Tasmacetus shepherai. History and Description of Specimens Cast Ashore on Mason's Bay, Stewart Island, in February, 1933.

Transactions and Proceedings of the Royal Society of New Zealand, Volume 70, 1940-41, Page 200

Tasmacetus shepherai. History and Description of Specimens Cast Ashore on Mason's Bay, Stewart Island, in February, 1933. By J. H. Sorensen [Read before the Southland Branch, July 10, 1940; received by the Editor, July 18, 1940; issued separately, December, 1940.] Whilst I was on a holiday visit to Stewart Island in March of 1939, Mr. A. W. Traill,. who resides there, told me of a strange whale which had been stranded on the beach at Mason's Bay in February of 1933. Mr Traill is a keen observer and recognised that this whale was somewhat different from the cetaceans usually washed ashore in this locality. He wrote a description of the specimen and also had the forethought to take measurements. Fortunately, too, Mrs. John Harrison was present with a camera and took an excellent picture which is, so far as I am aware, the only photograph of this species known. The actual finder of the whale was Mr. Geo. Leask and he immediately communicated news of the find to Mr. Traill. Together they visited the animal and proceeded to try to remove the teeth. Finding it hard work with only sheath knives to work with, they ceased work and decided to pay a visit the next day armed with more suitable tools. They both recognised the whale as being strange and hoped to save the entire skeleton for museum purposes. Most unfortunately a heavy gale sprang up during the night, and, on their returning in the morning, they found that the whale had been washed out to sea. Some time later part of the carcase came ashore again, but, as the head was missing, they lost all interest in it. The carcase went to sea again and, some days later still, the head came ashore. It was secured and taken to the sandhills to rot and bleach, but the rest of the carcase was seen no more. A few days after the arrival of this whale on Mason's Bay, Mr. Leask and a Mr. Donaldson found a similar whale on a small beach six miles further south. It resembled the first specimen in every detail, but was proportionately larger and longer. Having the first whale fresh in his memory, Mr. Leask was able to compare the two thoroughly, and has noted that the dentition was similar. This second specimen was later battered to pieces by heavy seas. The descriptions given by Messrs. Leask and Traill agree in all respects and they have stated that both. whales were males. Several years later, the skull of the first specimen was taken by launch to Leask's Bay on Stewart Island when Messrs. Traill and Leask brought round their wool clip. Here the skull remained, Mr Traill hoping that some day some person would come along and be able to identify it. I compared Mr. Traill's notes and measurements with the descriptions of most of the known species but could not make it

agree with any of them. Mr. Traill and I then went to Leask's Bay to view the skull, but it had been removed from its usual resting-place and I only located it by accident. Some person had thrown it off the end of the small wharf and it was lying in some ten feet of water. It was secured with a long boat-hook and Mr. Traill kindly presented it, together with four teeth which he had saved, to the Southland Museum. I took it to Invercargill when I returned to the mainland some days later. At the request of the Press I made a statement that this skull did not agree with any known species, but I was wrong in this statement for, after reading Dr. Oliver's paper on Tasmacetus shepherdi, and checking over his photographs, I was able to identify it as belonging to the same genus and indeed to the same species. The type specimen in the Wanganui Museum, described by Oliver, came ashore some eight months later than the Stewart Island specimen. It seems to have had a somewhat similar history, for it is stated that it too was washed to sea again after the first stranding, and only returned to the shore one month later. It had been partly flensed, was in an advanced stage of decomposition, and one flipper had dropped off. This did not deter Mr. Shepherd, Curator of the Wanganui Museum, for he and his assistants worked at it until every bone and tooth present were saved. Subsequent to the recovery of the Wanganui specimen, a mandible belonging to a whale of the same species was presented to the Dominion Museum, Wellington, by Lady Kinsey, of Christchurch. This mandible was without locality or data. External Characters. The Wanganui specimen was partly flensed and very much decayed, and, as Oliver says in his paper, “The state of a whale carcase a month old may be imagined.” Hitherto the only description given of the external characters of this species is that which appeared in the “Hawera Star” on November 9, 1933, and the brief one given by Oliver in his paper. The “Hawera Star” report is as follows: “The head had a distinctive bulbous appearance due to the presence of blubber in front of the forehead. The eye was fairly large and conspicuous and the skin black on the back striped with greyish-yellow on the flanks and white underneath.” The following description of the Stewart Island specimen is based on the observations and notes of Messrs. Traill and Leask. Measurements of the Wanganui specimen as given by Oliver are given in parentheses. The sketches are from rough drawings made by Mr. Traill, but no attempt is made to draw them to scale. The first specimen noted at Mason's Bay was a male and had an overall length of 23 feet. (20 ft.) (The second specimen measured by Mr Leask was 30 feet in length.) The colouration was bluish-black on the upper surface and bluish-grey on the underparts, the line dividing the colours being very distinct. The dorsal fin was falcate and situated 8 feet from the tip of the flukes. The flippers were small and situated well underneath the body, 18 inches long (17½), and situated 6 feet back from the snout. (Oliver gives

