Notes on New Zealand Cetacea, Recent and Fossil. Neobalœna marginata, Kogia breviceps, Orca gladiator, Balœnoptera and Kekenodon onamata.

Transactions and Proceedings of the Royal Society of New Zealand, Volume 13, 1880, Page 434

2. “Notes on New Zealand Cetacea, Recent and Fossil,” by Dr. Hector. Abstract. Dr. Hector explained that the illustrations of this paper would not be ready for the forthcoming volume. The notes on the recent Cetacea give a detailed description of Neobalœna marginata, two complete skeletons of which (adult and young) are now mounted in the Museum. The presence of 17 pairs of ribs and the permanency of the remarkable characters, afforded by the expanded and lammeller structure of the ribs and vertebral processes, thoroughly establishes the generic independence of this Whale as a form intermediate between the true Baleen Whales and the Rorquals. Kogia breviceps: A cow and calf of this miniature sperm whale, cast ashore at Lyell's Bay, have been secured, and portions of the latter preserved in spirit for future examination. Orca: Two examples of this genus have been obtained; the first ran ashore at Lyell's Bay, and the second, which appears to be a full adult example of Orca gladiator, was cast up on the beach near Wanganui.

Kekenodon Onamata, Hector. Proc. p.436.

Among the fossil Cetacea referred to is a skull of a whale, closely allied to Balæn-optera, from the middle miocene formation on the West Coast of the South Island. The matrix which encloses this fossil, is so hard that it is as yet only imperfectly displayed, but it comprises the occipital parietal and frontal bones. The teeth and bone fragments of a Zenglodont—recently determined from a collection of fossils made by Mr. McKay, during the progress of the Geological Survey in the present season—forms an interesting addition to New Zealand Palæontology. Unfortunately the form of the skull cannot be determined, but the crowns of the teeth agree with that of the great American fossil. They were obtained from the upper eocene strata of the Waitaki valley, in Otago. Fragments of the lower jaw and some ten teeth are preserved, but only a few of the latter are perfect. The teeth are of two kinds, incisors and molars. The largest incisors, probably occupying the position of canines, are 6 inches in length, with a dilated and irregularly curved solid fang supporting a sharp-pointed conical crown 1½ inches in length, and covered with a brown polished enamel having, a fluted surface, and two well marked ridges, so that the section of the tooth presents the same pointed elliptical form as in Mososaurus or Liodon. If only the detatched conical crowns of these teeth had been obtained they might have been referred to such a reptilian type. The molars are from 4 to 5 inches in length, and have compressed conical crowns 1½ inches wide, also covered with polished and fluted enamel, and having the cutting edges serrated by eight obtuse bluntly conical lobes. The crowns are supported on powerful fangs, which are, in some cases, distinctly double-rooted, although the roots are closely appressed, except at the extremities. In one tooth—the smallest and probably the anterior molar—the division of the fangs is only indicated by shallow grooves on the inner and outer surfaces, and it has a somewhat trilobate character, while in another, probably the most posterior, the fang is strongly curved. In this last case the crown of the tooth is triangular in section, and has its cutting edge directed obliquely inwards and forwards. All the teeth are solid, or have only a slight excavation at the points of the fangs, and consist of a lamminated cement layer £35 inches in thickness, enclosing the massive dentine. The fragments of bone indicate a massive solid jaw, one portion showing the posterior part of the ramus as having a depth of 6 or 7 inches. One tympanic bulla was obtained. It has the sub-convolute form characteristic of toothed Cetaceans, such as Berardius or Ziphius. The arrangement and number of the teeth cannot be ascertained owing to the imperfect state of the fossil remains, but the general appearance suggests that this huge animal was allied to the earless seals with serrated molars, such as Stenorhynchus, rather than to Cetaceans, but this indication is contradicted by the teeth being solid and by the character of the tympanic bulla. The resemblance to the Zeuglodon is found in the serrated crowns of the double-fanged Molars, but the fangs are not so widely separated, nor do the crowns of the teeth show the hour-glass form in transverse section to the same degree as in the gigantic Zeuglodon, with which it is provisionally associated under the name of Kekenodon onamata* Kekeno (Maori), a seal. Onamata (Maori), of long ago. Note.—Since the foregoing was written I find that a very similar tooth fragment, from the eocene strata of South Australia, has been figured by Mr. E. B. Sanger, as Zeuglodon harwoodii.† Proceedings Linn. Soc. N. S. W., Vol. V. p. 298, 1881.—Also that the New Zealand teeth resemble those figured by Gervais and Van Beneden, as the Phocodon, from Saint Medard-en-Jalle, Bordeaux,‡ Ostéographie des Cétoacés, p. 453. and the

Squalodon, from Dinan, Brittany,* l. c. p. 437, Pl, xxviii. f. 19. but as these generic names and also Zenglodon, appear each to have been applied to several very distinct animals, I deem it advisable to retain the name Kekenodon for the New Zealand fossil. On Plate XVIII., I figure the best preserved portions of this interesting fossil, of the natural size. It will be seen that the molar teeth have not the widely divergent and separately implanted fangs of the Zenglodon of Owen, while the enormous development of the fangs in proportion to the crowns of the teeth, at once distinguish them from the genus Phocodon of Agassiz, established on the Maltese fossil described by Scilla, in 1652, but which partly on account of this short-fanged character of the teeth, was referred by Owen to Hippopotamus.† Odontography, p. 565.