science

Strophodus

Strophodus 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 Strophodus rather than just read about it. In short: Strophodus is an extinct genus of durophagous hybodont known from the Triassic to Cretaceous. It was formerly confused with Asteracanthus.

Key takeaways

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

Reference excerpt

Strophodus is an extinct genus of durophagous hybodont known from the Triassic to Cretaceous. It was formerly confused with Asteracanthus.

Taxonomy It has long been confused with Asteracanthus due to the fin spines of the latter being found associated with the teeth of Strophodus. However, both genera can now be reliably be distinguished base on the morphology of both the fin spines and teeth.

Description

Species of Strophodus had heavily rounded, durophagous crushing teeth, contrasting strongly with those of Asteracanthus, which are much more similar to those of Hybodus. Species of Strophodus have been estimated to reach up to 3 metres (9.8 ft) in length, making them some of the largest hybodonts. Like Asteracanthus, but unlike other hybodonts, the fin spines of Strophodus are covered in tubercles rather than being ribbed.

Ecology

Strophodus has been interpreted as a bottom-dwelling animal that fed on hard-shelled invertebrates, though isotopic evidence has suggested that it may have been pelagic. It may also have been euryhaline.

Species Species of Strophodus:

S. reticulatus (Agassiz, 1838) Middle-Late Jurassic (Bathonian–Tithonian) England, France, Germany, Hungary and Switzerland. A similar form S. cf. reticulatus is known from the Middle Triassic of Switzerland S. atlasensis (Stumpf et al., 2023) Middle Jurassic (Bajocian) Morocco S. smithwoodwardi (Peyer, 1946) Early Jurassic (Toarcian) Switzerland S. dunaii (Szabó & Főzy, 2020) Middle Jurassic (Aalenian) Hungary S. tenuis (Agassiz, 1838) Middle Jurassic (Aalenian-Bathonian) Germany, England S. longidens (Agassiz, 1838) Middle Jurassic (Bathonian) France S. magnus (Agassiz, 1838) Middle Jurassic (Bathonian) France, India, England S. indicus (Sharma & Singh, 2021) Middle Jurassic (Bathonian) India S. jaisalmerensis (Kumar et al., 2021) Middle Jurassic (Bathonian) India S. medius (Owen, 1869) Middle Jurassic (Bathonian-Callovian) India, France, England S. subreticulatus (Agassiz, 1838) Late Jurassic (Kimmeridgian) Switzerland S. timoluebkei (Carrillo-Briceño et al., 2025) Late Jurassic Switzerland S. udulfensis (Leuzinger et al., 2017) Late Jurassic (Kimmeridgian) Switzerland, ?England S. tridentinus (Zittel, 1870) Late Jurassic (Tithonian) Italy (possibly a nomen dubium) S. rebecae (Carrillo-Briceño & Cadena, 2022) Early Cretaceous (Valanginian-Hauterivian) Colombia Indeterminate remains of Strophodus possibly extend into the Albian stage of the Early Cretaceous. Claimed records of the genus from the Late Cretaceous are doubtful.

References

Illustrations

Worked examples

Example 1 — a first encounter with Strophodus

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

In research: Strophodus 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 Strophodus 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: Strophodus is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cretaceous Colombia, Cretaceous cartilaginous fish, Early Cretaceous fish of South America, so understanding it makes those chapters shorter.
In everyday life: Look for Strophodus 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Strophodus” →

Affiliate

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

How to study Strophodus in 20 minutes

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

Frequently asked questions

What is Strophodus in simple terms?

Strophodus is an extinct genus of durophagous hybodont known from the Triassic to Cretaceous. It was formerly confused with Asteracanthus.

Why does Strophodus 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 Strophodus?

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 Strophodus.