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KONICA MINOLTA DIGITAL CAMERA

KONICA MINOLTA DIGITAL CAMERA

Ferrebeekeeper has written about the giant otter, the largest extant mustelid (which is an alpha-predator of the world’s largest river).  But what about extinct mustelids?  Honey badgers, wolverines, ferrets, and, yes, giant otters, are fearsome animals: was there once a giant honey badger or a huge super-wolverine?

Yes.

The  Megalictis lived in North America during the Miocene.  It weighed as much as a small black bear—somewhere between 50 and 90 kilograms (100—200 lbs), but it had a body (and presumably a temperament like a wolverine or a badger.  Indeed, the picture I have in my “Prehistoric Mammals” coloring book (thanks, Dover!) makes it look exactly like a giant honey badger.

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I wish I could tell you more about Megalictis—where exactly it lived and how.  All we can say is that it was a predator…and not a lurking predator—it caught and subdued its prey by brute strength.  However we do not know why it flourished (although it evolved during the Miocene “cat gap” when North America was low on the most widespread and successful mammalian predator) or what led to its extinction.  Still search the internet and find some honey badger videos—then imagine if they were ten time larger! It is a formidable thought!

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Pebas 17 Ma

The Amazon River is the world’s largest river and it has the world’s largest drainage basin—the vast Amazon rainforest, which stretches from the Andes in the west, to the Guiana Highlands to the north and the Brazilian Highlands in the south.   The great river drains east into the Atlantic Ocean….but it was not always so.  Before the Andes Mountains rose, the river drained west into the Pacific.  Throughout the Cenozoic, the mouth of the river moved up around the continent.  Thirteen million years ago, during the Miocene, the river drained north into the Caribbean through a huge tropical swamp–the Pebas mega-wetlands–which covered over one million square kilometers of what is now the Amazon Basin.

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An illustration of Pebas Corocodilians–Gnatusuchus is underwater, gobbling clams (art by Javier Herbozo)

Like today’s Amazon Basin, the Pebas mega-wetland was a great riverine rainforest.  And yet the ecosystem was very different from what is there today.  The marshes and swamps were filled with bivalve mollusks that thrived in the oxygen-poor waters.  Predators evolved to feed on these clams and mussels…and what predators!  This is Gnatusuchus, a caiman with spherical teeth for crushing open shellfish. Can you imagine biting through the shell of a clam?  Just thinking about it makes my jaw hurt and my teeth feel broken.  Yet Gnatusuchus bit through heavy shells for every meal!

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A life-sized reconstruction of the gigantic Purussaurus

The crocodilian grew to lengths of 1.5 meters (about 5 feet) and had a short round shovel-shaped mouth to focus maximum force on biting through clams.  Life in the Pebas was not all basking and clam feasts for Gnatusuchus.  The reptile was hardly the only reptile in the swamp, but was instead one genus among a hyper-diverse group of crocodilians including giant toothy predators capable of eating Gnatusuchus.  One of these predators, Purussaurus neivensis grew to be 12.5 metres (41 ft) in lengt—making it a rival of the great Mesozoic crocodilians like Phobosuchus (maybe I should have mentioned this horrifying monster first, instead of alluding to him after the clam-eater, but Ferrebeekeeper is interested in mollusks and their predators not in giant crocodiles: this is not Peter Pan, my friend).  There were also piscivorous crocodilians with long scissor snouts foll of hooked teeth (like modern gharials), and even little crocodilians on stilt-like legs that ran around plucking up small prey in the manner of pipers or herons.

anatosuchus-size

Seven million years ago, the Pebas began to change from swamps to channels as Amazonian drainage became spread through an even more enormous basin. Still, the diversity of the creature that lived there became a heritage for the contemporary Amazon, arguably the most diverse ecosystem in the world today.

Livyatan Melvillei (image painted by Balazs Petheo)

Livyatan Melvillei (image painted by Balazs Petheo)

Behold the terrifying ocean monster, Livyatan Melvillei! This predatory toothed whale lived 12-13 million years ago during the Miocene epoch and grew to 13.5 to 17.5 meters (45–57 feet) in length. A large adult whale could have weighed up to 50 tons. The extinct megapredator is named for Herman Melville and for the Biblical leviathan (“Livyatan” is from the Hebrew word for Leviathan). The great whale’s family is currently listed as “incertae sedis” which means “status uncertain,” a taxonomical place-holder used when biologists are trying to ascertain a creature’s relationship to other related organisms within a larger order.

Livyatan Melvillei

Livyatan Melvillei with smaller baleen whale

In terms of body size, the modern sperm whale is probably slightly longer and heavier, but the livyatan had stronger jaws and much larger teeth. Paleontologists describe the mighty creature as having “the biggest tetrapod bite ever found,” which is no trivial matter, since the tetrapods include all mammals, reptiles (like dinosaurs), amphibians, and birds. Of course plankton feeders (like blue whales and whale sharks) have larger mouths, but the sperm whale and the livyatan have more powerful maws filled with large sharp teeth. The 36 centimeter (1.2 foot) long teeth of livyatan are the largest known teeth from the animal world which were used for eating (which is to say the tusks of elephants, walruses, Odobenocetops, and narwhals tusks were larger, but were not used for biting into plants or animals).

