biology

Hesperocyon

Hesperocyon is a biology 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 Hesperocyon rather than just read about it. In short: Hesperocyon is an extinct genus of canids belonging to the subfamily Hesperocyoninae of the canid family that was endemic to North America, ranging from southern Canada to Colorado. It appeared during the Uintan age, –Bridgerian age (NALMA) of the Mid-Eocene– 42.5 Ma to 31.0 Ma.

Key takeaways

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

Reference excerpt

Hesperocyon is an extinct genus of canids belonging to the subfamily Hesperocyoninae of the canid family that was endemic to North America, ranging from southern Canada to Colorado. It appeared during the Uintan age, –Bridgerian age (NALMA) of the Mid-Eocene– 42.5 Ma to 31.0 Ma. (AEO). Hesperocyon existed for approximately 11.5 million years.

Taxonomy

Hesperocyon was assigned to Borophagini by Wang et al. in 1999 and was the earliest of the canids to evolve after the Caniformia-Feliformia split some 42 million years ago. Fossil evidence dates Hesperocyon gregarius to at least 37 mya, but the oldest Hesperocyon has been dated at 39.74 mya from the Duchesnean North American land mammal age. The Canidae subfamily Hesperocyoninae probably arose out of Hesperocyon to become the first of the three great dogs groups: Hesperocyoninae (~40–30 Ma), Borophaginae (~36–2 Ma), and the Caninae lineage that led to the present-day canids (including grey wolves, foxes, coyotes, jackals and dogs). At least 28 known species of Hesperocyoninae evolved out of Hesperocyon, including those in the following five genera: Ectopocynus (32–19 mya), Osbornodon (32–18 mya), Paraenhydrocyon (20–25 mya), Mesocyon (31–15 mya) and Enhydrocyon (31–15 mya).

Evolution This genus of primitive canids is the ancestor of all later canids.

Morphology

This early, 80-centimeter-long (2 ft 7 in) canine looked more like a civet or a small raccoon. Its body and tail were long and flexible, while its limbs were weak and short. Still, the build of its ossicles and distribution of its teeth showed it was a canid. It may have been an omnivore—unlike the hypercarnivorous Borophaginae that later split from this canid lineage. Unlike modern canids, Hesperocyon had five fingers and toes and a dew claw deeply set enough to suggest tree climbing capabilities.

Fossil record The oldest fossil evidence was recovered from Saskatchewan dating from 42.5 mya to 31.0 Ma. The youngest fossil was recovered from the Dog Jaw Butte site, Goshen County, Wyoming dating to the Arikareean age (NALMA) of the Oligocene and Miocene 42.5 mya—31.0 Ma. (AEO).

Palaeobiology

Palaeopathology A number of individuals of Hesperocyon sp. have been found with evidence of hereditary osteochondroma, which manifested in the individuals as mushroom-like overgrowths of bone in the medial aspect of the distal half of their radii.

References

Illustrations

Worked examples

Example 1 — a first encounter with Hesperocyon

Start with the simplest possible case. Write down what Hesperocyon 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 Hesperocyon 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 Hesperocyon 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 Hesperocyon

In research: Hesperocyon 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 Hesperocyon 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: Hesperocyon is common in secondary-school and first-year university syllabi. It links to neighbouring topics Eocene carnivorans, Fossil taxa described in 1890, Hesperocyonines, so understanding it makes those chapters shorter.
In everyday life: Look for Hesperocyon 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.

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How to study Hesperocyon in 20 minutes

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

Frequently asked questions

What is Hesperocyon in simple terms?

Why does Hesperocyon 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 Hesperocyon?

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 Hesperocyon.