This is part 1 of the fossil record of early cetaceans of New Zealand, with an introduction to the stratigraphy and geology, and the archaeocetes and toothed mysticetes from NZ. For toothless baleen whales, see part 2 here, and for "dolphins" (Odontoceti), see part 3 here.
The holotype teeth and earbones of Kekenodon onamata - one of the earliest named fossil cetaceans from New Zealand, and by far the most consistently enigmatic. From Hector (1881).
New Zealand is a special place - a rainy, lush, cold island nation in the south Pacific. A veritable lost world - when the first Polynesians arrived around 1300 CE, the island was populated by gigantic birds. When Europeans (Pakeha) first "discovered" New Zealand, the Maori oral tradition was so strong that there were still names for these - the moa - despite having been driven to extinction centuries before. The bird fauna and plant flora are still very distinctive, despite disappearance of many of the larger species. New Zealand is just the exposed portion of the landmass Zealandia - technically a microcontinent. However, it's the largest of these, and also known as the "eighth continent" owing to its size: it's half the size of Australia, and more than six times the area of the second largest 'microcontinent', Madagascar. Most of Zealandia is underwater - about 94% - yet composed of light, silica rich continental crust that just happens to be mostly submerged, forming broad swathes of shallow continental shelf that is considerably shallower than the abyssal plain surrounding it. Other well-known islands that are parts of Zealandia include the Chatham Islands east of Dunedin, Stewart Island south of Invercargill, New Caledonia, Norfolk Island, and nearly 700 additional islands in the region.
New Zealand, that part of the world frequently left off of world maps! While few are familiar with New Zealand other than "it's near Australia, I think", the lost continent of Zealandia - here outlined in pink - is even less well known to the public. All of that shallow continental shelf is continental crust, a large chunk of Pangea that rifted apart - it's about 2/3 the land area of Australia, and also includes New Caledonia. Image credit: NOAA via Wikimedia.
New Zealand has also been largely submerged for much of its history - resulting in a fantastic marine fossil record that is nearly continuous from the late Cretaceous to the Pleistocene. Part of this marine record - the Oligocene epoch - led me to move to Dunedin with my wife Sarah in 2012 and begin my Ph.D. research on fossil whales with Dr. Ewan Fordyce in the Geology Department at the University of Otago. Much of the information I'll be covering in these posts is either based on fossils discovered by Ewan or published or otherwise studied by him and his students. Sadly, Ewan passed away in November 2023. I've decided to restrict this post to the Eocene and Oligocene record of archaeocete, mysticete, and odontocete fossils from the country, and may delve *a little* into the early Miocene - the fossil record of cetaceans from the mid-late Miocene and Pliocene is much more spotty, and the real "meat" is in the "middle" Cenozoic - approximately 40-20 million years ago. Furthermore, virtually all of these fossils are from the South Island, and specifically the southern Canterbury Basin in the vicinity of Oamaru - chiefly the Waitaki Valley and the Hakataramea Valley.
Some notes on Maori (and Polynesian) pronunciation
New Zealand is notable for being the southwestern tip of the Polynesian triangle - defined as all the islands and waters between New Zealand, Hawaii, and Rapa Nui (aka Easter Island). Maori (pronounced Maw-ri - not Mow-ri, e.g. not rhyming with 'Now') is not too dissimilar from Hawaiian or Tongan, or Tahitian* for that matter. Many of the words are very similar - for example, in Maori a 'k' would be present where in Hawaiian there would be a 't' - famous Waikiki beach would become Waititi, which happens to be the last name of the critically acclaimed director Taiika Waititi (who was still very much a local phenomenon when we were there, mostly showing up in a bunch of hilarious beer commercials).
*The 'a' in many Polynesian words is typically pronounced longer than we think if we were reading English words. Tahiti and Samoa are not "tuh-heetee" or "suh-mo-uh" but "taw-hee-tee" and "saw-moe-uh". On a family trip to Oahu in 2001 I recall learning this at the Polynesian cultural center, and the memory of it jolted back into my brain after a few days in Dunedin. To alleviate this, when you're actually in New Zealand, the 'long A' is usually identified with a macron.
What's really impressive is that Polynesia was settled so rapidly and efficiently that the language has barely had any time to change - the Polynesian settling of the south Pacific started around 700 AD with their arrival in the Marquesas, Cook islands, and Tahiti; by 800-900 arriving in Samoa, Hawaii, and Tonga, and around 1000-1200 Rapa Nui (Easter Island), and lastly, exploring south and settling Aotearoa (New Zealand) by 1200 (Moa became extinct by around 1450). Contact with westerners like the Dutch explorer Abel Tasman did not occur until the 17th century (though the Spanish and Portugese made contact with the peoples of Melanesia and Micronesia further to the north, e.g. Guam, during the prior century). Captain James Cook landed in Tahiti and Tupaia, a Tahitian 'priest' of sorts, befriended the chief botanist of the expedition, Joseph Banks (who would later become the most influential president of the Royal Society), and joined the expedition. His story is remarkable - trained as a star navigator, from memory, he was able to correctly map out at least 134 islands within 2000 miles and provide the names of at least 70 of them. However, the most remarkable - and relevant - part of the story here is that once arriving in New Zealand a few months later in October 1769 - over 4,000 kilometers away - Tupaia was able to speak with the Maori and have mutually intelligible conversations. Like anywhere else in Polynesia, there were of course some dialect differences, but the recent and rapid colonization of Polynesia meant that the language is surprisingly similar over vast differences - no doubt stabilized by continuous maritime trade and voyages between islands (on Tupaia's map, for example, he indicated that he had personally visited at least 13 of the islands, and that his ancestors had visited all of them, except for an island north of Fiji, and Oahu. Anyway, there's a fabulous book titled Voyagers by Nicholas Thomas that goes into the rich history of the Polynesian colonization of the Pacific.
