biology

Paraorthacodus

Paraorthacodus 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 Paraorthacodus rather than just read about it. In short: Paraorthacodus is an extinct genus of shark. It a member of the family Paraorthacodontidae (though it was formerly regarded as a member of the family Palaeospinacidae), which is either placed in Hexanchiformes or in Synechodontiformes.

Key takeaways

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

Reference excerpt

Paraorthacodus is an extinct genus of shark. It a member of the family Paraorthacodontidae (though it was formerly regarded as a member of the family Palaeospinacidae), which is either placed in Hexanchiformes or in Synechodontiformes. It is known from over a dozen named species spanning from the Early Jurassic to the Paleocene, or possibly Eocene. Almost all members of the genus are exclusively known from isolated teeth, with the exception of P. jurensis from the Late Jurassic-Early Cretaceous of Europe, which is known from full body fossils from the Late Jurassic of Germany, which suggest that juveniles had a robust body with a round head, while adults had large body sizes with a fusiform profile. There was only a single dorsal fin towards the back of the body without a fin spine. The dentition had teeth with a single large central cusp along with shorter lateral cusplets, which were designed for clutching. The teeth are distinguished from those of Synechodus by the lateral cusplets decreasing in size linearly away from the central cusp rather than exponentially as in Synechodus.

Taxonomy After

Paraorthacodus andersoni (Case, 1978) Late Cretaceous (Santonian and Campanian) Paraorthacodus antarcticus Klug et al., 2008 Late Cretaceous (Campanian) Paraorthacodus clarkii (Eastman, 1901) Paleocene (Thanetian) Paraorthacodus conicus (Davis, 1890) Late Cretaceous (Coniacian to Campanian) Paraorthacodus eocaenus (Leriche, 1902) Paleogene (Thanetian to Ypresian according to, exclusively Thanetian according to, considered a synonym of P. clarkii by) Paraorthacodus jurensis (Schweizer, 1964) Late Jurassic (Kimmeridgian) Paraorthacodus nerviensis (Leriche, 1929) uppermost Cretaceous Paraorthacodus patagonicus (Ameghino, 1893) Late Cretaceous (Coniacian) Paraorthacodus recurvus (Trautschold, 1877) Cretaceous (Albian-uppermost Cretaceous) Paraorthacodus sulcatus (Davis, 1888) Late Cretaceous (Campanian) Paraorthacodus validus (Chapman, 1918) from the Cretaceous Paraorthacodus turgaicus Glickman, 1964, Paleocene (Thanetian) Paraorthacodus helveticus (De Beaumont 1960) Early Jurassic (Sinemurian) Paraorthacodus arduennae Delsate, 2001) Early Jurassic (Pliensbachian) Paraorthacodus kruckowi (Thies 1983) Middle Jurassic (Aalenian)

References

Illustrations

Worked examples

Example 1 — a first encounter with Paraorthacodus

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

In research: Paraorthacodus 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 Paraorthacodus 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: Paraorthacodus is common in secondary-school and first-year university syllabi. It links to neighbouring topics Early Jurassic cartilaginous fish, Elasmobranchii, Fossil taxa described in 1957, so understanding it makes those chapters shorter.
In everyday life: Look for Paraorthacodus 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 Paraorthacodus in 20 minutes

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

Frequently asked questions

What is Paraorthacodus in simple terms?

Why does Paraorthacodus 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 Paraorthacodus?

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 Paraorthacodus.