Livyatan Melvillei biting a smaller baleen whale (painting via dino-rider)

Livyatan Melvillei BITING a smaller baleen whale (painting via dino-rider)

Livyatan Melvillei presumably swam the deep blue ocean hunting for seals, dolphins, baleen whales and whatever other sea creature was large enough to command its attention (giant sharks, huge squid, huge fish, and bizarre giant birds?). Like the sperm whale it seems to have had a spermaceti organ in its head although it is unclear if this was used for echolocation, auditory signaling, or aggressive male sexual display (i.e. head-butting).  It must have been quite a (horrifying) sight to see one of these giant monsters biting apart a 10 meter (33 foot) long baleen whale. Sadly, the ever-changing dynamic of ocean life caused the great toothed whale to go extinct at approximately the same time as megalodon, the largest known shark (which was a contemporary of the great whale).  Numerous websites speculate which great animal would have won an ocean duel–which is foolish, since whales are clever animals and thus the obvious victor.

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Bullockornis (with human-size silhouette for comparison)

Bullockornis (with human-size silhouette for comparison)

My sincere apologies for being such a truant blogger last week!  Not only did I fail to post any new articles since Tuesday, I unpardonably left you stuck with nothing but the flimsy Ms. Perry during that time. In order to apologize, allow me to take you on a trip to the island continent of Australia…15 million years ago during the Middle Miocene. During this time one of the largest birds ever lived across Australia: a giant fowl named Bullockornis.

Bullockornis

Bullockornis

Bullockornis was a 2.5 meter tall (8 foot 2 inch) gooselike bird.  The creature weighed in at approximately 500 kilograms (1100 pounds) and scientists believe it was actually related to the modern geese and ducks.   If you have ever met a modern goose, you will realize that a goose the size of a bear would be a formidable creature indeed.  Additionally Bullockornis possessed a razor sharp beak with immensely powerful jaw muscles.  It is hard not to imagine the giant bird nipping off a he-man’s arms like corn kernels or biting through bridge cables with this monstrous beak, but the truth is scientists don’t know what the bird used it for.  The monstrous goose could have been a hunting carnivore (like certain ducks are today) or an herbivore which grazed on heavy dense plants.  Perhaps, like contemporary geese, it was an omnivore which hunted, grazed, and opportunistically scavenged whatever it could get.

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Bullockornis was discovered in 1979 but it only became well known when some PR savvy writer christened it the “Demon Duck of Doom”  (which strike me as a silly 1930s Disney-style name, but I guess whatever gets people involved in paleontology is good).  The scientific name “Bullockornis”  means “bullock-bird” but, even though the bird was the size of an ox, it is actually named for Bullock Creek (a rich fossil location in the Northern Territory).  Bullockornis was not the only giant of the Miocene in Australia.  The Bullock Creek fossil beds also contained fossils of Giant horned tortoises, marsupial “lions” (i.e. thylacoleonids) and grazing Diprotodontids—giant wombats (although nothing so large as the mighty Diprotodon which evolved in the Pleistocene).

Fossil Bullockornis Skull

Fossil Bullockornis Skull

A smew hunting underwater (by DianneB1960)

A smew hunting underwater (by DianneB1960)

The National Zoo in Washington D.C. has a duck pond over by the parking lot entrance.  There are numerous pretty North American ducks in the pond as well as mute swans from Europe, black swans from Australia, and various fancy ducks from around the globe–but these beautiful waterfowl pale in comparison to lions, pandas, and elephants–so visitors are inclined to rapidly push by the little lake.  One day (when I too was rushing by) I noticed a ghostly white presence flitting around the bottom of the pond.  At first I thought I was hallucinating and then I thought that a penguin or puffin had escaped the Arctic area.  It was an amazingly dexterous aquatic hunter swimming underwater hunting for small fish.  I watched for some time before it popped to the surface and revealed itself to be…a male smew!

Smew Drake (Mergellus albellus) from http://birds-ath.blogspot.com

Smew Drake (Mergellus albellus) from http://birds-ath.blogspot.com

Smews (Mergellus albellus) are the world’s smallest merganser ducks.  They may seem alien because, for modern birds, they are ancient. Fossils of smews have been found in England which date back to 2 million years ago.   The smew is last surviving member of the genus Mergellus—which includes fossil seaducks from the middle Miocene (approximately 13 million years ago).  Smews breed along the northern edge of the great Boreal forests of Europe and Asia.  During winter they fly south to England, Holland, Germany, the Baltic Sea, & the Black Sea.  Like other Mersangers, smews are hunters: they dive underwater and deftly swim down fish (showing ballet-like grace during the process).  Like many other sorts of piscivorous hunters, smews have heavily serrated beaks (which are further specialized with a wicked hooked tip).