Now, onto some pronunciation (and take this with a grain of salt as even Pakeha living in NZ for three years cannot do a great job pronouncing everything properly):
The 'r' in Maori words is typically rolled, slightly - but not so extravagantly as in Spanish.
'i' is always an 'eee' sound.
'wh' in the South Island dialect is, strangely, pronounced as an 'f' - this is likely due to a bad translation error made by Pakeha (foreigners) in the late 19th century. Because all of the fossil cetaceans from NZ are based on fossils from the South Island, the 'wh' is always pronounced as an 'f'. So - the species name for the dolphin Waipatia maerewhenua? That's 'mare-reh-fen-you-uh'. In various North Island dialects, wh sounds identical to w.
T is always hard. Waipatia might be spelled like the name of the Hellenic scholar Hypatia, but the -tia is not pronounced 'sh'.
There are a ton of dipthongs in Maori:
'ai' is pronounced like I, e.g. 'Wai' is "why".
'ae' is pronounced like 'ai' in English, e.g. the way you would pronounce 'air', 'fair', or 'hair'.
'ua' is pronounced 'you-uh'
'ui' is pronounced 'you-eee'
'oi' is 'oy', so if you
'au' is a difficult one, but sounds like 'oh'.
'ou' is pronounced more like 'ooo'.
'eo' is pronounced 'eyyy-oh'
I'm sure I've missed some, but if you're wanting to learn more, check out resources like this: https://www.maorilanguage.net/how-to-pronounce-maori/.
Now, one major wrinkle to learning Maori pronunciation is that you have to do it while learning New Zealand pronunciation of English, which is barely English. It was one thing speaking with Fordyce at conferences in the USA and Canada, despite his very distinctive accent - he knew to use American words rather than their 'kiwi' counterparts. This kindness left me more or less completely unprepared while ordering food, drinks, taxis, etc. while speaking with New Zealanders. Ironically, exposure to Tongan accents in high school and visits to Hawaii meant that I didn't find Maori accents too difficult, but good lord, it was tough understand white New Zealanders. Aside from a completely different vocabulary for every day items and activities, the vowels are all shifted: a becomes e, e becomes i, i becomes a u of all things. Fish becomes 'fush', fashion is 'feshion', flesh becomes 'flish'. Despite being close to Australia (Ewan would deliberately draw out the aaaust, like someone here making fun of a Texan accent), New Zealand pronunciation is anything but: where vowels are drawn out into the down-under version of a southern drawl ('no' has like three different vowels in it and ends in an r, like 'naaur'), in NZ the vowels are short and clipped, meaning that innocent Americans are frequently going to look confused until a waiter will give a loud, and painfully drawn out American-ized pronunciation (this happened constantly for about the first month I was down there!). If you want some more exposure to the lovely and bizarre Kiwi accent, I encourage you to watch such films as What we Do in the Shadows, The Hunt for the Wilderpeople, or the show Flight of the Conchords.
A regional geologic map of Zealandia and surrounding trenches. For non-geologists, the lines with the black teeth on them are thrust faults/subduction zones, the teeth pointing towards the overriding slab. Note how the teeth change direction from along the Kermadec trench northeast of New Zealand (oceanic crust moving west and being subducted) versus the Puysegur trench (oceanic crust on west being subducted under east). This difference in direction is largely responsible for formation of the Alpine fault, which is *mostly* a strike-slip fault, and has resulted in shearing of New Zealand. From Schellart et al. (2006).
Major Geological Events in New Zealand
Today, Zealandia is located at the southern terminus of the Tonga-Kermadec Trenches* - a subduction zone formed where the Pacific Plate is being subducted below the eastern edge of the Australian Plate. This subduction zone transitions into a transform boundary - forming one of the largest strike-slip faults in the western Pacific: the Alpine Fault. This is sort of the southwestern Pacific equivalent of the San Andreas fault. For every four meters of lateral movement, there is an additional meter of uplift - resulting in the incredibly rugged Southern Alps on the South Island. I've been there, they are nothing short of magnificent - and if you've seen The Lord of the Rings, you'll certainly agree. Strike slip faults are of course not static - they move continental crust around horizontally - so New Zealand (the emergent, major landmass of Zealandia) has undergone quite a bit of change as it has been sheared over the course of the Cenozoic. Just as the rocks to the west of the Alpine Fault are part of the Australian Plate, the rocks to the east are part of the Pacific Plate. South of the South Island, the plate boundary goes back into the ocean, forming the Puysegur trench between the Australian and Pacific plates, which continues south (with some name changes) towards the Macquarie Triple Junction where a spreading ridge is producing more oceanic crust, resulting in the slow push of the Pacific Plate north and west, causing all of the subduction and also the slow movement of the parts of New Zealand east of the Alpine Fault north, scraping against the rest of the landmass to the west.
