In 1922, Mr. W. D. Southcott of Hastings, New Zealand, discovered the remains of a fossil pinniped at Cape Kidnappers on the North Island of New Zealand. The fossil included a partial lower jaw, with all premolars and molars, both lower canines (isolated), and a fragment of one of the maxillae ("snout"). The fossil was collected about 20 feet above the beach on the lower bank of a tall cliff. This partial fossil was brought to the attention of the the paleontologist J. Allan Berry. Berry apparently spent quite an effort trying to pinpoint the exact locality and stratigraphic horizon, which he concluded to have been collected from sandstones of Opoitian age, just below the "Black Reef Limestone'. At the time, Berry considered the sandstones to be of early Pleistocene age. In 1928, he published the find in the Transactions of the New Zealand Institute, and named it Arctocephalus caninus. At the time, he considered it to be morphologically closest to the New Zealand Sea Lion, Phocarctos hookeri - which at the time was known to Berry as Arctocephalus hookeri. Although the genus name Phocarctos was named in 1866 - the taxonomy of otariids (fur seals and sea lions) has been volatile in the past, and although there is finally a consensus on what names to use now (see Berta and Churchill 2011), nearly every genus name in existence for fur seals and sea lions has been used for nearly every species, regardless of the names of modern usage. Berry compared the specimen with a number of New Zealand sea lion skulls and jaws, and concluded based on the presence and lack of various cusps on the cheek teeth and the shorter and apparently more robust canines, that it was distinct from Phocarctos hookeri. Additionally, the small size and gracile nature of the jaw suggested to Berry (1928) that the fossil represented a female - but the teeth were so much larger than modern females of Phocarctos, and it must have been a separate species.
The holotype of Arctocephalus caninus. From Berry and King (1970).
Comparison of a modern subadult male Phocarctos hookeri jaw (above) and Arctocephalus caninus (below). From Berry and King (1970).
The alleged type locality of Arctocephalus caninus, with the midden at the top of the cliff.
From Weston et al. (1973).
This skepticism led Weston et al. (1973) to re-reexamine Arctocephalus caninus, and one of the first tests that they did was to do the "flame test" - an old fashioned, tried and true field test to see if a bone is modern or fossil. The idea is that modern bones still retain enough of an organic component that they will smell like shit if you hold a lit match or lighter up to them - for anyone who's ever smelled burning hair - it smells like that. Really, really, really nasty; I've only smelled it once, and that was to provide a control for the flame test - I cut off a tiny bit of my hair and lit it on fire, and damn it smelled bad (and so did the bone in question). To make a long story short, the "Cape Kidnappers Fur Seal" failed the test, and reeked of burning bone smell. Apparently the source is fumes from burning collagen; at the time (we know better now, with collagen being preserved in Cretaceous dinosaur fossils) it was thought that this test indicated an age younger than 10,000 years. It probably does, to a degree- trace amounts of collagen in Cretaceous bones likely would not be sufficient enough to produce a stink, and the test probably indicates abundant collagen remaining in the bone rather than absolute presence or absence. Weston et al. (1973) extracted collagen from bone samples of the Arctocephalus caninus holotype and conducted a thin-layer chromatographic analysis, and compared it with results for a number of other finds of known pre-Holocene age and several other finds that had been radiocarbon dated. Their results indicated that it had an intermediate amount of surviving collagen between a modern bone and a bone from a midden dated at 878 years before present, thus indicating that the Arctocephalus caninus holotype is younger than 1,000 years old and a subfossil. Weston et al. (1973) further indicated that at the discovery site, there is a late Holocene midden with Maori artifacts, and bones and shells from the midden frequently wash down the cliff. The Maori are known to have colonized New Zealand only within the last 800 years or so. Weston et al. (1973) suggested that Arctocephalus caninus is a modern Phocarctos hookeri that washed down from midden deposits and came to rest in loose Pliocene age talus on the side of the exposure, making it appear as though it had genuinely weathered out of Pliocene rocks.
Ironically, when you think about it - at the time of discovery, most holotype specimens of fossils have never been seen before by any human - except in this case, where the evidence points toward an ancient Maori hunter who not only saw the sea lion many hundreds of years ago - but probably killed the animal, long before Mr. Southcott came along and made his own discovery. Also, ironically, I chose to start off this series with something that is most likely not even a fossil. I would have said this at the beginning, but I didn't want to spoil the story.
J. A. Berry. 1928. A new species of fossil Arctocephalus from Cape Kidnappers. Transactions of the New Zealand Institute 59:208-211.
J. A. Berry and J. E. King. 1970. The Identity of the Pliocene Seal from Cape Kidnappers, New Zealand, Previously Known as Arctocephalus caninus. Tuatara 18(1):15-18
Boessenecker, R.W. 2011. New records of the fur seal Callorhinus (Carnivora: Otariidae) from the Plio-Pleistocene Rio Dell Formation of Northern California and comments on otariid dental evolution. Journal of Vertebrate Paleontology 31(2):454-467.
Miller, E. H., H. Sung, V. D. Moulton, G. W. Miller, J. K. Finley, and G. B. Stenson. 2007. Variation and integration of the simple mandibular postcanine dentition in two species of phocid seal. Journal of Mammalogy 88:1325–1334.
Weston, R.J., Repenning, C.A., and Fleming, C.A. 1973. Modern age of supposed Pliocene seal, Arctocephalus caninus Berry (= Phocarctos hookeri Gray), from New Zealand. New Zealand Journal of Science, 16:591-598.