The Science and Narratives of the art

I always try to inject some science and imagination into my palaeo-art. Here are some of my pieces stories, and the reasons I choose this direction.

International Taniwha           The Only Marine Dinosaur          Stormy Cretaceous Sea

Rare Marine Treat                 Elasmosaur Generalist part 1       Orca of the Oligocene

Triassic Giants                      Oceans of Zealandia                       Kaiwhekea

First Taniwha                        First Great Predator                        Once Upon a Claw

The International Taniwha 2012

While the most famous mosasaur is probably Tylosaurus, recent fossil finds are showing that it was in fact a regionally isolated beast that was local to probably just the inland sea of North America during the late Cretaceous.

During this same time a similar, but slightly different relative of Tylosaurus roamed the Central and Southern Pacific oceans. Originally found in New Zealand, and named after the local Maori's word for monster, Taniwhasaurus is turning out to be a very wide spread and important top predator of the late Cretaceous and was much more widespread than Tylosaurus.

Taniwhasaurus remains have so far been found in New Zealand, Antarctica, and Japan. However based on this distribution there is a distinct possibility it will turn up in the Northern Pacific as well. Making it the potential lord of the Cretaceous Pacific!

So here's to Taniwhasaurus, the new name in mosasaurs you should be getting to know...

Here I've depicted one swimming in the cooler waters of Zealandia (the prehistoric continent of which only New Zealand remains unsubmerged today). While there is no direct fossil evidence of kelp in Cretaceous New Zealand, it was further south than at present, and would have been cold for Cretaceous times. A possible ideal zone for cold water loving kelp.

 

The ONLY true marine Dinosaur 2012

A Hesperonisid, a toothed bird of the Cretaceous. As it still has teeth, there could be a slight argument it is not yet quite a true bird and just barely still a Dinosaur, but only just (if you do consider this correct).

Given the popular notion that Marine Reptiles are somehow Dinosaurs, a quick reaction by many palaeo enthusiasts is to state no Dinosaurs ever lived in the water... So long as you don't count birds.

I for one have adapted my education spiel to state there was this one family of ocean dwelling Dinosaurs. Only just this one.

Note the big nasty salmon ancestor Enchodus also attacking the smaller fish swarm.

 

Stormy Cretaceous Sea 2012


This picture is based on an incredible photograph by Stefano Unterthiner. In this photograph a large group of King Penguins stopped dead in their watery tracks as a large male Orca surfaces right in front of them. The mood and atmosphere is makes it one of the most powerful images I have ever seen in my life.

In my version we see a similar scene 75 million years before Mr. Unterthiner's shot. In this time the Penguins are replaced with Hesperornoids and the Killer Whale a Tylosaurine mosasaur.

According to Mr. Unterthiner the Penguins were more cautious than afraid. Typically Orca's leave them alone in favour of seals. However in this scene I imagine the Hesperorniods are much more worried. Stomach contents of a Hesperornis in a Tylosaurus show that large Tylosaurines would quite happily have munched on a toothed sea birds given the chance. 

A Rare Marine Treat 2012

This piece is a slight modification on the findings of Pasch and May 2001. They discovered a Hadrosaur carcass that had ended up in a deep ocean environment off Cretaceous Alaska (it was probably a Edmontosaur, but as it was without a skull making definite identification was made impossible) . It was clear this animal had died on the land, and then been washed out to sea where it bloated and floated for sometime. What was really interesting were bite marks left by a scavaging large Mosasaur on the forelimbs and stomach of the Hadrosaur.

The suspected reason the Mosasaur had bitten the carcass in these odd mostly bone regions, was that its teeth and eating mechanics are not at all ideal for butchering a large meal. Most Mosasaurs, much like their relatives the monitor lizards and snakes, were built to catch and swallow prey whole. They were superbly adapted for this, but as a result they would have been miserable at dismembering anything they couldn't immediately swallow. In the case of this Hadrosaur it appears that the Mosasaur went for the arms as it could get some leverage grabbing the bone. Despite this, it was only able to cause minimal damage, and probably only got a minimal meal. It at some point moved its scavenging to the torso, where it appears to have managed to damage some of the ribs before puncturing the abdomen. As the gas that was suspending the Duckbill was trapped in its stomach this puncture was probably what sunk the body.

I have recreated a similar scenario here, but with a slightly more intact Hadrosaur of a different genus. Most bloated Hadrosaurs (a common way to find them whether in fresh or salt water environments) are found without their heads. This appears to be a weak spot in duckbill anatomy when it comes to water based decomposition. I however have kept the head on my carcass here as this made the piece easier to understand. I may revisit this concept and try a more decomposed Hadrosaur in the future.

