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Today’s post concerns an unlikely ally—an eccentric friend you have most likely maligned (perhaps even to the point of death).  How eccentric is this unknown benefactor?  Well let’s just say our little comrade has up to 30 legs and likes to run on the ceiling—so, pretty eccentric.

No! The Italian soccer team is creepy and has many legs but it doesn’t run on the ceiling and it isn’t our friend.

I’m talking about the common house centipede (Scutigera coleoptrata), a myriapod which induces such unreasoning dislike in some people that I am going to avoid describing its extremely interesting physiology, habits, and origin, until after I have told you why you should not promptly step on it.  With its many hairy legs and its ability to swiftly scamper along smooth vertical surfaces, Scutigera has a tendency to alarm people into causing it mortal injury.  You should never do such a thing!  Scutigera is a relentless predator of bedbugs, roaches, termites, ants, silverfish, spiders, and fleas.  The house centipede is like a tiger to these truly annoying and dangerous vermin.  If you live in a large city it is entirely possible that your dwelling has been saved multiple times from horrible infestations by unloved house centipedes.

House Centipede (Scutigera coleoptrata) facing to the left of the page

Scutigera coleoptrata grows to be 25 mm (1 in) to 50 mm (2 in) in length.  They originally lived in the Mediterranean area, but they are successful and hardy and have quickly spread to all six temperate continents as humankind has moved around and built houses.  Scutigeras live up to seven years, so before you crush one, you might pause to reflect that it might have lived in your house longer than you have.

House Centipede (Scutigera coleoptrata)

You have probably seen a Scutigera running.  They move with preternatural agility and are capable of running upside down.  If you can divorce yourself from vertebrate-centric feelings of revulsion, you will see an amazing beauty to the rippling motion of their many legs.  They always remind me of little Venetian galleys or Byzantine dromons.  Like those warships, house centipedes are designed to be formidable. Perhaps we would appreciate them more if we saw the ninjalike grace with which they hunt.  They usually jump on their prey and sting it to death with modified front legs capable of delivering venom (evolutionarily unique appendages called forcipules), however they are very nimble and can also lasso smaller arthropods or whip them into submission with their many legs.  The forcipules of the house centipede are usually incapable of breaking human skin. If they do succeed in stinging a person (which they don’t undertake lightly–since we are the size of skyscrapers to them) the sting is usually no more painful than that of a bee.  Unfortunately a few people are allergic to centipede venom and can have dangerous reactions, so it is best not to handle them.

I said not to handle them!

Scutigera apprehends the world through compound eyes which can see visible light but are even better at viewing ultraviolet wavelengths.  Despite their acute vision, they tend to hunt with their long antennae which are extremely sensitive to both vibrations and smells.  Their elongated hindlegs have evolved to appear like antennae so that predators have a difficult time telling which direction a centipede will move in, but hopefully I have convinced you to leave them alone so they won’t have to run away from you. More house centipedes mean fewer bedbugs!

Man O’ War (Photograph by Enrique Talledo)

The Portuguese man o’ war (Physalia physalis) is not a jellyfish, in fact it is not a discreet animal at all, but instead a siphonophore—a colonial medusoid made up of specialized animal polyps working together as an organism.   These siphonophores have stinging tentacles which typically measure 10 metres (30 ft) in length but can be up to 50 metres (165 ft) long.  Being stung by a man o’ war does not typically cause death, but sailors and mariners who have survived the experience assert that it taught them a new definition of agony.

Glaucus atlanticus

But the fearsome man o’ war is not the subject of this post.  Instead we are concentrating on the animal which feeds on the man ‘o war (as well as other siphonophores which drift in the great blue expanses of the open ocean).  One is inclined to imagine that men o’ war are eaten only by armored giants with impervious skins and great shearing beaks (and indeed the world’s largest turtles, the loggerheads, are the main predators of siphonophores), however another much less likely predator is out there in the open ocean gnawing away at the mighty stinging colonies.   Glaucus atlanticus, the blue sea slug, is a tiny shell-free mollusk which lives in the open ocean.  The little nudibranch only grows up to 3 cm in length but it hunts and eats a variety of large hydrozoans, pelagic mollusks, and siphonophores (including the man o’ war).

Glaucus atlanticus eating velella colony animal

Although not quite as gaudy as its lovely cousins from tropical coral reefs, Glaucus atlanticus is a pretty animal of pale grey, silver, and deep blue with delicate blue appendages radiating out from its six appendages.  The little mollusks live in temperate and tropical oceans worldwide. They float at the top of the water thanks to a swallowed air bubble stored in a special sack in their gastric cavity. Because of this flotation aid, the slug is able to cling upside down to the surface tension of the waves.  Since it is entirely immune to the venomous nematocysts of the man o’ war, the sea slug can store some of the man o’ wars venom for its own use.   The tendrils at the edge of Glaucus atlanticus’ body can produce an extremely potent sting (so it is best to leave the tiny creatures alone, if you happen to somehow come across them).

