biology

Rolfodon

Rolfodon 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 Rolfodon rather than just read about it. In short: Rolfodon is an extinct genus of shark in the family Chlamydoselachidae. It is closely related to the extant frilled sharks in the genus Chlamydoselachus, which it can be differentiated from by tooth morphology.

Key takeaways

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

Reference excerpt

Rolfodon is an extinct genus of shark in the family Chlamydoselachidae. It is closely related to the extant frilled sharks in the genus Chlamydoselachus, which it can be differentiated from by tooth morphology. It is named after late Canadian paleontologist Rolf Ludvigsen. The earliest fossil teeth of Rolfodon are known from the Late Cretaceous (Turonian/Santonian boundary) of Japan, and it is one of two genera of Chlamydoselachidae along with Chlamydoselachus known to have survived the Cretaceous–Paleogene extinction event, although unlike Chlamydoselachus, Rolfodon went extinct by the Early Pliocene. Remains are known from worldwide, including Japan, Canada, Austria, New Zealand, Angola, Ecuador, and Antarctica. As with modern frilled sharks, Rolfodon appears to have been specialized to deep-water environments.

Species The following species are known:

R. bracheri (Pfeil, 1983) – Early Miocene (Aquitanian to Burdigalian) of Austria, Germany & Japan R. fiedleri (Pfeil, 1983) – Late Eocene (Bartonian) of Austria R. goliath (Antunes & Cappetta, 2002) – Late Cretaceous (Campanian) of Angola R. keyesi (Mannering & Hiller 2008) – Early Paleocene of New Zealand R. landinii (Carrillo-Briceño et al. 2014) – Middle Miocene (Langhian to Serravallian) of Ecuador R. ludvigseni Cappetta, Morrison & Adnet, 2019 – Campanian of British Columbia, Canada (Northumberland Formation) R. tatere (Consoli, 2008) – Late Cretaceous (Maastrichtian) to Early Paleocene of New Zealand and Antarctica R. thomsoni (Richter & Ward, 1990) – Maastrichtian of Antarctica The majority of these species were previously classified in Chlamydoselachus. One species, Chlamydoselachus baumgartneri, was moved to its own genus Proteothrinax in 2012. P. baumgartneri was later found to be conspecific with the previously described C. fiedleri, but fiedleri was found to belong to Rolfodon by Cappeta et al (2019). In addition to the genus as a whole, one individual species is also known to have survived the Cretaceous-Paleogene extinction event: R. tatere, which was first described from the Early Paleocene of New Zealand and was later also identified from the Late Cretaceous of Antarctica, extending the record of its existence by over 10 million years. R. bracheri from the Early Miocene was one of the most widespread species, with fossil teeth known from the European Paratethys and from Japan. The last records of Rolfodon are indeterminate teeth from the Early Pliocene of Japan. R. goliath, from the Late Campanian of Angola's southern Benguela Basin, could grow to very large sizes. It was described by Miguel Telles Antunes and Henri Cappetta in 2002 during the beginning stages of the PaleoAngola project. The holotype, MUS ANG 23, is rather large. This tooth is about 20mm high, and is characterised by straightened, upright cusps with smooth enameloid which lack ornamentation.

References

Illustrations

Worked examples

Example 1 — a first encounter with Rolfodon

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

In research: Rolfodon 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 Rolfodon 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: Rolfodon is common in secondary-school and first-year university syllabi. It links to neighbouring topics Campanian genus first appearances, Chlamydoselachidae, Fossil taxa described in 2019, so understanding it makes those chapters shorter.
In everyday life: Look for Rolfodon 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 Rolfodon in 20 minutes

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

Frequently asked questions

What is Rolfodon in simple terms?

Why does Rolfodon 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 Rolfodon?

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 Rolfodon.