Elasmosaurs- Unexpected Generalists of the Cretaceous 2012

Traditionally Elasmosaurs, very long necked Plesiosaurs, have been seen as specialist fish eaters. However an examination of specialist species in Cretaceous oceans shows a trend for these to go extinct relatively quickly compared to generalists. Elasmosaurs thrived relatively unchanged for nearly the whole of the late Cretaceous. How was this possible if they were specialists?

The answer, based on new evidence and fossil finds, is that they were very unusual (but very successful) generalists.

One of the most interesting finds was in Australia, published in C.R. McHenry, A.G Cook, and S. Wroe, 2005, in which two specimens of Elasmosaur were found with shellfish clearly in their gut contents.

This at first seems ridiculous in face of their long necks and long interlocking teeth. How would they catch bottom dwelling shellfish that alone break them open?

This provides an excellent explanation for the rocks or gastroliths Elasmosaurs typically had in their stomachs. These stones were originally thought to be a form of ballistic, that allowed the Elasmosaur to stay under the water. However studies have shown that these rocks in the tummy would only have countered 10% of the Elasmosaurs weight. Not very good ballast in other words. However the rocks obviously served a purpose, and that appears to have helped them eat. Much like other reptiles (and birds) who swallow stones.

Instead of using their teeth to break open the hard shells, if an Elasmosaur simply swallowed the shell whole the rocks would act just as well as teeth for getting at a good seafood snack!

As for Elasmosaur teeth, while yes being ideally long, sharp, and interlocking for catching fish they are surprising robust when you look at them. Additionally their tight spacing for this interlocking made them an excellent secondary basket like structure on the bottom jaw, if gently run through soft sediment would act as a good catching point for shell fish.

So for this piece I wanted to illustrate how while there were shellfish specialists living beside Elasmosaurs in the form of the Mosasaur Globidens, the long necked Plesiosaur was undettered and made PART of its living off the same resource, and this helps explain how Elasmosaurs existed for so much longer unmodified than any other marine reptile of the late Cretaceous...

More parts of this series to come!

 Squalodon: Orca of the Oligocene 2012

We return once again to prehistoric New Zealand, still in the form of the continent Zealandia, but only just. By Oligocene 25 million years ago, the majority of Zealandia had sunk below sea level, and was not to resurface again. Not that this effected sea life adversely. In fact rather the opposite. Due to the remaining elevation provided by the sunken continental landmass (compared to the off self sea floor) Zealandia provided the basis for a large swallow sea during this time.

This supported a vast array of sealife. comprised of types we're familiar with today. Only much more primitive and ancestral forms. Among these were penguins, which had been thriving in the Southern oceans since the KT extinction event. These early Penguins were much more gracile then those we know today, as the Antarctic was temperate at this time.

The expansion of the Southern Ocean around Antarctica during this period was creating a vastly new and dynamic ecosystem to form with the strong currents that started to whip around the continent stirring up large quantities of nutrients. The drastic increase in avaliable food caused a major radition of Whales in the south.

Among these were the somewhat terrorifying Squalodons, or "Shark Toothed" dolphins. Some of these animals grow to nearly the length of the modern Orca, and would likely have preyed on most medium sized animals it encountered (though fossil evidence has yet to be presented).

Despite its large size and furious desposition, the Squalodon was not the appex predator of these swallow Zealandia seas. A far bulkier 9 metre ancestor of the Great White Shark prowled these waters, and most likely would have preyed on (young at the very least) Squalodons.

Triassic Giants 2010

This piece is an art tribute to the late Betsy Nicholls, former curator of Marine Reptiles at the Royal Tyrrell Museum. She is most famous for her collection and description of the largest yet known marine reptile Shonisaurus sikanniensis. However I will best remember her as a friendly and enthusiastic spokesperson for her science and the topic of marine reptiles. I only wish I'd had a chance to get to know her better.

I was fortunate to have been able to talk to her after her last (or so I'm told) public address. During this discussion the topic of Shonisaurus feeding came up. Dr. Nicholls was of the firm belief that the adult (toothless) animals were somehow feeding on cephalopods. So it was in this direction I took my piece.

Here a small pod of Shonisaurus sikanniensis plunge into a school of Belemnites. Whether they have dived to extreme depths in the daytime or are simply catching them at night is up to you the viewer.