*There is a volcanic arc that runs northeast along the Kermadec and Tonga trenches, and this trench makes a left (westward) turn at Tonga/Fiji. Tonga marks the eastern-most volcanic arc in the south/tropical Pacific, defining a major geological boundary called the "Andesite Line". Andesite at minimum requires some continental-ish rock enriched with at least a little bit of silica to form - and andesitic volcanoes are on the bigger end of things, forming towering stratovolcanoes, also known as composite volcanoes, like Mt. St. Helens, Mt. Rainier, Crater Lake (formerly Mt. Mazama), Mt. Fuji, and Mt. Taranaki in NZ (Mt. Taranaki stood in for Mt. Fuji in "The Last Samurai" and Mt. Doom in Lord of the Rings). Stratovolcanoes tend to explode, and some of the most famous eruptions on earth - Krakatoa and Tambora - erupted west of the Andesite Line, in Indonesia. All volcanism east of the Andesite Line consists of intraplate volcanism only - volcanoes shooting up magma at hotspots, burning holes in oceanic crust, forming un-enriched heavy, iron/magnesium rich and super runny basaltic lava. East of the Andesite Line you get Hawaiian-style eruptions - eruptions you can walk, run, or drive away from. West of the Andesite Line? Explosive eruptions that might kill you by pyroclastic flow, steam explosions, tsunamis, or regional devastation that might alter the long term livability and economy of your island.
There are plenty of older rocks in the country, but the story of Zealandia really starts in the Cretaceous when it finally split apart from Australia - and no self-respecting Kiwi would want to dwell on a time period where Zealandia was simply part of Australia! Around 80 million years ago, continental rifting resulted in Zealandia breaking off the east coast of Australia and migrating eastward. A brief refresh: the famous supercontinent Pangea formed during the Carboniferous period some 300 million years ago, and began to rift apart around 200 million years ago around the Triassic-Jurassic boundary. By the late Jurassic, Pangea had rifted into two major landmasses separated by a narrow North Atlantic: Laurasia (North America, aka "Laurentia", and Europe/Asia), and Gondwana (South America, Africa, Madagascar, Antarctica, Australia, India, and Zealandia). By the early Cretaceous, the South Atlantic began to form, separating South America from Africa; Africa started drifting North, with Madagascar also separating from everyone else, and India began skittering northwards at a breakneck pace (and it would eventually collide with Asia around ~40 million years ago in the late Eocene, beginning the uplift of the Himalaya, which are of course still being uplifted today).
What this resulted in was a big of a strange remnant of Gondwana: South America, Antarctica, Australia, and Zealandia (for a short while) remained connected in the "west" to the Antarctic Peninsula (which is in West Antarctica) and Australia to the north of East Antarctica, and Zealandia stuck on to the east coast of Australia. Zealandia separated first, and drifted at a leisurely pace (much, much, much slower than India), while Australia, and South America remained attached to Antarctica until the Eocene epoch. During the mid-late Eocene, each of these landmasses finally began to rift apart from Antarctica. It's uncertain which happened first, but what's very neat is that thanks to fossils from Seymour Island (same locality as Llanocetus, the oldest baleen whale), there were South American mammals inhabiting the Antarctic Peninsula well into the middle Eocene. Some of these fossils indicate that there were early Xenarthrans present - the group including modern armadillos, sloths, and anteaters - along with litopterns, an extinct group of placentals also unique to South America - and a host of different marsupials with South American links. Plant fossils indicate a temperate forest dominated by southern beech (Nothofagus), very similar to the native forest in New Zealand today. Given these fossils, it's likely that South America was still firmly attached - but the opening of the Drake Passage between Antarctica and South America is still unclear. The date of separation between Australia and Antarctica - the formation of the Tasmanian Seaway - is better understood, and seems to have opened to such a degree to permit deepwater circulation by 33.5 mya. This changed everything - locally, but also on a global scale - with permanent consequences for the earth since.
