Hyaenondon (above), a creodont, used its rear-most teeth as carnassial scissors.
The males and females of most viverrids are about the same size, but where there is a
difference it is the female that is larger. One would have expected the reverse, at
least in those species such as the African Palm Civet where one male fights to monopolise
several females. Perhaps the sexes are usually similar in size because their need
to tiptoe along thin branches in pursuit of food made it impossible for males to become
bigger, and so fiercer. 
The African Civet's scent glands produce a valuable ingredient of expensive perfumes
From the fossil evidence, the teeth of the early Carnivores were very similar to those
of the African Palm Civet. This means that their food and social life were probably
also much like the African Palm Civet's. Despite its name, this African animal is
probably not a member of the palm civet subfamily, all of which are confined to Asia.
It has much sharper scissor teeth than true palm civets and, although its affinities
are still unknown, it may he closer to the true civet subfamily. Like most true civets,
African Palm Civets are primarily nocturnal foragers, gleaning prey as they meander
through the canopy, occasionally taking fruit in addition to a staple diet of small
vertebrates, eggs and insects. Except for fruiting trees, these food items are too
sparse to be shared, and once harvested, take a while to replenish. These disadvantages
to sharing a territory probably explain why African Palm Civets are solitary creatures.
An adult male occupies a territory of over 100 hectares (250 acres), and regularly
scent-marks trees along the border, and fruit-bearing trees within. Up to three females
live within a male's territory, each with her own plot of ground shared only with
the male and her sub-adult daughters. Other males, perhaps adolescents, squeeze into
the territory but maintain a low profile. Male and female African Palm Civets socialise
only rarely, seldom foraging in the same tree, doubtless to avoid getting in each
other's way. However, they keep track of one another through eerie siren-like calls,
sometimes peftormed as a true duet.
The Genet lives today much like some of the earliest cat-branch Carnivores
Most other viverrids are also primarily nocturnal foragers, but only snippets are known
of their tastes. The Feline Genet, for example, raids birds' nests. Forest Genets
lurk in cave mouths to swipe passing bats as they leave their roosts, and then meander
off to feed on the sweet nectar of bat-pollinated trees. Common Palm Civets are partial
to a drop of toddy, the juice tapped by people over much of southern Asia to ferment
as palm wine. Their drunken habits have earned these civets the popular name Toddy
Cat. Amongst the 34 other foods Toddy Cats have been recorded eating in Java is the
fleshy husk of coffee beans. The civets expel the undigested kernels in their faeces
and, when collected and ground, these passaged beans produce, so it is said, the finest
coffee possible. Several civets, such as the Celebes Civet and Small-toothed Palm
Civet, eat a lot of fruit.
The Small-toothed Palm Civet forages in trees for small vertebrates, insects and fruit in Southeast Asia
Some of these foods might be more easily shared than the prey of strictly carnivorous viverrids.
For example, a civet living largely off tropical fruit could hold a territory in which
there are always at least some trees in fruit, each providing enough food for several
adults. In such circumstances a male might better maximise his offspring by holding
a territory with a mate and helping to tend their young. Unfortunately, insufficient
is known of viverrids' social lives to decide whether fruit-eaters are more gregarious
than those dedicated to less shareable vertebrate prey.
The arboreal Binturong of Borneo is unusual amongst Carnivores in having a prehensile tail, and because females are bigger than males
The most extreme size difference occurs in the Binturong, a type of palm civet in which females are reputedly 20 per cent heavier than males
and have rather masculine genitals. Binturongs have departed most from the usual viverrid
mould. They have a shaggy black coat, each hair tipped yellow or white. As a Binturong
climbs, its scent pouch drags on the branches leaving a perfumed smear said to be
reminiscent of cooked popcorn. In the trees, a Binturong's long prehensile tail acts
as a fifth limb, allowing it to walk upside down, using its forelimbs to pull fruit
to its mouth. Only one other Carnivore has a prehensile tail: the Kinkajou (see page
155).