Smew party (Norman McCanch, 2011, oil)

Smew party (Norman McCanch, 2011, oil)

The drake smew has been poetically described as having the combined appearance of cracked ice and a panda.  Female smew ducks are plainer—they have gray bodies, chestnut crowns and faces, and a white neck. Although smews are from an ancient lineage and live in a difficult part of the world, they are still not doing badly.  Their numbers have declined somewhat, but they are not endangered (which is good news because they are very lovely and captivating).

Obdurodon--A Miocene Platypus which flourished 15 to 20 million years ago

Ferrebeekeeper has an abiding interest in monotremes including both the poisonous platypus and the enigmatic echidnas (with their advanced frontal cortex).  But sadly that is about it as far as it goes for the extant egg-laying mammals: there are only two living families of monotremes (with a scanty total of five species split between them).  To learn more about these animals one must turn to paleontology.  Unfortunately even in the fossil record, monotremes are extremely rare.

Based on genetic evidence, biologists believe that the first monotremes made their advent in the history of life about 220 million years ago during the Triassic era; however the earliest known fossil monotreme so far discovered was a fossil jaw from the early Cretacious era about 120 million years ago.  The bones belonged to Steropodon galmani, which seems to have been a beaked swimmer about 50 cm (20 inches) long which lived in Australia.  Steropodon was apparently a giant among Cretacious mammals–most of which seem to have been shrew-sized (so as to better avoid attention from their contemporaries, the dinosaurs). Reconstructions of Steropodon all seem to resemble the platypus, and most paleantologists would probably concede that it was a sort of platypus—as apparently were other Mesozoic fossil monotremes such as  Kollikodon and Teinolophos (platypuses and these platypus-like forbears are called the Ornithorhynchida).  During the Cretaceous era, the land which is now Australia was in the South Polar regions of the world (approximately where Antarctica is today).  Although temperatures were much warmer during the Cretaceous, monotremes must still have been able to deal with terrible cold: it is believed that the extremely efficient temperature control and the deep hibernation mechanism which these animals continue to display first evolved during that time.

An artist's reconstruction of Steropodon

The only monotreme fossil which was not found in Australia was from another platypus-like creature named Monotrematus sudamericanum.  The creature’s remains were found in a Patagonian rock formation from the Paleocene era (the era just after the fall of the dinosaurs). Monotremes probably flourished across South America and Antarctica, as well as on Australia, but evidence is still scarce. There are most likely many interesting monotreme fossils throughout Antarctica, but, for some reason, paleontologists have not yet discovered them. Additionally, unlike the marsupials (which still quietly flourish throughout South America), the poor monotremes were wiped out on that continent.

Another artist's vision of Steropodon galmani--Notice how peeved the poor creature looks!

Last week I wrote about the Eocene era and the great proliferation of mammalian types which took place during that warm and fecund time.  Although most families of mammals alive today first appeared on the scene during the Eocene, obviously the monotremes were already incredibly ancient.  The Eocene does however seem to have been significant time for the monotreme order: the aquatic platypuses were apparently the ancestral monotremes, and echidnas (the Tachyglossidae) probably split off from them during the Eocene.  Unfortunately we have no Eocene monotreme fossils so this conclusion is based on genetic evidence and on the suffusion of Miocene monotremes which include representatives of both Ornithorhynchida and  Tachyglossidae.  Some of these latter creatures are spectacular, like Zaglossus hacketti the giant echidna from the Pleistocene which was about the size of a ram! As Australia dried up so did the monotremes and now there is only one species of platypus left…

The Giant Echidna (Zaglossus hacketti) which lived until 20,000 years ago...

Well, that’s a cursory history of the monotremes based on what we know.  I wish I could tell you more but unfortunately there is no fossil evidence concerning the first half of the order.  Sometimes I like to imagine the first monotremes—which were probably clunky, furry platypus-looking characters with an extra hint of iguana thrown in. These creatures fished in the alien rivers of the Triassic world in a time when dinosaurs and pterosaurs were also still evolving.

Turkeys have been widespread and successful since the early Miocene (23 million years ago).  Since their robust bones fossilize quite well, a number of extinct turkeys are known to paleo-ornithologists (including two genera which do not exist today, the “Rhegminornis” and “Proagriocharis”).

The best known of these vanished turkeys is the Californian Turkey, Meleagris californica, which died out about ten to twelve thousand years ago as the ice ages ended and human settlements became common.  The Californian turkey had a shorter beak and a stockier build than contemporary turkeys but it was a similar creature and probably shared many of the habits and vocalizations familiar to us.  Its remains have been discovered profusely in the tar pits of southern California, where it must have been preyed on by the great carnivores of that Pleistocene.  Californian turkey bones have also been found in camp middens of ice age humans, whose love of succulent turkey dinners may have combined with climate change to usher the poor birds to extinction.

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