The final separation of these landmasses finally isolated Antarctica, resulting in the setup of the deep water Circum-Antarctic Current, sometimes called the circumpolar current, or the Antarctic Circumpolar Current (ACC). The ACC is the world's refrigerator: this west to east current prevents a southern hemisphere version of the gulf stream from delivering any warm, moist air - and seawater - to Antarctica. Antarctica, formerly a temperate forest teeming with life similar to its former neighbor continents, became rapidly glaciated at the Eocene-Oligocene boundary. With no possibility of interference of warm air and water, each winter became slightly cooler until it was cold enough to snow year-round, eventually forming the first continental ice sheets on the continent.* The famous La Meseta Formation on Seymour Island, where marine faunal change at the south pole during the Eocene has been best studied - terminated sedimentation, as sea level was lowered considerably below. In many places in the world, the Eocene marine record simply ends and rocks of late Eocene age are overlain by terrestrial rocks, or incised into by erosional surfaces (as nonmarine sedimentation on coastal plains is scattered and unreliable, often haphazardly causing widespread erosion and limited nonmarine deposition). At the famous Egyptian locality Wadi-Al-Hitan ("Valley of the Whales"), for example, the spectacularly fossiliferous marine sequence from which ~10 million years of incredible fossils chronicling whale evolution, ends with the deposition of the shallow marine to lagoonal Qasr el Sagha Formation of latest Eocene age, and is overlain by the nonmarine Oligocene Gebel Qatrani Formation - which produced some pretty famous land mammals like the early proboscideans Moeritherium and Phiomia and the double-horned embrithopod Arsinoitherium. While I would prefer some Oligocene cetaceans of course, maybe it's OK to have gotten some early afrothere 'weirdos' like these, I'd call that a solid tradeoff between marine/nonmarine fossils!
*This is the traditional model of Antarctic glaciation - however, there's some evidence of a smaller ice cap earlier, perhaps during the middle Eocene and even the late Paleocene has been suggested - and the glaciation has also been hypothesized to stem from a decrease in atmospheric CO2 - formerly in the thousands, it dipped below the 600 ppm tipping point, triggering a rapid transition from greenhouse to icehouse conditions. Within the last decade, we recently exceeded 400 ppm CO2, transitioning from a pre-industrial ~280 ppm.
In Europe the Eocene-Oligocene boundary marks an extinction event where many endemic mammals became extinct, and were replaced by invading mammalian species of Asian origin - this faunal difference has been called "Grande Coupure", or "the big break". Cooling during the Oligocene led to limited expansion of grasslands and more temperate forests, and a bit of a reduction in tropical rainforest/jungle habitat that was so common during the Eocene.
Geographic and tectonic evolution of New Zealand, with modern shorelines superimposed. It used to look quite a bit different, and is only elongated into the two islands now because of shearing along the Alpine fault. From Reilly et al. (2015).
In New Zealand, there isn't as much of a stark difference because most of Zealandia remained underwater. middle-late Eocene rocks are plentiful, though sparsely fossiliferous and with sparse outcrops. Terrestrial pollen from NZ shows a transition from warm, humid forests to more temperate forests during this time, but as far as marine rocks are concerned, little much of a difference. In fact, around the Eocene-Oligocene boundary, the sequence is interrupted along the Otago coast by volcanic rocks. The Ototara Limestone - a thick, monotonous tan to white limestone mostly composed of bryozoan fragments* - preserves the Eocene-Oligocene Boundary, marked by the extinction of the foraminifer ("plankton") Hantkenina.
*Also known commercially as Oamaru-stone or Totora-stone, virtually all pre-WW1 buildings in the town of Oamaru are carved from this limestone, making it quite bright/reflective on a rare sunny day, and also a popular source of stone for local sculptors. I still regret not purchasing a Muri Paraoa (whale flukes) I saw for sale at a farmer's market in Dunedin, but it would have come at the cost of a week's groceries and any heat we would have needed.
The first noticeable perturbation in the marine record of NZ is a widespread erosional surface, called by earlier stratigraphers as the "Marshall Paraconformity". An unconformity is an erosional surface, and a paraconformity is one such type - it's basically similar to a disconformity, where there is a difficult-to-identify erosional surface present between rock layers above and below that are parallel in bedding, differing from an angular unconformity where the rocks below have been tilted. The "Marshall Paraconformity" itself has been a locally controversial topic amongst NZ stratigraphers (summarized here by Mike Pole) and in reality might be two or more different unconformities, which seem to have erased 2-3 million years of the marine record in parts of NZ. In the whale-bearing rocks of the south Canterbury Basin, the top of the Ototara Limestone is heavily bored/bio-eroded and even shows evidence of karst dissolution. It has been overlain by the Kokoamu Greensand. Further inland, the Ototara Limestone transitions into the deeper marine Earthquakes Marl, and further inland yet, the Wharekuri Greensand - also overlain by the Kokoamu Greensand. The cause of this erosion is unclear, but may have been driven by some "glacioeustatic" fluctuations in sea level - brief expansions of the Antarctic Ice sheet that temporarily lowered sea level during the middle Oligocene.
Maps of likely emergent land from the Oligocene onward, modified from work by Charles Fleming. From https://slideplayer.com/slide/16841854/.
