Differences From North American Beaver
Although the Eurasian beaver appears superficially similar to the North American beaver, there are several important differences between the two species.
Aside from being the larger of the two species, the Eurasian beaver has the following anatomical differences to North American beaver: it has a larger, less rounded head; a longer, narrower muzzle; a narrower, less oval-shaped tail; shorter shin bones, making it less capable of bipedal locomotion than the North American species. The Eurasian beaver also has longer nasal bones, with the widest point being at the end of the snout; in the case of the North American beaver, the widest point is at the middle of the snout. The Eurasian beaver has a triangular nasal opening, unlike those of the North American beavers, which are square. Furthermore, the foramen magnum is rounded in the Eurasian beaver, but triangular in the North American beaver. The anal glands of the Eurasian beaver are larger, and thin-walled, with a large internal volume, relative to that of the North American beaver. The guard hairs of the Eurasian beaver have longer hollow medullas at their tips. There is also a difference in fur colour: overall, 66% of Eurasian beavers have beige or pale brown fur, 20% have reddish brown, nearly 8% are brown, and only 4% have blackish coats; in North American beavers, 50% have pale brown fur, 25% are reddish brown, 20% are brown, and 6% are blackish.
The two species are not genetically compatible. The North American beaver has 40 chromosomes, while the Eurasian beaver has 48. After more than 27 attempts, made in Russia, to hybridize the two species, the result was one stillborn kit from bred from the pairing of a male North American beaver and a female Eurasian beaver. The aforementioned factor makes interspecific breeding unlikely in areas where the two species' ranges overlap.
Read more about this topic: Eurasian Beaver
Famous quotes containing the words differences, north, american and/or beaver:
“I don’t know what immutable differences exist between men and women apart from differences in their genitals; perhaps there are some other unchangeable differences; probably there are a number of irrelevant differences. But it is clear that until social expectations for men and women are equal, until we provide equal respect for both men and women, our answers to this question will simply reflect our prejudices.”
—Naomi Weisstein (b. 1939)
“Ah, how shall you know the dreary sorrow at the North Gate,
With Li Po’s name forgotten,
And we guardsmen fed to the tigers.”
—Li Po (701–762)
“Miss U.S.A. is in the same graveyard that [Amanda Jones] the twelve-year-old is. Where the sixteen-year-old is. All the past selves. There comes a time when you have to bury those selves because you’ve grown into another one.”
—Amanda Theodosia Jones, U.S. beauty contest winner, Miss U.S.A., 1973. As quoted under the pseudonym “Emma Wright” in American Dreams, Prologue, by Studs Terkel (1980)
“This ferry was as busy as a beaver dam, and all the world seemed anxious to get across the Merrimack River at this particular point, waiting to get set over,—children with their two cents done up in paper, jail-birds broke lose and constable with warrant, travelers from distant lands to distant lands, men and women to whom the Merrimack River was a bar.”
—Henry David Thoreau (1817–1862)