Viverrids are often said to illustrate the ancestral Carnivore design of arboreal,
nocturnal hunters, that has been adapted by the other modern families. Yet viverrids
themselves have contenders for several Carnivore trades. For example, the African
Civet is a robust, 12-kilogram (26-pound), dog-like creature with an intimidating
mane patterned in dots and dashes. It is the only viverrid that, like the dogs, has
non-retractile claws. The Otter Civet of Southeast Asia and western Indonesia lies
in ambush for prey in water. It is adapted for an aquatic life with dense fur, long
whiskers and nostrils that open on to the top of the snout and can be closed, as can
the ears. It also has dual-purpose dentition. Its premolars are unusually large, and
sharp and blade-like to cope with slippery fish and frogs. Its molars seem to be from
a quite different animal, being flattened to pulverise molluscs and other shellfish.
The
three species in the Madagascan subfamily, the Fossa, Falanouc and Fanaloka, are particularly
diverse. This is because the only other Carnivores sharing their island are some rather
weird mongooses, and the viveirids have adapted to roles that other Carnivores might
have filled had they been there. Apart from all lacking a scent pocket and being very
rare, the Madagascan trio have little in common. A 20-kilogram (44-pound), flat-footed
tree-climber with partially webbed toes, the Fossa is so like a cat that it was previously
misclassified as one. Its diet includes 10-kilogram (22-pound) lemurs, which are probably
the biggest prey taken by any viverrid. Perhaps the most extraordinary thing about
the Fossa is that females show genital mimicry of males -- that is, they appear to
have penises. Fossas indulge in marathon copulations, sometimes lasting 165 minutes,
with the male gripping the female's neck throughout. The second Madagascan viverrid,
the 4-kilogram (9-pound) Falanouc, most closely resembles a badger, having an elongated
snout and body, and non-retractile claws. It feeds mainly on invertebrates. The 2.2-kilogram
(5-pound) Fanaloka looks more like a fox, has retractile claws and feeds primarily
on small mammals, reptiles and amphibians.
The Madagascan Fossa's skull (left) reveals teeth that are
remarkably like those typical of the cat family
Before
the appearance of the modern families, the dog-branch and cat-branch evolved separately
in the New and Old Worlds, respectively. However, by the early Oligocene, 30 million
years ago, This tidy partitioning was shattered. The Bering landbridge opened up between
America and Eurasia, and representatives of each branch crossed. Although the true
dogs remained in North America until about six million years ago, other dog-branch
families became more common in Eurasia than in America. Most cat-branch Carnivores
remained in the Old World, but the true cats subsequently crossed to America. The
two branches of the Carnivores soon came face to face and, as will become clear in
the following chapters, their meetings were often as explosive as encounters between
modern cats and dogs!
Evolution had also been continuing in parallel in the northern and southern hemispheres
while their continents drifted as islands apart. By the late Miocene, seven million
years ago, all the modern families of Carnivore had arisen in North America and Eurasia.
The basic types of Carnivore we know today all existed, although no modern species
were on the scene. In the south, the marsupial marrimals were still the dominant predators.
The Fossa is actually a viverrid, but in the absence of catsDuring the long separation of north and south, a few species of mammal had crossed the divide, flying, floating on rafts or, perhaps, simply swimming with favourable currents in the seas that divided the continents. Few survived the journey, and even fewer bred once there, but in the millions of years that the continents remained separated, a tiny fraction were lucky. One of these was a North American Carnivore, Cyonasua, which made the crossing about 7 million years ago.
it has adapted to their trade in Madagascar
It was related to modern raccoons and coatis, and its name means dog-like coati.
The first individual may have been a pregnant female which scampered aboard a floating
raft of vegetation during a great flood in what is now Texas, only to find herself
washed up days later on a foreign shore. She would have found a world quite different
from the one she had left. Giant flightless thunder-birds ran down prey on plains
where huge camels grazed. Then, as now, omnivorous Carnivores like Cyonasua were adaptable.
She would have borne her young, and learnt to feed them on prey she had never caught
before and protect them from predators her forebears had never faced.
