science

Perimys

Perimys is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Perimys rather than just read about it. In short: Perimys is an extinct genus of neoepiblemid rodent that lived from the Early to Late Miocene in what is now South America. Fossils have been found in the Cerro Bandera, Cerro Boleadoras, Ituzaingó, Santa Cruz, and Sarmiento Formations of Argentina, and the Galera, Santa Cruz, and Río Frías Formations of Chile.

Key takeaways

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

Reference excerpt

Perimys is an extinct genus of neoepiblemid rodent that lived from the Early to Late Miocene in what is now South America. Fossils have been found in the Cerro Bandera, Cerro Boleadoras, Ituzaingó, Santa Cruz, and Sarmiento Formations of Argentina, and the Galera, Santa Cruz, and Río Frías Formations of Chile.

Description Perimys was a medium to large-sized rodent. Perimys can be distinguished from other caviomorphs in having euhypsodont and bilophodont cheek teeth, with the hypoflexus/id being conspicuously broader and filled with more cementum than in Prolagostomus and Pliolagostomus. As a result, the teeth of Perimys have a U-shape occlusal outline. The malleoincudal complex of Perimys indicates its head was elongated, but not to the same extent as in chinchillines. As in chinchillids, however, the incudal long process of Perimys is more prolonged by a slight amount than the short process.

Taxonomy Perimys was first described by Florentino Ameghino in 1887 based on remains found in the Santa Cruz Formation of Argentina, with the proposed type species being Perimys erutus. Several other species have been described as pertaining to this genus. Ameghino originally assigned it to the obsolete family Eryomyidae, however, many later authors have assigned it to the Neoepiblemidae family. The following cladogram of the Caviomorpha is based on Busker et al. 2020, showing the position of Perimys.

Palaeobiology Functional analysis of its scapula, humerus, ulna, and radius suggests that Perimys would have been well adapted for fossoriality.

References

Illustrations

Worked examples

Example 1 — a first encounter with Perimys

Start with the simplest possible case. Write down what Perimys claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 Perimys 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 Perimys 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 Perimys

In research: Perimys appears in science 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 Perimys 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: Perimys is common in secondary-school and first-year university syllabi. It links to neighbouring topics Austral or Magallanes Basin, Cerro Bandera Formation, Chasicoan, so understanding it makes those chapters shorter.
In everyday life: Look for Perimys 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.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Perimys in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Perimys 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 Perimys out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Perimys in simple terms?

Why does Perimys matter?

Because it connects several science 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 Perimys?

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 Perimys.