The last relevant geological event may or may not have happened - but during the Oligocene there was a period of rather high sea level - that may, or may not, have completely submerged Zealandia. This debate was raging just as I got to New Zealand. During the Oligocene, there are basically no terrestrial sediments, and all known Oligocene aged marine rocks are marine. Many geologists argued that this indicated the entire landmass was completely underwater for at least a few million years - highlighting many lineages of terrestrial organisms that seem to have been post-Oligocene arrivals, and the complete absence of native terrestrial mammals, aside from bats, which almost certainly flew across the Tasman sea. However, plenty of scientists - Fordyce included - fervently disagreed, pointing out that there's no shortage of lineages that either 1) are endemic today and have molecular divergence dates from other endemic species pre-dating the Oligocene and 2) some animals like the Tuatara, Sphenodon punctatus - a strange lizard-like reptile that is today unique to New Zealand. This group, the Rynchocephalia, were formerly globally distributed during the Mesozoic (and were quite diverse here in North America during the Triassic), but declined during the early Cretaceous, restricted to what remained of Gondwana (South America, Antarctica, Australia, Zealandia) after becoming extinct in North America, Europe, Asia, and Africa during the early and late Cretaceous. Though no pre-submergance Tuatara are known from NZ, their last occurrence outside Zealandia is from the earliest Paleocene of Patagonia, strongly suggesting that they've been endemic to Zealandia since the Paleocene.
Ewan Fordyce teamed up with Ken Rose, Hans Dieter-Sues, Carolina Loch, and Mike Gottfried for a project called "The Lost Mammals of Zealandia", a search for Paleogene fossil land mammals in shallow marine sediments where he had found some evidence that terrestrial fossils might be found. As of 2014, no precious mammal teeth had been discovered during the pilot project, but a single crocodylian tooth had been recovered - the oldest from the continent. The hope was, if any land mammal teeth were found, they would be readily identifiable and with likely biogeographic signal (e.g., these teeth clearly resemble species from Australia, which, all nationalistic joking aside, is the most predictable affinity for any Paleogene Zealandian mammals). The search continues.
The New Zealand Geological Time Scale and mid-Cenozoic Stages
In a characteristic display of independence, New Zealand proudly boasts its own Geologic Time Scale. I had some knowledge of this prior to my arrival in 2012, but had a bit of a baptism by fire my first few months. New Zealand is so isolated, that many of the correlations of marine rocks in Zealandia require careful comparisons between other NZ localities, rather than Australia or further afield - necessitating to a degree its own time scale. Australia has its own time scale, for similar reasons, though it is less widely used than the international scale.* These are chronostratigraphic units, relating physical rock layers to specific periods of time. Most chronostratigraphic units are based on a reference section somewhere on earth. In the case of the Duntroonian Stage - one that we're going to talk about the most in this series, I think - is based on exposures of the Oligocene Otekaike Limestone in the vicinity of Duntroon, New Zealand. More on Duntroon later.
*Along the west coast of North America, we have several timescales for each type of microfossil - the diatom zones, initially divided into stages with roman numerals, and benthic foraminiferal stages like the Eocene-Oligocene Narizian, Refugian, and Zemorrian stages - sadly, best a cudgel-like biostratigraphic tool rather than a scalpel. In the past two decades Pacific coast stratigraphers have more completely adopted the international stages defined by the ICS, largely defined on European localities.
For the period of time concerning fossil whales, we're really focused on the Bortonian, Kaiatan, Runangan, Whaingaroan, Duntroonian, and Waitakian stages. The Bortonian through Runangan are Eocene in age, with the Bortonian confusingly being broadly equivalent to the Bartonian middle Eocene stage; the Kaiatan and Runangan are generally late Eocene in age, roughly equivalent with the international Priabonian stage. These three stages comprise the Arnold Series - named after strata exposed along the Arnold River in the West Coast district of the South Island. Likewise, the Runangan is
The next three are roughly coincident with the Oligocene, but actually include the last million years of the Eocene and the first two million years of the Miocene. The Whaingaroan stage is broadly equivalent to the Rupelian of international usage (early Oligocene), while the Duntroonian represents the early Chattian (late Oligocene), and the Waitakian stage represents the latest Oligocene and first million years or so of the Miocene. These three stages make up the Landon Series, named after Landon Creek, between Oamaru and the mouth of the Waitaki River. The Whaingaroan is named after strata in the vicinity of Whaingaroa, south of Auckland on the North Island, whereas the Duntroonian derives its name from the hamlet of Duntroon along the Waitaki River in South Canterbury - which also happens to give its name to the following Waitakian stage.
Generalized stratigraphy of the southern Canterbury Basin (occasionally called the Waitaki Basin by some authors, but not Otago geologists). From Thompson et al. (2014).
A Brief Introduction to mid-Cenozoic Stratigraphy of the Canterbury Basin
Deposition of the Canterbury Basin starts in the Cretaceous, and the late Cretaceous Katiki Formation has produced spectacular fossils like Kaiwhekea - the "shag point" plesiosaur*, and a sparsely fossiliferous sequence from the Paleocene and early Eocene.
*'Shag' is an archaic English name for cormorants. Fordyce always called this specimen "Shagosaurus" to get some laughs.
Waihao Greensand: The Waihao Greensand is middle to late Eocene in age, and best exposed in the vicinity of Waihao in south Canterbury. This unit is a massively bedded glauconitic sandstone, frequently a grayish green color. Invertebrates are rare but include a fossil lobster. Many bony fishes are reported form otoliths. The leatherback sea turtle Psephophorus terrypratchetti was reported, along with specimens of Zygorhiza (see below), are the best known vertebrates from the Waihao Greensand.
