Lesson plan
Cryptotis
The genus Cryptotis is a group of relatively small shrews with short ears, which are usually not visible, and short tails, commonly called small-eared shrews. They have 30 teeth and are members of the red-toothed shrew subfamily. Since 1992, Neal Woodman (in cooperation with Robert Timm) at the United States National Museum has been in the process of revising the genus. To date, this has resulted in an increase in the number of species from 12 to 30. Members of the genus are found mainly in Central America; the North American least shrew, C. parva, is the only species found north of Mexico. The genus occurs as far south as northern Peru and as far east as western Venezuela in South America. It is the only soricomorph genus found south of Guatemala. The limited diversity and restricted northern distribution of shrews in South America implies that the group entered the continent relatively recently from Central America, where they are more diverse, presumably as part of the Great American Interchange. However, shrews have no fossil record in South America that would allow their arrival to be dated.
Article summary
The genus Cryptotis is a group of relatively small shrews with short ears, which are usually not visible, and short tails, commonly called small-eared shrews. They have 30 teeth and are members of the red-toothed shrew subfamily. Since 1992, Neal Woodman (in cooperation with Robert Timm) at the United States National Museum has been in the process of revising the genus. To date, this has resulted in an increase in the number of species from 12 to 30. Members of the genus are found mainly in Central America; the North American least shrew, C. parva, is the only species found north of Mexico. The genus occurs as far south as northern Peru and as far east as western Venezuela in South America. It is the only soricomorph genus found south of Guatemala. The limited diversity and restricted northern distribution of shrews in South America implies that the group entered the continent relatively recently from Central America, where they are more diverse, presumably as part of the Great American Interchange. However, shrews have no fossil record in South America that would allow their arrival to be dated.
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Discussion questions
- Summarise the article in your own words. Which single claim would you verify first, and why?
- Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
- If two sources disagreed about one of these facts, what would you need in order to trust one over the other?
Bibliography
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Key claims and bibliography are generated from the same tracked claims and sources as the article page.