Passage 2 : Paleontology
Three Mammoth Species
The two modern elephant species maintain the exclusive status of being the largest land mammals on the planet. In the past, however, they had to share this distinction. Their closest prehistoric relatives were the mammoths, which lived during the period between approximately 4,000,000 and 5,0 years ago, and most of these species were as large as, if not larger than, the elephants that survive today.
Paleontologists have pieced together an accurate understanding of the physical structures and behavioral patterns of mammoths from fossils and other specimens that have been collected around the globe. Some of the most significant finds have involved complete mammoth carcasses preserved in the glaciers and permafrost of Siberia and Alaska, which are particularly useful to scientists because they provide samples of tissue, hair, and even undigested food from these creatures that perished so long ago. Unearthed skeletal remains are also extremely valuable, as they can explain some of the growth patterns and evolutionary transformations of the mammoth. The most frequently encountered remnants of these ancient mammals are fossilized teeth, which have been found in numerous sites in North America, Europe, Asia, and Africa.
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The many different mammoth species varied greatly in size, anatomy, and habitat, yet they all possessed some of the same general traits. They were vegetarians, equipped with large, flat molars to grind and chew plant material, and consumed enormous amounts of food during a typical day. Their upper incisors developed into two great tusks, and their nose and upper lip joined to create the familiar elephant-like trunk. In addition to these obvious similarities, however, each type of mammoth displayed features that set it apart from its relatives.
The Columbian mammoth (Mammuthus columbi) was the largest of all the mammoths. It stood around fourteen feet tall at the shoulder and could weigh more than ten tons—almost twice as heavy as any other species. The largest pair of tusks ever uncovered, which were sixteen feet in length, belonged to a Columbian mammoth. It made its home in the warmer regions of North America, reaching as far south as Central America. Fossil evidence shows that this species lived between 100,000 and 9,000 years ago, making it one of the last large mammoths to become extinct.
Mammuthus primigenius, commonly known as the woolly mammoth, is perhaps the most easily recognizable species. It was also the most successful, despite inhabiting, unlike many other mammoths, the far northern expanses of the globe. [A] First appearing 250,0 years ago, by about 100,000 years ago it occupied a range along the entire northern rim, from the British Isles east through Siberia, over the Bering land bridge, and into northern Canada. [B] To withstand the frigid climate, the woolly mammoth developed long, dense coats of hair and fur, giving it a truly extraordinary appearance. [C] With a height of ten feet and weighing about five tons, it was much smaller than the Columbian mammoth, and its tusks were also slightly shorter, reaching a maximum length of fourteen feet. [D] Similar to those of other mammoth species, though, they curved much more than the tusks of modem elephants do. Paleontologists estimate that the woolly mammoth disappeared around 10,000 years ago.
=> Though it may be hard to believe, not all mammoth species were large. In fact there are two well-documented cases of pygmy mammoth populations. One of these was simply a smaller version of the woolly mammoth that inhabited Wrangel Island off the coast of Siberia. The other type of pygmy mammoth is actually considered a unique species (Mammuthus exilis) and lived on the Channel Islands just west of California. This species most likely evolved from Columbian mammoths that wandered over to the islands during a period of reduced sea levels between 20,0 and 30,000 years ago. Once there, the limited space and resources available on the islands forced them to evolve smaller bodies in order to adapt. The Channel Islands pygmies had an average height of just six feet and weighed only a ton or two. Interestingly, though, these miniature mammoths lasted longer than any other species, with the extinction of the Wrangel Island pygmies occurring only about 4,000 years ago.
13. The word exclusive in the passage is closest in meaning to
14. According to paragraph 1, what is true about the relationship between mammoths and elephants?
(A) Elephants evolved after mammoths became extinct.
(B) They share no common ancestors.
(C) Early elephants were larger than the mammoths.
(D) They coexisted in prehistoric times.
Paragraph 1 is marked with an arrow !■♦].
15 . Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.
(A) The sites of the some of the most exciting mammoth finds have been located in the frozen regions of the world.
(B) Under certain conditions, the food a mammoth was eating at the time of its death was preserved along with its body.
(C) Scientists can gather more information from a frozen mammoth carcass than they can from other types of remains.
(D) Important biological and dietary information has been gained from discoveries of ancient, naturally preserved mammoth bodies trapped in ice.
16. What can be inferred from the discussion of fossilized teeth in paragraph 2?
(A) Many mammoth species originated in • North America.
(B) Mammoths were present in multiple parts of the world.
(C) Fossils are most commonly found in far northern areas.
(D) Australia contains the fewest mammoth skeletal remains.
Paragraph 2 is marked with an arrow (■♦].
17. The word remnants in the passage is closest in meaning to
18. The word traits in the passage is closest in meaning to
19. Why does the author mention the elephant- like trunk in paragraph 3?
(A) To explain why all mammoths were vegetarians
(B) To argue that mammoths were similar to the modern elephants
(C) To name an identifying feature possessed by all mammoths
(D) To describe a method used to distinguish different mammoth species
Paragraph 3 is marked with an arrow [■*].
20. From paragraph 4, it can be inferred that tusk length in mammoths was
(A) generally proportionate to body size
(B) mostly related to the animals’ diets
(C) dependent on habitat and climate
(D) determined by when the species lived
Paragraph 4 is marked with an arrow [■♦i.
21. The word withstand in the passage is closest in meaning to
22. According to paragraph 5, the woolly mammoth differed from other mammoths in all of the following EXCEPT
(A) hair growth
(B) type of habitat
(C) tusk shape
(D) extent of range
Paragraph 5 is marked with an arrow M.
23. According to paragraph 6, the Wrangel Island pygmies
(A) have not been designated a separate species
(B) appeared earlier than the Channel Islands pygmies
(C) are not considered to be mammoths
(D) were the descendants of the Channel Islands pygmies
Paragraph 6 is marked with an arrow i*^I.
24. The word them in the passage refers to
(A) Columbian mammoths
(B) sea levels
(D) miniature mammoths
25. Look at the four squares  that indicate where the following sentence could be added to the passage.
It also maintained a thick layer of fat just beneath the outer skin that served as insulation from the cold.
Where would the sentence best fit?
Click on a square B to add the sentence to the passage.
26. Directions: Complete the table by matching the phrases below.
Select the appropriate phrases from the answer choices and match them to the species of mammoth to which they relate. TWO of the answer choices will NOT be used. This question is worth 4 points.
Drag your answer choices to the spaces where they belong. To remove an answer choice, click on it To review the passage, click View Text
(A) Was probably the largest land mammal of its time
(B) Is more likely to have been preserved in glaciers
(C) Lost its trunk through a gradual evolutionary process
(D) Became extinct most recently
(E) Existed simultaneously on multiple continents
(F) Evolved in isolated habitats
(G) Had unusually straight tusks
(H) Appeared first around 100,000 years ago
(I) Is known to have lived in a tropical environment