Ototara Limestone: One of the more important sedimentary units, historically used as a source of building stone; most of the older buildings in the coastal town of Oamaru are built out of this material, colloquially called "Oamaru Stone" (some of the parts of the Geology and Registry buildings at Otago are made of this material as well). It's also used for stone carvings, quite common on the South Island. The Ototara Limestone is dominated by bryozoan fragments, giving it a medium to coarse sandy texture. It's frequently massively bedded, and in the vicinity of Kakanui, interfingers with lavas from small marine cinder cones. The Ototara Limestone is Eocene through early Oligocene in age. The very first fossil penguins ever reported were discovered in the Ototara Limestone in the 1840s - indeed, Palaeudyptes antarcticus was named in 1847 by none other than Darwin's bulldog, Thomas Huxley. Later, the titanic penguin Pachydyptes was also named from the Ototara. The only cetacean to be reported from this unit is the "Protosqualodont" of Keyes (1973).
Amuri Limestone: This unit is a lateral equivalent of the Ototara Limestone, and exposed in North Canterbury. It is a chalky unit consisting mostly of coccoliths and foraminifera deposited in outer shelf to slope settings. So far only one fossil cetacean is known from this unit, ZMT 62.
Earthquakes Marl: This unit is poorly exposed and has not produced much in the way of significant vertebrates, but is a lateral equivalent of the Ototara Limestone, typically exposed further inland. It is the lowermost unit exposed at "The Earthquakes" and Waipati. It consists of gray calcareous siltstones
Kokoamu Greensand: This unit is a sandy, invertebrate rich outer shelf deposit consisting of pervasively burrowed, massively bedded glauconitic sandstone. It is considerably more friable and tends to weather away rapidly at the base of cliffs, and natural exposures typically include only the uppermost couple of meters below the Otekaike Limestone. The Kokoamu is uppermost Whaingaroan in age to upper Duntroonian (~28-26 Ma). Common fossil invertebrates include brachiopods and scallops, especially at the top of the unit, where it becomes more calcareous - leading to a gradational contact with the overlying Otekaike Limestone. Fossil sharks, penguins, and cetaceans are common; fossil cetaceans include Mammalodon hakataramea, Kekenodon onamata, Tohoraonepu nihokaiwaiu, Tokarahia lophocephalus, Tohoraata waitakiensis, Matapanui waihao, and Toipahautea waitaki. Two species of dolphins have been named from the Kokoamu, both waipatiids - Awamokoa tokarahi as well as Nihohae matakoi, though there is an unnamed squalodontid as well; doubtless there are others. Penguins include the giants Kairuku waitaki and Kairuku grebneffi, and the earlier named Archaeospheniscus lowei, and Platydyptes marplesi. The Wharekuri Greensand and "Kekenodon beds" are lateral equivalents of the Kokoamu Greensand.
Otekaike Limestone: This unit overlies the Kokoamu Greensand and the two units constitute a depositional package. The Oteikaike Limestone is glauconitic at the base and grades up into a sandy, foraminiferal limestone, representing middle shelf deposition and preserves abundant invertebrates - most common are bivalves, bryozoans, brachiopods, gastropods, and tube worms, but crinoids, basket stars, and cold water corals (including octocorals) are also present. The Otekaike Limestone is massively bedded and a ridge former, and many spectacular cliffs are developed in North Otago and South Canterbury; some of these cliffs even appeared in the first Hobbit movie (though possibly could have been the Weka Pass Limestone). It dates to the late Oligocene, being about 26-22 million years old, or Duntroonian through Waitakian. Locally it is an important source of agricultural lime, and Hakataramea Quarry is a critical source of such lime. The Weka Pass Limestone in North Canterbury is a northern equivalent of this unit (the cliffs in the final battle in The Lion, the Witch, and the Wardrobe were filmed at a famous Weka Pass Limestone exposure) - though it is nowhere near as rich in fossil vertebrates. This unit is easily the most heavily studied in New Zealand. Many fossil fish and sharks, including the giant shark Carcharocles angustidens, the giant moonfish Megalampris keyesi, and the billfish Aglyptorhynchus hakataramea are all known from the Otekaike Limestone (though far down in the lower, glauconitic limestone in the case of the former two). Penguins include Platydyptes and the recently named dwarf penguin Pakudyptes. Fossil cetaceans are common and include a kekenodontid archaeocete (new genus and species), waipatiid dolphins (Waipatia maerewhenua, Waipatia hectori, Nihoroa reimaea, Aureia rerehua, Otekaikea marplesi, Otekaikea huata), at least one squalodontid (the Earthquakes squalodontid), eomysticetids (Tokarahia kauaeroa, Tohoraata raekohao, Waharoa ruwhenua), "Tsai's whales" (Whakakai waipata, Toipahautea waitaki, Horopeta umarere), Mauicetus and friends (Mauicetus parki, and ZMT 67). There are other "interesting" (to put it extremely mildly) cetaceans I can't talk about, but at least one has been reported in a conference abstract: a mysticete with an arched rostrum, OU 22224, which Ewan originally considered to be an Oligocene balaenoid (right whale), but at present, might instead be something more archaic (see part 2).
