Originofthedog

The earliest fossil carnivores that can be linked to canids are the Eocene Miacids, some
56 to 38 million years ago. From the miacids, evolved the cat-like Feloidea and the
dog-like Canoidea carnivores. Most important to the ancestry of the dog was the canoid
line, leading from the coyote-sized Mesocyon of the Oligaene (38 to 24 million years ago)
to the fox-like Leptocyon and the wolf-like Tomarctus that wandered North America
some 10 million years ago. From the time of Tomarctus, dog-like carnivores have
expanded throughout the world.
There were significantly sized canid carnivores such as Hesperocyon gregarius. The
Hesperocyon was a slender. long tailed animal that inhabited the tropical rainforests of
North America (about 37 million years ago). The Hesperocyon hunted birds and their
eggs, eating seeds and fruit also. Another canid, Borophaginae, hunted larger animals
such as horses and camels. However, the Borophagines met an untimely end about 5
million years ago when the climate cooled and meat supplies began to dwindle. About 2.5
million years ago, the Borophagines became extinct. With the Borophagines gone, the
other branch from Hesperocyon, known as Leptocyon, began to thrive. The Leptocyon was
a slender, narrow-snouted carnivore whose teeth had no special bone crushing ability.
Leptocyons hunted smaller prey and used the back lower carnassial teeth to crush plant
matter. It was for this reason the Leptocyon survived and the Borophagine did not. In a
few million years, the Leptocyon split into a number of different species, leading to the
canid family tree: South American Zorros (foxes), wolf-like carnivores (coyotes, jackals,
wolves) and fox-like carnivores (red fox and its relatives).

Scientific Classifications

Domain:      Eukarya
Kingdom:       Animalia
Subkingdom:      Eumetazoa
Phylum:      Chordata
Subphylum:      Vertebrate
Class:       Mammalia
Subclass:       Theria
Order:         Carnivora
Suborder:          Caniformia
Family:       Canidae
Subfamily:      Caninae
Tribe:      Canini
Genus:       Canis
Species:      C. lupus
Subspecies:       C. I. familiaris
Trinomial name:
Canis lupus familaris

In 2008, an international scientists released findings from an excavation at Goyet Cave in Belgium declaring that a large, toothy
canine existed 31,700 years ago and ate a diet of horse, musk ox and reindeer. Prior to this Belgium discovery, the earliest
modern dog fossils were two large skulls from Russia and a mandible from Germany, that dated from roughly 14,000 years ago.
Remains from smaller dogs from Natufian cave deposits in the Middle East, including the earliest burial of a human being with a
domestic dog, have been dated to around 10,000 to 12,000 years ago. There is a great deal of archaeological evidence for dogs
throughout Europe and Asia around this period and through the next two thousand years (roughly 8,000 to 10,000 years ago), with
fossils uncovered in Germany, the French Alps, and Iraq, and cave paintings in Turkey.
Genetic analysis indicate all dogs are likely descended from a handful of a small number of founding females, although there is
evidence that domesticated dogs interbred with local populations of wild wolves on several occasions. Data suggests that dogs first
diverged from wolves in East Asia and that these domesticated dogs then quickly migrated throughout the world, reaching the
North America continent around 8000 B.C. The oldest group of dogs, which show the greatest genetic variability and are the most
similar to their wolf ancestors, are primarily Asian and African breeds, including the Besenji, Lhasa Apso, Alaskan Malamute and
Siberian Husky.
Systematic analyses of dog genome has revealed only four major types of dogs that can be said to be statistically distinct. These
include the "Old world dogs" (e.g. Malamutes and Shar Pei), "Mastiff-type (e.g. English Mastiff), "herding-type" (e.g. Border
Collie), and "all others" ( also called "modern"- or "hunting"-type).
BIOLOGY
Dogs are highly variable in height and weight. The smallest known adult dog was a Yorkshire Terrier, that stood only 2.5 in. at
the shoulder, 3.7 in. in length along the head-and-body, and weighed only 4.0 oz. The largest known dog was an English Mastiff
which weighed 345 lbs and was 98 in. from snout to tail. The tallest dog is the Great Dane that stands 42.0 in. at the shoulder.
SENSES
Sight----Like most mammals, dogs are dichromats and have color vision equivalent to red-green color blindness in humans. The
dog's visual system has evolved to aid proficient hunting.
Hearing----The frequency range of dog hearing is approximately 40 Hz to 60,000 Hz, which means that dogs can detect sounds
far beyond the upper limit of human auditory spectrum. A dog can identify a sound's location much faster that an human can, as
well as hear sounds at four times the distance.
Smell----While the human brain is dominated by a large visual cortex, the dog brain is dominated by an olfactory cortex. The
olfactory bulb in dogs is roughly forty times bigger than the olfactory bulb in humans. Dogs can discriminate odors at
concentrations nearly 100 million times lower than humans can.
MORTALITY
The typical lifespan of dogs varies widely among breeds, but for the median longevity, the age at which half the dogs in a
population have died and half are still alive, ranges from 10 to 13 years.
The breed with the shortest lifespan is the Dogue de Bordeaux, with a median longevity of about 5.2 years, but several breeds,
including the Miniature Bull Terriers, Bloodhounds, and the Irish Wolfhounds are nearly as short-lived, with median longevities of 6
to 7 years.
The longest-lived breeds, including the Toy Poodle, Japanese Spitz, Border Terriers, and Tibetan Spaniels, have median longevities
of 14 to 15 years. The dog widely reported to be the longest-lived is "Bluey", who died in 1939 and was claimed to be 29.5
years old at the time of his death.

--forefoot

pastern--

--forearm

shoulder
\

muzzle---

stop
/

tail--

thigh---

hock--

carpus--

\
nose

lip--

ear--

cheek--

withers
/

back
/

loin
/

hip

/
brisket

--stifle

The Body of the Dog

BACK- the part of the body between the loin and withers.
BRISKET-the chest of the dog.
EAR- the fleshy, ofter triangular appendages on the head
associated with hearing.
FLEWS-the hanging part of the dog's upper lip.
FOREARM-the part of the foreleg between the elbow and
the pastern.
FOREFOOT-the front feet.
HINDFOOT-the back feet.
HIP- the joints at the uppermost part of the hindlegs.
HOCK-the bones that form the ankle/heel of the dog.

--flews

--hindfoot

LOIN-the part of the body located on both sides of the
backbone between the ribs and the hips.
MUZZLE-the front part of the jaws.
NOSE-the tip of the muzzle.
PASTERN-the part of the leg below the carpals (wrist) of the
front leg or below the hock of the hind leg.
RUFF-the long, thick hair that grows around the neck.
SHOULDER-the joint at the uppermost part of the forelegs.
STIFLE-the dog's knee, located on the hind leg above the ankle.
STOP-the indented part of the skull between the eyes.
TAIL-the hind-most part of the backbone, set on the rump.
THIGH-the upper part of the hind leg.
WITHERS-the top of the shoulders, just behind the neck.

/
ruff

Experts in calculating dog age tell us that the old
wisdom of 1 human year being equal to 7 dog years
isn't quite correct. They do the math according to
the following chart:

Dog Age
1
3
4
5
6
7
8
9
10
11
12
13
14
15
16

12
19
26
33
40
47
54
61
68
75
82
89
96
103
110

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