than in the _Dinornithidae_, much longer and narrower.

Brain case much greater in volume. Occipital condyle strongly pedunculate.

Temporal fossae deep and narrow. The basisphenoid has on each side a well marked pterygoidal apophysis. The lower mandible is straight and stout, recalling somewhat that of _Rhea_, but the maxillary branches are higher and stouter. The symphysis is long, contracted, and hollowed out in the shape of a ladle. The sternum presents many affinities to that of _Apteryx_. It is a thin plastron, flattened, and much widened. The coracoidal articular surfaces similar to those of _Apteryx_. The Coraco-scapulars are feeble, and have so faint an articular surface that the humerus must have been rudimentary. Hallux absent, outer digit has five, the middle digit four, and the inner digit three phalanges.

There are three genera and twelve species.

A striking character is that in the genus _Aepyornis_ the proximal extremity of the tarso-metatarsus is larger than the distal extremity, a feature not found in the majority of other birds.

Monsieur Grandidier has expressly pointed out that _Aepyornis_ had only three toes, I cannot, therefore, understand why Messrs. Lydekker and Evans both state that the hallux is present. {222}

In spite of the researches of Messrs. Grandidier, Last, and Forsyth Major and the large collections sent home by them, the number of _Aepyornis_ bones is infinitesimal compared with the vast ma.s.ses of bones of the _Dinornithidae_ contained in the museums. This paucity of material quite prohibits us from making a critical study of the described species, so that we are at present unable to say if too many or too few species have been diagnosed. I am inclined, however, to think that if we ever get complete skeletons of the larger forms, _Ae. grandidieri_ and _Ae. cursor_ will prove to be s.e.xes of one species, and also _Ae. t.i.tan_ and _Ae. maximus_.

For the present, however, the measurements are too different to allow of their being united without further investigation.

The three genera are as follows:--

AEPYORNIS T. GEOFF.

_Aepyornis_ Geoffroy Saint Hilaire.

_Epiornis_ Geoffroy Saint Hilaire.