65
million years ago squirrel-sized Cimolestes developed the scissor-action teeth
that were to lead directly to the evolution of Carnivores.
These creatures and their descendants flourished for 5 million years in South America.
The idea that a handful of wayfarers could found a whole dynasty is awesome, yet there
is evidence of this occurring even in the history of humans. From the genetic similarities
between human populations, scientists estimate that fewer than 100 of our ancestors
colonised Eurasia from Africa and, subsequently, only 10 crossed to North America
to found the native peoples there.
One of Cyonasua's descendants was the size of a Giant Panda, the gentle giant,
Chapmalania. Its sheer size and strength were probably enough to protect Chapmalania
from the pouched and beaked killers, whilst it grazed on fruits and shoots. Sadly,
neither Chapalmalania nor any of the pioneering Cyonasua's other descendants survive
today. They were wiped out in an event that changed their world irrevocably and devastated
their southern contemporaries, the Pouch-knives.
The marsupial Pouch-knives of the south had almost perfect doubles in the northern
hemisphere: the sabre-toothed cats such as Smilodon (whose name means 'knife-tooth').
The two groups were completely unrelated and their uncanny resemblance illustrates
the pious idiom that there is only one way to do a thing, and that is the right way.
The Pouch-knife and Smilodon filled similar niches on their respective continents
and developed similar adaptations to succeed at their trade. These two sabre-toothed
predators stood on either side of the divide, like mirror images, as the two Americas
drifted closer.
Miacids were the first Carnivores, and used the fourth upper premolarsTwo million years ago, volcanoes welled up from the ocean bed and pushed their way to the surface in a line from North to South America. First as stepping stones, then as a bridge, they formed a Central American landcrossing between the two continents. For the first time since the break-up of Pangaea, there was an easy way for animals of the northern and southern continents to meet. At first the creatures of north and south seemed evenly matched. A couple of dozen genera of yankee animals invaded the south, and a dozen southern genera penetrated north. This ratio was roughly proportional to the sizes of the two faunas and so represented a fair swap. However, it was the yankee invaders that thrived. The North American incomers have generated many more species in South America than have the original residents, and the latter have suffered more extinctions. As a result, half of all mammal genera in South America today are descendants of the early yankee invaders. In stark contrast, only armadillos, opossums and porcupines from the original southern immigrants remain in North America, and even they have not diversified much.
and first lower molars as carnassial scissor teeth, therby leaving their
rear-most molar teeth free for other roles.
The great interchange of species between
the Americas clearly turned into a rout. The sabre-toothed cats obliterated the Pouch-knives.
Before the Central American isthmus rose up, not a single member of cat, dog, bear
or weasel families had set foot on South America. Soon that continent was supporting
more species of dogs and cats than any other. Many types of opossum fell in the face
of these incomers. Although a true Carnivore, the early settler Chapmalania was ousted
by bears that crossed the landbridge. A thunder-bird, Titanis, did invade North America
and lived for a while in Florida before becoming extinct, but the rest of the thunderbirds
down south were wiped out.
The teeth of the Common Palm Civet or Toddy Cat are very like those
of the first Carnivores. Its staple diet is small vertebrates, insects and
eggs, supplemented by fruit
More recently, history has repeated itself. Meddlesome humans introduced Carnivores
to Australia, producing a similar effect on the local marsupials to that of the great
interchange in South America. Nonetheless, some pouched killers still hang on there.
The Tasmanian Devil was probably ousted from mainland Australia by the Dingo, transported
there by people 8000 years ago. The Devil still survives in Tasmania, an island never
reached by the invading dogs. This sturdy 5-9-kilogram (11-20 pound) scavenger also
hunts small mammals. In the past, it probably fed on the leavings of the much larger
Tasmanian Wolf or Thylacine, which became extinct on the mainland about 3000 years
ago, again through competition with the Dingo. The Thylacine was decimated in Tasmania
in the early part of this century by bounty hunting and perhaps by disease, and has
not been definitely sighted since the 1930s. The quolls are probably the fiercest
of the surviving predatory marsupials. Their likeness to polecats led them to be called
'native cats'. The Eastern Quoll's range has decreased in recent years: this is attributed
to competition with Red Foxes introduced in 1871 for sport and in a vain attempt to
control the rabbits Europeans had introduced earlier.
