Ungual tuft

Key takeaways

Ungual tuft belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Ungual tuft to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Ungual tuft from memory before moving on to harder problems.

Reference excerpt

In mammals, ungual tufts are tufts of hairs at the base of claws of the forefeet and hindfeet. Their presence has been used as a character in cladistic studies of the Cricetidae, a large family of rodents.

Rice rats Members of the tribe Oryzomyini ("rice rats"), in the Cricetidae subfamily Sigmodontinae, normally have ungual tufts, but they may be reduced or absent in semiaquatic species (i.e. those adapted to life in the water). Lundomys molitor, Nectomys apicalis, the marsh rice rat (Oryzomys palustris), and species of Holochilus lack ungual tufts on their forefeet. On the hindfeet, most species have well-developed ungual tufts only on the second to fifth toes, but Sooretamys angouya and Eremoryzomys polius also have thick tufts on the first toe. Pseudoryzomys simplex, Mindomys hammondi, Nectomys squamipes, Sigmodontomys alfari, Oryzomys couesi, the marsh rice rat, and species of Melanomys have sparse ungual tufts only, and Lundomys molitor, Nectomys apicalis, Sigmodontomys aphrastus, and species of Holochilus have very reduced tufts or lack them entirely.

Other examples Among other South American cricetids, Abrothrix lanosus has white ungual tufts that are shorter than the claws. Akodon paranaensis has long ungual tufts. Calomys cerqueirai has silvery tufts on the second through fifth digits of the forefeet and all digits of the hindfeet. Abrawayaomys has long, dense ungual tufts. The Tylomyinae are characterized by the presence of ungual tufts on their hindfeet. White ungual tufts are also present in the Philippine murine genus Batomys. B. hamiguitan and B. russatus have short tips, not extending to the tips of the claws, but those of B. granti and B. salomonseni have tufts longer than the claws. The Malagasy Monticolomys has long ungual tufts, extending beyond the claws, whereas the related Macrotarsomys has shorter tufts. The Brazilian spiny rat Phyllomys sulinus has long, light gray ungual tufts. The tenrec Microgale jobihely has long, dark brown ungual tufts. The opossum Monodelphis handleyi has short ungual tufts.

References

Bibliography Balete, D.S., Heaney, L.R., Rickart, E.A., Quidlat, R.S. and Ibanez, J.C. 2008. A new species of Batomys (Mammalia: Muridae) from eastern Mindanao Island, Philippines. Proceedings of the Biological Society of Washington 121(4):411–428. Bonvicino, C.R., de Oliveira, J.A. and Gentile, R. 2010. A new species of Calomys (Rodentia: Sigmodontinae) from southeastern Brazil. Zootaxa 2336:19–35. Carleton, M.D. and Goodman, S.M. 1996. Systematic studies of Madagascar's endemic rodents (Muroidea: Nesomyinae): a new genus and species from the central highlands. Fieldiana Zoology 85:231–256. Christoff, A.U., Fagundes, V., Sbalqueiro, I.J., Mattevi, M.S. and Yonenaga-Yassuda, Y. 2000. Description of a new species of Akodon (Rodentia: Sigmodontinae) from southern Brazil. Journal of Mammalogy 81(3):838–851. Feijoo, M., D'Elía, G., Pardiñas, U.F.J. and Lessa, E.P. 2010. Systematics of the southern Patagonian-Fueguian endemic Abrothrix lanosus (Rodentia: Sigmodontinae): Phylogenetic position, karyotypic and morphological data (subscription required). Mammalian Biology 75:122–137. Goodman, S.M., Raxworthy, C.J., Maminirina, C.P. and Olson, L.E. 2006. A new species of shrew tenrec (Microgale jobihely) from northern Madagascar. Journal of Zoology 270:384–398. Leite, Y.L.R., Christoff, A.U. and Fagundes, V. 2008. A new species of Atlantic Forest tree rat, genus Phyllomys (Rodentia, Echimyidae) from southern Brazil. Journal of Mammalogy 89:845–851. Musser, G.G. and Carleton, M.D. 2005. Superfamily Muroidea. Pp. 894–1531 in Wilson, D.E. and Reeder, D.M. (eds.). Mammal Species of the World: a taxonomic and geographic reference. 3rd ed. Baltimore: The Johns Hopkins University Press, 2 vols., 2142 pp. ISBN 978-0-8018-8221-0 Pardiñas, U.F.J., Teta, P. and D'Elía, G. 2009. Taxonomy and distribution of Abrawayaomys (Rodentia: Cricetidae), an Atlantic Forest endemic with the description of a new species. Zootaxa 2128:39–60. Solari, S. 2007. New species of Monodelphis (Didelphimorphia: Didelphidae) from Peru, with notes on M. adusta (Thomas, 1897). Journal of Mammalogy 88:319–329. Weksler, M. 2006. Phylogenetic relationships of oryzomyine rodents (Muroidea: Sigmodontinae): separate and combined analyses of morphological and molecular data. Bulletin of the American Museum of Natural History 296:1–149.

Worked examples

Example 1 — a first encounter with Ungual tuft

Start with the simplest possible case. Write down what Ungual tuft claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Ungual tuft before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Ungual tuft ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Ungual tuft

In research: Ungual tuft appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Ungual tuft in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Ungual tuft is common in secondary-school and first-year university syllabi. It links to neighbouring topics Mammal anatomy, so understanding it makes those chapters shorter.
In everyday life: Look for Ungual tuft outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Ungual tuft in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Ungual tuft means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Ungual tuft out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Ungual tuft in simple terms?

In mammals, ungual tufts are tufts of hairs at the base of claws of the forefeet and hindfeet. Their presence has been used as a character in cladistic studies of the Cricetidae, a large family of rodents.

Why does Ungual tuft matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Ungual tuft?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Ungual tuft.