Oceans of Zealandia 2009

Welcome to Cretaceous New Zealand, 69-70 million years ago. At this time New Zealand was part of a much larger land mass, a proper continent, half the size of Australia called Zealandia. By this time Zealandia was well in isolation from the rest of the world, having drifted away from Gondwana 83 million years ago. It would remain a giant landmass till well after the Cretaceous, but due to its lack of elevation and straddling a very active tectonic zone, Zealandia would eventually sink into the ocean leaving only the scattered remnants of many islands from its entirety. Of these Pacific islands today New Zealand is the largest.

Off the shores of Zealandia we see a school of Belemnite swarm near the surface of the newly expanding Tasman sea. This activity attracts many medium level predators, the Cryptoclididae Kaiwhekea. The commotion caused by this level of the food chain attract even higher up predators that lurk on the edge of the school awaiting an opportunity. In this snap shot, one can just make out the silhouette of a rather large shark that has momentarily broken its cover.

For this piece I wanted something of an overall introduction to this ecosystem community, which included the food-chain ratios somewhat to proportion. I'd also like it noted that I'm not attempting to imply or convey social behaviour on the part of Plesiosaurs (in particular Kaiwhekea), but that rather like in nature large gatherings of prey would attract large numbers of their their predators.

The Squid Eater (Kaiwhekea) 2009

One of New Zealand's most spectacular and complete vertebrate fossil finds has to be the single type specimen of the Cryptoclidid Kaiwhekea. This short necked Plesiosaur is among the most unique of the whole group. For despite being one of the last of this group of marine reptiles from around 70 millions ago, it is surprisingly primitive and has a great deal in common with Jurassic forms.

The formal name Kaiwhekea means "Squid Eater" in the indigenous language of the Maori, and it is a very appropriate name. The skull of Kaiwhekea is superbly adapted to hunt and catch mid sized soft bodied prey. The jaws are lined with hundreds of small needle like interlocking teeth, and powered by strong muscles to snap the mouth closed quickly. Its eyes were large set far forward in the skull, and were most likely binocular in vision.

This scene here is based on the conclusions of Kaiwhekea's description, and the remains of fossil Belemnites from the same locality as its skeleton Shag Point (Shag being the local word for Cormorant birds... not what most people think. Though I still laugh every time I drive by the villa's sign!)

Taniwha of Prehistory 2009 

Despite their fossil remains not being as complete as Kaiwhekea, New Zealand is known to have supported a vast and diverse array of Mosasaurs during the late Cretaceous some of which no doubt acted as the top of the food chain. Among the larger ranger of these marine reptiles was the Tylosaurid Taniwhasaurus. Known from the rear portion of the skull, this carnivore's jaws would be 3/4 of a metre long and had a body 10-12 metres long.

In my piece we see the Mosasaurid ambushing a young Kaiwhekea as it tried to catch squid. The nature of Mosasaur jaws means this is the largest marine reptile prey a Mosasaur could catch.

Mosasaur in the top of their mouth had a built in mechanism that do not allow prey to escape being swallowed, meaning they (like snakes and monitor lizards) had to swallow their prey whole. If like in TV shows and sensational media they attacked full grown adult prey animals they'd choke and die.

The First Great Predator 2009

An Anomalocaris plunges into a swarming school in the water high above the Burgess Shale. Despite its size advantage and the inherent speed this would grant it, the Anomalocaris still must work to snatch one of these active swimming creatures from the school. These other animals include the small enigmatic Nectocaris, common Canadaspis, and the large Odaraia.

The inspiration for this piece was a desire to see an active depiction of Burgess life. Life in both senses, the organisms and how they lived their lives. Normally pictures of the Burgess Shale tend to show small numbers of these animals in relatively calm subdued interactions (sometimes due to philosophic beliefs about primitive life, as discussed by Gould in Wonderful Life, and others for visual simplicity to not overwhelm the viewer). I wanted something that felt like a still from a nature documentary, and also told a story.

Once Upon a Claw 2009

More than 90-95% (probably more like 98-99%, but I'm no expert) Anomalocaris fossils come in the form of shed, molted, or broken off pieces of them. Most of these being their large clawed tentacle like arms. With such an abundance of these being preserved in the fossils record, to me, this suggests they were quite a common occurrence on the sea floor of the Cambrian.

Since early life wasn't smothered to extinction in these discarded claws, it stands to reason that they must have served some sort of positive ecological role to Cambrian reefs. This piece is how I envision such claws being assimilated and utilized by Cambrian communities. A illustration to the powerful irony of nature, one day your the greatest killer around and the next your the greatest giver of life!