biology

Staurinidia

Staurinidia 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 Staurinidia rather than just read about it. In short: Staurinidia is a genus of Ediacaran soft-bodied organism from the deposits of the Ust' Pinega Formation. It is a monotypic genus, containing only the single species Staurinidia crucicula.

Key takeaways

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

Reference excerpt

Staurinidia is a genus of Ediacaran soft-bodied organism from the deposits of the Ust' Pinega Formation. It is a monotypic genus, containing only the single species Staurinidia crucicula. The genus was first described in 1985 by Russian palaeontologist Mikhail A. Fedonkin. S. crucicula's four-fold symmetry is present as a result of four canals radiating from the middle of a small cavity in the middle of the body. Other forms with four way symmetry, mainly medusoid forms, from the Ediacaran (Conomedusites, Persimedusites) comprise an essential chunk of the Ediacaran diversity of symmetry; their organisations are similar to, though smaller than, those of a modern-day scyphozoan cnidarian.

Description Staurinidia crucicula fossils are commonly preserved as a small discoidal form baring four radial canals emitting from the centre, in which a small cavity is present. The ends of the canals are often swollen when pointing towards the organisms periphery. In larger fossils, tentacles have been found present and preserved around the outside of the disc's margin, which itself is very thin and having no indication of an encircling ridge or canal. A recent study also found a much larger specimen, most likely an adult, with fully complete canals and tentacles, which showed that the canals bifurcate several times before reaching the outer margin of the body. The diameter of the body of Staurinidia ranges from 6–7 mm (0.2–0.3 in) in young specimens to 50 mm (2.0 in) in adult specimens, with the width of the canal being 1 mm (0.0 in) and the length of the marginal tentacles being 4–5 mm (0.2–0.2 in) in length. The canals give the animal a four-fold symmetry typical to that of other Ediacaran cnidarians. As such, Staurinidia is regarded as one of the simplest of all Ediacaran cnidarians that show four-way rotational axis.

Illustrations

Worked examples

Example 1 — a first encounter with Staurinidia

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

In research: Staurinidia 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 Staurinidia 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: Staurinidia is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cnidaria taxa, Ediacaran, Ediacaran first appearances, so understanding it makes those chapters shorter.
In everyday life: Look for Staurinidia 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 Staurinidia in 20 minutes

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

Frequently asked questions

What is Staurinidia in simple terms?

Staurinidia is a genus of Ediacaran soft-bodied organism from the deposits of the Ust' Pinega Formation. It is a monotypic genus, containing only the single species Staurinidia crucicula.

Why does Staurinidia 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 Staurinidia?

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 Staurinidia.