Glaucus atlanticus inshore

Each and every Glaucus atlanticus is a hermaphrodite with a complete set of sex organs for both genders.  Incapable of mating with themselves they ventrally (and thoroughly) embrace another blue sea slug during breeding, and both parties then produce strings of eggs.  The hatchling nudibranchs have a shell during their larval stages, but this vestige quickly disappears as they mature into hunters of the open ocean.

A Smilodon fends off the vulture-like Teratornis at what would later be called the Rancho La Brea tar pits, situated in Los Angeles, California (Painting by Charles R. Knight)

Lately this blog has been fixated on magnificent saber-toothed mammals.  We have featured the extinct saber-toothed whale, a saber-toothed marsupial predator, the little saber-toothed deer, and even the familiar walrus (in reality, a giant saber-toothed seal), but we realize that everyone has really been looking forward to the most famous saber-toothed animal of them all, Smilodon, the saber toothed cat.  Smilodon was actually a genus of several large cats, the biggest of which, Smilodon populator, weighed 360 to 470 kg (790 to 1,000 lb) and was larger than modern tigers or lions. In fact Smilodon species are sometimes known as “saber toothed tigers” or “saber toothed lions,” however taxonomists tell us such names are off the mark since the Smilodons belonged to the extinct Machairodontinae genus of felines rather than the familiar Panthera genus of big cats so familiar today.

About two and a half million years ago, Smilodon evolved in North America from an earlier genus of saber toothed cat Megantereon (there were a lot of other earlier genera of saber-toothed cats, not to mention even more genera of saber toothed carnivores which were not exactly felines—the whole story is complicated).  During the Great American Interchange with South America the big predators invaded South America at the same time armadillos were making their way up into North America.  Yikes, that’s a pretty lopsided exchange.

In addition to long razor sharp teeth, Smilodons possessed immense neck and forelimb muscles. Using the muscles of their front torso they would pull down and pin the great grazing metafauna of the American plains.  Prey animals almost certainly included bison, tapirs, deer, American camels, and ground sloths. Additionally Smilodons might have opportunistically killed juvenile mastodons and mammoths. To dispatch such large prey Smilodons employed their fearsome canine teeth with which they bit through the prone creatures’ necks.

Smilodon fatalis (reconstruction/specimen at the Page Museum)

Paleontologists have collected a great deal of fossil evidence concerning Smilodons, which suggest that the big cats were sophisticates social predators like today’s lions or wolves.  The number and nature of saber-toothed cat fossils recovered from tar pits suggests that Smilodon prides would converge together on prey animals caught in the petrochemical ooze–only to become trapped themselves.  Also some fossilized smilodons have shown evidence of badly broken bones healing—a rarity in carnivores which is generally only possible for pack/pride animals which can (sometimes) rely on a support network.

Thanks to their size, ferocious appearance, and highly characteristic teeth, Smilodons have a special place in human culture to the extent that few other extinct animals do.  The Flintstones had a pet smilodon named “Baby Puss” which evicted Fred from his house in the title sequence and the moral struggles of Diego the saber tooth constituted the moral hook of “Ice Age” a cartoon movie. Ironically for all of our apparent fondness for the great cats, it seems that human migration into the Americas may have been the downfall of the great cats (which vanished 10,000 years ago) but whether their extinction was the result of humans overhunting their prey, shifting climate, or some other factor remains an open question.

Smilodon by Knight

Thylacosmilus digital illustration

I have always been fascinated by saber-toothed animals.  Only a few saber toothed creatures remain in today’s world (like the estimable walruses and a few tiny saber-toothed deer) but in fearsome ages past, the design was widespread.  Most readers are probably familiar with the smilodons, the magnificent saber-toothed cats which hunted the megafauna of Pleistocene North and South America, however the story of the saber-toothed cats intersects the story of another giant saber-toothed predator which was nearly as fearsome and even stranger. Thylacosmilus was a genus of saber toothed marsupial predators which ruled South America during the Miocene and Pliocene.  Like the smilodons, Thylacosmilidae were large, agile predators which used their long fangs to slash the throats of huge prey.  Unlike Smilodons, Thylacosmilidae were marsupials which gave birth to a tiny helpless larva which they then nurtured in a pouch.

Thylacosmilidae (artist unknown)

The prominent teeth of Thylacosmilus were a result of convergent evolution and the creatures did not share any direct ancestors with cats since the divergence of placental and marsupial mammals (deep in the depths of the Mesozoic).  Thylacosmilus’ teeth were also different in that they continuously grew throughout the animal’s life.  The teeth were probably worn down as the predators gnawed on bones.  Additionally Thylacosmilidae possessed scabbard-like bone flanges built into its lower jaw to protect its teeth (a feature missing entirely from Smilodons).  Who knows what sort of noises Thylacosmilidae made with these peculiarly shaped mouths? For millions of years Thylacosmilidae lorded over the strange mammals of South America.  The glyptodonts (and possibly other armadillos) developed their armor to ward off the mighty beasts.  However the fickle play of tectonics undid the mighty killers.