Gee Greensand: The Gee Greensand is a thin, friable glauconitic sandstone of early Miocene (Otaian stage, ~19-21 Ma) age and is mostly exposed close to the coast, such as in the vicinity of Kakanui (and poorly exposed at that). The Gee Greensand has produced a single fossil cetacean, Tangaroasaurus kakanuiensis.
Mt. Harris Formation: The Mt. Harris Formation conformably overlies the Otekaike Limestone and consists of somewhat deeper marine siltstone; in the vicinity of Awamoa Beach, numerous light gray siltstone concretions have been collected that contain cetacean bones. Few fossil cetaceans have been reported from this unit, other than a partial skull of Prosqualodon. Many others are sure to follow. The Mt. Harris Formation is Otaian to Altonian, roughly 21-18 Ma in age.
Caversham Sandstone: The Caversham Sandstone is a lateral equivalent of the Mt. Harris Formation, and is a thick, massively bedded yellow sandstone that forms the spectacular coastal cliffs southwest of Dunedin as well as further north of the Otago Peninsula from Karitane nearly to Shag Point. Only one fossil odontocete has been formally named from this unit, "Prosqualodon" hamiltoni, a large Phoberodon-like beast (see part 3); several smaller dolphins, including kentriodontids, were studied by Gabriel Aguirre-Fernandez as part of his Ph.D. thesis and await formal publication. The Caversham Sandstone is Otaian to Altonian in age (21-17.5 Ma).
The southeast cliff at Hakataramea Quarry, aka Haugh's Quarry - this was the original natural exposure, quarrying is to the left. The holotypes of Toipahautea and Horopeta were collected between where I was standing and where Ewan (red shirt) is, and the large hole he's examining is where the unnamed "Chocolate whale" was excavated. The grass-filled hole in the quarry at the upper left is where the paratype skull of Waharoa was collected. The olive green layer at the base of the cliff is the top of the 'mid' Oligocene Kokoamu Greensand, and the rest is all upper Oligocene Otekaike Limestone. Photo by me, 2013.
Tunnel Beach, South Otago, New Zealand - these impressive cliffs are exposures of the somewhat younger Caversham Sandstone (early Micoene). No mysticetes (or archaeocetes) from this unit, but I'll cover some of the odontocetes from this unit in part three. Photo by me, 2013.
The Fossil Record of Archaeocete Whales in New Zealand: Basilosauridae
Archaeocete whales - the ancestors of baleen whales and toothed whales - are predominantly known from the Eocene epoch, and document how hoofed mammals began experimenting with a semiaquatic existence, rapidly changing from an herbivory to carnivory, and the slow transition from a running mammal to one that swam, first quadrupedally, and then eventually with flukes and flippers. The earliest groups of archaeocetes, the semiaquatic raoellids, pakicetids, ambulocetids, are known only from India and Pakistan. The remingtonocetids were the first to be found preserved in marine strata, and have been found slightly further afield in Egypt (Rayanistes) and possibly eastern North America. The protocetids, the last group to have any ability to support their weight on land - have now been found in Indo-Pakistan, Egypt, Morocco, Europe, Togo, the southeastern USA, and most recently, Peru. The last group, the Basilosauridae, have a near-worldwide distribution - most famously they are known from Egypt and the southeastern USA, but there have been a number of amazing discoveries in Peru, such as well-preserved Cynthiacetus peruvianus and the titanic whale Perucetus colossus, and many additional as-yet undescribed species and specimens from the "valley of the archaeocetes".
This latter group is the only classical group of Eocene archaeocetes known from New Zealand. The first known specimen was a collection of three associated teeth from the Waihao Greensand of South Canterbury, described by Ewan Fordyce (1985). This specimen has a bit of an interesting post-collection history. One of these teeth, a single premolar similar to Saghacetus osiris, was present in the collections of the NMNZ collections at what is now Te Papa Tongarawea - the NZ national museum in Wellington (I'll just call it Te Papa if it comes up again), and mixed in with the type specimen of the problematic early whale Kekenodon onamata (keep reading), but morphologically and having some preservational differences. Fordyce noticed this in 1975 and concluded it was from a different specimen, but it bore no markings or associated notes to indicate exactly where it was from. Two years later, while visiting the Canterbury Museum in Christchurch (the other big city on the South Island other than Dunedin, and where Ewan did his Ph.D. research), he found a specimen consisting of a canine-like tooth and a fragment of a root, bearing the identification of "Crocodile Waihao". These other two specimens were preservationally similar to the mystery tooth found at Te Papa, but also share similar enamel thickness and surface tecture, along with similar rock attached - which happened to be similar looking greensand. What really clinched the identification was the fact that the three tooth fragments have identical glue attached to them, and were at one point affixed to a sheet of card and evidently put on display, and sunlight damaged the card but left little shadows showing the outlines of the teeth - and there was an outline matching the premolar found at Te Papa. The specimen was united and assigned a new specimen number at Canterbury Museum after this detective work. It is thought to have been collected very, very early - perhaps by the early geologist-explorer Julius von Haast, and Fordyce speculated that the premolar may have been taken to Te Papa in the 1880s during James Hector's study of what he later named Kekenodon onamata - the specimen was not figured or considered part of the type specimen by Hector. Fordyce concluded that these teeth are assignable to some sort of "dorudontine"* basilosaurid, and made comparisons with Saghacetus osiris from the uppermost Eocene of Egypt, and indicated that the tooth is a bit smaller than Zygorhiza from the USA. Critically, Fordyce also summarized other fragmentary records that had been assigned from the Oligocene of Australia and New Zealand and concluded that most of these other specimens represent archaic toothed mysticetes and odontocetes - the New Zealand specimens of which I'll review in this same series. As a result of this revision, Fordyce (1985) pointed out that this was the first definitive record of an archaeocete as well as the oldest known cetacean from NZ.
