Joseph McKee: They Grew ‘Em Big In Times Gone By

If you took a time machine back to the Pliocene Epoch, you would find sharks bigger than buses and birds the size of small aeroplanes.

Fossil expert Joseph McKee has found 3-million-year-old remnants of the giant shark, Carcharodon megalodon, and the bony-tooth bird, Pseudodontornis, among cliffs in south Taranaki. 

Models of the extinct creatures float in space over Puke Ariki foyer. Standing before the ten-metre shark replica, nicknamed Meg by staff, Joseph has a telling message: "That's only a youngster - mum was bigger."

According to shark scientists, a full-grown megalodon was between 13 and 17 metres long. To put that into perspective, a 50-seater bus is about 12 metres long and the maximum length of a modern great white shark is about 7 metres. "If you were going to be in the water say about three million years ago, you would have to be in something like the Cook Strait ferry to be safe. But if it [the shark] rammed the boat you would feel the boat shudder" Joseph says.

"You wouldn't want to go out in a little boat and go fishing like people do today" he says. "You wouldn't be protected - it would just crunch the boat like an empty Coke can. You would be a snack for a megalodon. A dolphin would have been a snack as well." Seals, whales, penguins and schools of fish would also have made up the megalodon's diet. "In a feed it would be eating several tonnes of fish or whale meat." The massive fish would then slip away to let the food digest in a stomach filled with concentrated acid. "It could digest bones as well as flesh."

In the early 1990s, Joseph found megalodon vertebrae in the sandy mudstones of the Tangahoe Formation at Hāwera. "The (two) best-preserved vertebrae measure 9cm and 11cm in diameter, much smaller than the largest-known C. megalodon vertebrae of 15.5cm in diameter from Belgium" he reports.

When scientists want to estimate how large a megalodon might have been, they err on the side of caution. Therefore, they must assume the fossil they have collected is the largest part of a shark's backbone - unless they have more evidence.

Working on this theory, the Hāwera specimens would have been 6.6 metres and 4.5 metres in length. But Joseph believes the sharks were probably double that - more like 13+ metres. He explains why. "The two [vertebrae] I have found are from the tail region." These are far smaller than those from the mid backbone.

Joseph is hoping to find a megalodon tooth. One of the largest in the world was found along the coast from Hāwera, near Whanganui - but not by the former Opunake lad, who was originally born in Northern Ireland.

The fossilised tooth measured 12cm high, more than double the size of a large tooth from the modern great white shark. Imagine a massive head filled with about five rows of huge teeth. As in great whites, a megalodon's front set would be the largest, with teeth varying in shape and size around to the sides. It probably shed teeth and grew new ones, just like its much-smaller modern counterpart.

"The great white gives birth to live young; probably the megalodon would have done the same," Joseph says. When in the uterus, the unborn pups would have also grown and shed teeth. "Their teeth are very, very different than the adults and juveniles" he says, explaining how these could confuse fossil hunters.

Joseph expects the new-born pups of a megalodon would have been between two and three metres long. "Even the youngest would have been something to have avoided."

All the theories about the megalodon are based on studies of great whites and other sharks. "The more we learn about the modern sharks, the more we find out about the fossil sharks - so it's a good reason to study them."

Taranaki historian and zoologist Ron Lambert says the Carcharodon megalodon roved the world's seas for 40 million years. "The giant megalodon shark, luckily, became extinct about a million or so years ago, probably because of the global cooling during the Pleistocene Ice Ages."

At the same time Meg was prowling the waters off Taranaki, the giant Pseudodontornis or bony-toothed bird was surfing the air currents. If you went back a little more than 3 million years, you may find yourself the victim of an unexpected downpour from the world's largest-known seabird. "Some people have experienced a seagull letting fly, but if this bird did, it would drench you in this fishy, smelly poo" laughs Joseph.

Look up (you can do this within Puke Ariki) and you would see the silhouette of a magnificent bird, with wings measuring about six metres from feather-tip to feather-tip. "That's double the size of an albatross," he says.

Fossils found in South Carolina in the United States relate to birds with wingspans measuring up to eight metres across. "You are looking at the wingspan of a small plane," he says.

Joseph's finds, which occurred in 1982, 1997 and 1998, are of great significance to the fossil world. "The oldest specimen is from England and is 54 to 55 million years old. The youngest is the stuff here, from Hāwera - so far."

The discovery of the south Taranaki fossils has extended the species' timeline from late Paleocene to mid-Pliocene (Waipipian age). The Hāwera specimens are also the only Pseudodontornis fossils found in New Zealand's North Island. In 1962, a school teacher discovered remnants of the soaring bird on the north Canterbury coast.

"Most of the bones I have found are humeri - they are the upper wing bone," Joseph says. "The bones are very big, but very light so when they are preserved, they tend to be crushed." Some of his fossils also reveal signs of a predator. "I suspect that they were chewed by sharks" Joseph says, unable to discern whether the birds were bitten dead or alive.

The number of bones found show between five and seven of the massive birds were coasting the skies off Taranaki - and way beyond.

"Their wings were very long and thin - a bit like a glider's wings," says Joseph. "They could take the air currents and go long distances. These birds could probably go around the Pacific or southern oceans - vast distances - and come back to a particular place to nest."