Thylacosmilidae and Smilodons were not closely related (click on this picture to visit "Understanding Evolution" an excellent site where I found this helpful image)

In the beginning of the Pliocene, a land bridge joined North America and South America and suddenly the true cats arrived on what had been an island continent.  As the climate dried out, Smilodons competed directly with Thylacosmilidae. Strange new herbivores appeared to displace the old prey animals.  The Great American Interchange of long sundered mammalian lineages proved too much for the saber toothed marsupials.  Thylacosmilidae were giant and fierce but they were no match for invasive cats.

Thylacosmilus atrox (digital art by viergacht)

To borrow a page from the timeless style of Sesame Street, this week Ferrebeekeeper is brought to you by the Roman letter Q.  Each post will concern a topic which begins with that rare letter.  So quench your thirst with quinine water and wrap up in a quaint quilt. There is a reason that the letter Q is worth 10 points in scrabble but I think we can find 5 relevant topics that are not too quixotic (also I’m going to stop using extra q words for effect immediately—please don’t stop reading).

A Northern Quoll (Dasyurus hallucatus)

For the first q-themed post, we must travel to the ancient arid continent of Australia. For reasons of geology and tectonics, Australia has been a wallflower in the great continental ballet and has been isolated for the last 40 million years.  Thanks to this geographic seclusion, the animals of Australia are much different than the creatures which flourish elsewhere, and Austalia’s mammals are dominated by marsupials like the kangaroos, the wombats, the koalas, and the bandicoots.  All of those creatures are herbivores, but there are insectivorous marsupials (like the numbat) and there are marsupial carnivores which prey on the others.  Some of the larger orders of marsupial predators have died off as Australia dried out, but a major order of predators remain–the catlike quolls.

Quolls (genus Dasyurus) are solitary, nocturnal mammals which seek shelter in their burrows and dens by day and hunt birds, amphibians, reptiles, and small mammals at night. They are agile all-terrain creatures capable of swiftly moving across the forest floor or through the forest canopy.  Quolls kill their prey with a bite to the neck where it joins the head.  In addition to being predators, they also scavenge for carrion and they can sometimes be found by picnic areas and rubbish dumps. There are six species of quolls which range in size from 350 grams (12 ounces) to 3.5 kilograms (8 pounds). Four species are located across the Australian mainland while one species inhabits New Zealand.  One outlier species, the Bronze Quoll (Dasyurus Spartacus) lives in the savannah of New Guinea. The animals all share a characteristic spotted fur coat and a similar lifestyle.  The closest relatives of quolls are the formidable Tasmanian devils (the largest extant marsupial carnivores) and the superficially weasel-like mulgaras.

Unfortunately, quolls are not doing well.  Feral cats, dogs, and foxes are much more deft predators and are outcompeting the quolls or eating them outright (although the quolls do get some free meals from the invasive wave of rabbits and rats which have swept Australia).  Additionally the quolls are falling victim to an even stranger invasive species.  The Cane Toad (Bufo marinus) is a toxic South American toad which was brought to Australia in order to control agricultural pests.  The toads secrete a powerful toxin which is potent enough to kill a human (some people ingest cane toad secretions in order to experience the hallucinogenic effects).  Cane toads resemble some of the natural amphibian prey species of quolls and the spotted predators eat them voraciously—only to fall sick and die.  In order to save the unlucky quolls, a project is afoot to train the predators not to eat cane toads. Wildlife researchers have been dropping small sausages made of cane toad from airplane in quoll habitats.  It is hoped that quolls will eat the sausages and become violently sick (but not fatally so).  Having had a miserable bad trip, the quolls will then presumably forbear from eating further cane toad flesh.

The Cane Toad (Bufo marinus)

One of the delightful things about the hymenoptera—the wasps, bees, ants, and termites—is that many different species remain unknown to science.  There are times when it seems frustrating to live in a world where most life forms have been categorized and collected, however the fact that some of the hymenoptera make their homes in the most isolated tropical wilderness means that vividly distinctive (and hitherto unknown) bees, wasps, and ants are found from time to time. Last week an entomologist exploring the remote rainforests of Sulawesi discovered a new species of immense predatory wasps with jaws longer than its front legs. The predatory wasp is shiny black with evil gothic barbs running along its abdomen.  Although the wasp’s habits and behavior are still unknown, its size and its formidable jaws would seem to indicate that it is a predator.

Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at the University of California, Davis, discovered the wasp as part of a biodiversity expedition to the remote forests of Sulawesi.  She plans to name the wasp after the Garuda, an eagle-like divine being from Hindu legend which is associated with speed and martial prowess (and with the constellation Aquila). The Garuda is admired and known in many different myths from Southeast Asia but it is particularly associated with Indonesia—and has become something of a national symbol

The Garuda

Sulawesi, the fourth largest island of Indonesia has long been an ecological treasure trove thanks to multiple isolated peninsulas (complicated geology has given the island has an unlikely shape), impassible mountains, and huge wet forests located only a few degrees from the equator.

Sulawesi

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