*The taxonomy of the Basilosauridae has been revised several times - most notably by Kellogg (1936), but later by Barnes and Mitchell (1978), who left lasting definitions of the "Dorudontinae" and "Basilosaurinae" - two subfamily names, placed here tactically in scare quotes - which have in recent years become less-than-useful ideas. Essentially, the Basilosaurinae was used to contain Basilosaurus cetoides and Prozeuglodon isis, gigantic species with elongated thoracic and lumbar vertebrae. However, P. isis was later reassigned to Basilosaurus and recombined as Basilosaurus isis, essentially making gigantic size and elongated vertebrae unique to the genus Basilosaurus - and making the subfamily not needed, because the "Dorudontinae" ended up including all other basilosaurids. With Perucetus, Cynthiacetus, Tutcetus, and the Basilotritus-Platyosphys-Pachycetus-Aithacetus quagmire, the situation has changed somewhat, and pending phylogenetic analysis of the family, perhaps some subfamilies may still be useful, but not until then.
Further Eocene archaeocete material would not be discovered until 1991, when collector P.A. Maxwell found a partial basilosaurid skull, and further field trips from 1992-1995 recovered a few additional specimens including teeth and some vertebrae. Owing to the rarity of specimens in the Waihao Greensand, and their close association, these specimens - though assigned different numbers - were considered to be one specimen. These specimens formed part of the basis for Richard Kohler's PhD thesis at Otago, and were formally published by Kohler and Fordyce (1997). These specimens were assigned to Zygorhiza, previously known only from the uppermost Eocene Yazoo Clay and equivalent units on the gulf coast of the USA - chiefly Louisiana, Mississippi, and Alabama. Zygorhiza has been differentiated from other basilosaurids only based on one major dental feature: having a well-developed ridge or cingulum at the base of the cheek teeth, absent in other basilosaurids. An additional dental feature seems to define Zygorhiza: a thick posterior root on the premolars, a vestige of the two posterior roots in earlier archaeocetes and land mammals that fused together. One other key feature is possessing a slightly "telescoped" skull - with the occipital shield, the bone that makes up the back of the braincase - shifted further like as is seen in early mysticetes and odontocetes, and a nuchal crest that forms a slight shelf. In other basilosaurids, it is instead vertical. Uhen (2013) found the top of the skull to be quite variable in Zygorhiza. Regardless, the Waihao basilosaurid possesses all three of these features, and was identified as Zygorhiza sp. by Kohler and Fordyce (1997).
More recently, a neonatal or perinatal archaeocete skeleton was discovered in the upper Eocene Ashley Mudstone of Canterbury and reported by Fordyce and Hiller (2014) in an SVP conference abstract. I saw the specimen in person during my Ph.D. - it is tiny - but has adult-sized periotics, and a skull measuring only about 30 cm, with a number of milk teeth. The specimen has not yet been published.
The Fossil Record of Archaeocete Whales in New Zealand: Kekenodontidae
In November 1880, a fragmentary archaeocete-like whale was discovered by Alexander McKay in the vicinity of Wharekuri Creek in the Waitaki Valley, from an Oligocene aged unit later called the Kekenodon beds, and later correlated with the Kokoamu Greensand. The specimen consists of a set of rather large teeth including incisors, a canine, premolars, and molars, along with the right frontal bone, a periotic, and a bulla. It seems likely to me, and when I suggested this, Ewan seemed to agree - that the original specimen as found in the field likely had rather crumbly, fragmentary bone that did not survive primitive collecting methods. As a result, only relatively durable parts remain. This specimen was named Kekenodon onamata by James Hector in 1881, who thought it may be similar to archaeocetes like Basilosaurus, but also compared it with modern seals; Hector ultimately named it Kekenodon, meaning seal tooth in combined Maori and Greek. Kellogg considered Kekenodon to likely represent a basilosaurid in his 1936 monograph, and Mitchell (1989) generally agreed, but noted the teeth were quite distinct and would necessarily represent a highly derived "dorudontine" - the cheek teeth trend towards having single roots with a trilobate cross-section rather than widely divided double roots, lack a cingulum on the lingual side of the enamel crown, generally more complex surface texture on the cheek tooth roots, and lower molars that have mesial cusps and critically lack this vertical groove called the 'reentrant groove'.
The holotype right frontal bone of Kekenodon onamata - the only non-earbone part of the skull that was preserved. From Corrie and Fordyce (2022).