Fig. 1.—Sketch showing external characters. the flipper as being more or less falcate.) The flukes were five feet wide and turned back at the ends. The jaws were long and narrow, the lower mandible extending 1 inch (1½) in advance of the upper. Snout to gape measured 24 inches (26). On the throat were two crescentic grooves each 15 inches in length. The whale had 18 small, uneven, exposed teeth in each side of both upper and lower jaws. The teeth at theend of the lower jaw had bulbous bases contracting steeply to conical crowns. All teeth showed considerable wear. (From the Wanganui specimen 56 teeth were collected, but according to the alveoli the total number of teeth would be 93.) In checking over my MS. and sketches I noted that Mr. Traill's sketch did not show the flukes bilobate. Wishing to make sure that this character did not exist in Tasmacetus shepherdi, I immediately communicated with Mr. Traill. This is his reply:— “I am afraid I cannot definitely say whether there was a middle indentation or not in the flukes of the whale. I remember spreading the flukes out carefully to get the correct shape. If there was one, it must have been very small, and I think I would have noticed it and taken note of it otherwise.” I also wrote to the Wanganui Museum asking if the sex had been noted of the type specimen. The Hon. Director, Mr. J. Grant, replied as follows:— “Re the whale: The Tasmacetus was in too rotten a condition for Shepherd to determine the sex, but the Maoris who took most of the blubber before the whale was taken to sea the second time assured him that they found the young one inside. It was also impossible to determine whether throat grooves were present ….”

Tasmaclus shoph Oliver Cast ashore on Mason's Bay.

Fig. 1—Lateral teeth (3) and one terminal tooth showing bulbous base. Fig. 2—Ventral view of skull.

Cranial Measurements. The following measurements are from the Mason's Bay specimen now in the Southland Museum. They are compared with those given by Oliver of the Wanganui type specimen in his paper. (Pages 373 to 376.) Oliver's measurements are again given in parentheses. Width of rostrum at the point where it begins to widen quickly (the anterior edge of the pterygoids) 210 mm. (173) Depth 145 mm. (130) Greatest width across the nasals Right 52 99 mm. (R. 48) Left 47 (90—L. 42) Nasals from the top of the mesethmoid to the posterior end of the suture 92 mm. (82) Projection on mesethmoid in prenarial region 18 mm. (25) In front of this the mesethmoid widens to a maximum of 30 mm. (30) Extends in front of nares 21 cm. (20) Maxillary foramina Right 50 mm. (30) Left 38 mm. (37) The exit of the right maxillary foramen is by two apertures, the inner one being quite small. In the Wanganui specimen the exit of the left maxillary foramen is by two apertures. the inner one being quite small. Evidently this is a variable character. Premaxillary foramina Right 13 mm. (15) Left 15 mm. (17) Width of premaxillae at foramina Right 48 mm. (50) Left 46 mm. (41) Greatest width—at front of nares Right 76 mm. (80) Left 64 mm. (70) Least width—at side of nares Right 44 mm. (36) Left 35 mm. (33) Total length of vomer 71 cm. (65.5) Apex acute and measures from tip of premaxillae 18.5 cm. (15) Height of back of skull 41.3 cm. (31) Foramen magnum 60 × 53 mm. (45 × 45) Right condyle 108 × 64 mm. (105 × 62) Width across condyles 169 mm. (153) Principal Measurements of Skull: Total length 122.5 cm. (114.8) Height—vertex to inferior border of pterygoids—abraded 39 cm. (41.6) Width across zygomatic processes 52.3 cm. (50.5) Tip of rostrum to posterior border of pterygoids—abraded 94.8 cm. (95.8) Rostrum—length from level of bases of antorbital notches 86.4 cm. (81) Rostrum—width between bases of antorbital notches 37 cm. (33.2) Rostrum—width at middle 14.6 cm. (11.5) Premaxillae, both, width across expanded proximal ends (one broken off) — cm. (17.4) Premaxillae, both, least width opposite anterior nares 16.2 cm. (15.7) Premaxillae, both, width opposite premaxillary foramina 11.7 cm. (11.8) Anterior nares, greatest width 8.7 cm. (9.5) Maxillary foramina, least distance between 11.9 cm. (13)

Acknowledgments. I wish to express thanks to Mr. A. W. Traill and Mr. Geo. Leask for the information they supplied. I also wish to acknowledge my indebtedness to Mrs. J. Harrison for the loan of the negative showing the whale cast up on Mason's Bay. Reference. Oliver, W. R. B., 1937. Tasmacetus shepherdi: A new Genus and Species of Beaked Whale from New Zealand, Proc. Zool. Soc., ser. B, part 3, 1937.