Australia also had a candidate at one time for the King of Beasts, the Marsupial
Lion Thylacoleo, which bowed out about 10,000 years ago. The 1.25-metre (4-foot) long
Thylacoleo stemmed from a line of dedicated vegetarians and its nearest surviving
relatives are the phalangers, endearingly cuddly, forest-dwelling fruiteaters. However,
there was nothing at all cuddly about the Marsupial Lion. Unlike the Pouch-knives.
Thylacoleo had made the carnassial connection: its scissor teeth were as finely engineered
as those of a true Carnivore. In addition, these carnassials were embellished with
serrated borders. Its canine teeth were adapted to exert a choking grip, and it also
had huge claws on the inner edge of its forepaw's. This adept tree-climber preyed
on ground-dwelling kangaroos. Probably, like the modern Leopard, it dragged its prey
into trees and out of reach of its scavenging contemporary, the Tasmanian Devil.
Scientists have tried to explain why pouched killers put up such a poor show against
the Carnivores. Their limb proportions indicate that the extinct pouched killers were
slower than their Carnivore counterparts, but it is hard to believe that they could
not have evolved longer limbs if that was what was necessary to compete successfully.
One possibility is that the early denizens of South America were less beset by evolutionary
catastrophes, such as climatic changes, than were their contemporaries in North America.
Consequently the yankee victors were of more vigorous stock and had been, as palaeontonologist
Stephen Gould put it, 'tempered in a hotter evolutionary furnace'. However there is
no evidence to support this otherwise appealing hypothesis.
As with the demise of the creodonts, the most promising proposal relates to teeth.
The pouched killers, like modern marsupials, had no milk teeth. Milk teeth allow placental
mammals to swap their infant teeth for a new set suited to the needs of adulthood.
Young Carnivores have milk carnassial teeth, which are jettisoned when the permanent
scissor teeth erupt. The molars to the rear are then used for other purposes (as in
the dog family) or reduced (as in the cat family). In contrast, the ancient pouched
killers opted for a sort of molar conveyor belt: molar teeth erupted in turn, each
taking on the scissor role before being pushed forwards in the jaw by the eruption
of the next molar in the sequence. Thus, all the molars in the mouth of a pouched
killer started as scissors, and none was free to develop other functions. So, like
the creodonts, the pouched killers probably had to specialise in carnivory. The Carnivores,
though, could adjust their diet when circumstances changed, a flexibility that may
stem partly from their adaptable molar teeth.
Among more recent contenders, the creodont Hyaenodon, of 20 million years ago,
could probably do everything a Lion does today, and some assert that the extinct Dire
Wolf of 5 million years ago was more intelligent than any living Carnivore.
The problem facing predators, and all creatures, is that the rules of the game
change with time. Being the fastest, smartest or strongest only helps during phases
when the rules favour these qualities. Today's Cheetah is the fastest land mammal,
yet fares very badly in competition for prey with the markedly slower Spotted Hyaena
and Lion. Indeed, a slight shift in the African climate could favour longer grasses
that would put the Cheetah out of business. If the new were always better than the
old, then a modern Lion transported back in time 20 million years to the era of the
first big cats might be expected to do rather well. In fact, the prey at that time
were mostly giant herbivores, which would have dismissed the modern Lion with a kick.
But they had good reason to fear the slow yet powerful sabre-toothed cats whose teeth
were custom-built for slicing thick hides. While the Lion's conical canine teeth are
well-suited to tackling the grazers of today, it is likely that sabre teeth will once
more be in vogue if thick-skinned herbivores ever dominate the world's grasslands
again. Unfortunately conditions do not change predictably, so we cannot foretell the
shape and form of the predators that are to come.