One of the most distinctive features of the now-extinct seabird was its beak, serrated with bony projections that looked like teeth. Unlike the teeth of mammals and the mighty megalodon, these 1.5cm high teeth could not be shed. "A bit like the tuatara - they are not real teeth, but projections of the jaw." Joseph says the bony-tooth bird used its saw-like jaws to grab and grip squid and soft-bellied fish from the ocean.

He grins at the thought of these huge birds wandering around today. "It would make it interesting down at the beach - your small dogs might be fair game." The palaeontologist has high hopes of finding a fossilised skull of a Pseudodontornis, but knows it's likely to be a specimen crushed flat by the forces of nature. "It's a matter of just being patient."

When he goes fossil hunting along the wild Taranaki coast, Joseph's green eyes seek brown against dark grey - the tell-tale signs that a rock is hiding something ancient, precious and mysterious. A skull and beak of a bony-tooth bird would measure between 65 and 70cm long, so would be encased in a long pod of rock (called a concretion).

Joseph, who has a PhD in biochemistry from Massey University, does his own acid etching to expose the fossils. This is a long and complicated process involving acid baths and tubs of water.

Remnants found in soft sediment can be revealed using hand tools. "You work away at it with a paperclip or a penknife or a metal scribe." If it's a bit hard, Joseph works on the rock with an air scribe (a mini jack hammer), wrapped with foam to stop the vibrations from hurting his fingers.

He has learnt these techniques by visiting overseas museums and seeing the experts at work in well-equipped laboratories. "Here we have got to improvise" he says. "I use everything from a paperclip through to concrete cutters."

While these fossil-revealing methods may sound hazardous, Joseph is a careful man - especially when scanning the cliffs from Ōhawe southwards.

"Because the cliffs are eroding, they are quite dangerous," he says. "Nine people have been killed along the coast over the years." Joseph follows his own strict rules to keep safe. He will only go a-hunting three hours either side of maximum low tide and never lingers too long beneath a cliff. "If you get a gut feeling 'this looks a bit dodgy', just move along."

If Joseph spies a fossil, he will stand back and study the cliff for potential slips and precariously placed rocks. "If it's too risky I leave it - there will always be another specimen that will turn up."

Other safety tips are to make sure you tell someone when and where you are going and how long you will be. Having a cell phone isn't enough, because the service often cuts out on cliff-lined coasts.

Joseph says fossil hunting is an ideal interest for youngsters, but they should always have an adult with them. "You can get nice specimens of oysters and clams" he says of the South Taranaki coastline. These fossils are found within round stones, which can be picked up and bounced. "They break in half easily, so you have the positive and negative [of the shell]. They are easier to collect from the soft sandstone."

People looking for larger fossils will need to consider how to move their finds. Joseph has turned drums into skids and pushed a wheelbarrow along the beach to collect his treasures. He also gets help from friends and family – “rocks don't have handles” - and has even arranged for helicopters to pick up large specimens set in stone. "A good guide for fossil collecting is, if your Mum and Dad can lift the rock it will fit in the car" he says.

Those sandstone cliffs have yielded an ark's worth of lost species. Baleen whales, dolphins, including a long-snouted type, seals, penguins, petrels and other birds, a variety of sharks, elephant fish and many other kinds of fish have been spotted and bagged by Joseph. He has also gone inland, scouring farmland and riverbeds for hints of New Zealand's past life.

His has two main pieces of advice for young fossil hunters. "Always go with an adult - that's the best way and they can always help carry the heavy rocks home for you!" And: "Always ask a farmer, before going on their land." Joseph says it's important to accept no for an answer - there will always be other farmers to grant you permission to roam their relic-ridden realms.

His own doggedness has paid off, especially in tracking even older species.

Step back into the time machine, fasten your seat belts - we're going back between 65 and 80 million years to the Late Cretaceous period.

Now you will be walking among dinosaurs - or running away from a T. rex-sized meat-eater. There were smaller meat-eaters to watch out for too - raptor size and smaller. Also, there were the much friendlier plant-eaters - large sauropods, the armour-plated ankylosaurs and the cute Hypsilophodontid dinosaur, Dryosaurus.

The plant-eating Dryosaurus had a horny beak and grinding teeth, walked on two legs and was as tall as an average 10-year-old child.

Only four people in New Zealand have found Cretaceous dinosaur bones - Joseph McKee, Trevor Crabtree, plus Joan Wiffen and husband Pont (now deceased). In late 1995, Joseph was hunting in the Mangahouanga Stream dinosaur site in the Hawke's Bay when he found a partial femur of a Dryosaurus. "That was quite exciting - I had been looking for so many years" Joseph says.

Dinosaur hunting in New Zealand is a difficult task because palaeontologists must trek over rugged terrain to isolated sites and then find ways to haul out big rocks.

"For the effort that you put in to find a dinosaur bone here, you could go to the Gobi Desert of Mongolia, China, Africa, the United States or South America and dig out complete skeletons" Joseph says. "We look overseas and think 'They've got it easy'."

However, he does believe that New Zealand's rock formations could hold unimagined treasures. About 80 to 90 million years ago, New Zealand separated from the massive land mass known as Gondwana. "We could have unique things here" he says.

With walking boots on, crowbar in hand, eyes as sharp as the New Zealand giant eagle, Harpagornis moorei (now extinct), Joseph could well be the one to find clues to a yet unnamed, uncharted, bizarre creature from our ancient past.