biology

Lonchodomas

Lonchodomas 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 Lonchodomas rather than just read about it. In short: Lonchodomas is a genus of trilobites, that lived during the Ordovician. It was eyeless, like all raphiophorids, and had a long straight sword-like frontal spine, that gradually transforms into the relatively long glabella.

Key takeaways

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

Reference excerpt

Lonchodomas is a genus of trilobites, that lived during the Ordovician. It was eyeless, like all raphiophorids, and had a long straight sword-like frontal spine, that gradually transforms into the relatively long glabella. Both the glabellar spine and the backward directed genal spines are subquadrate in section. Lonchodomas has five thorax segments and the pleural area of the pygidium has two narrow furrows. Lonchodomas occurred in what are today Argentina, Canada (Newfoundland), Estonia, Latvia, Norway, Sweden, the Russian Federation (Leningrad Oblast) and the United States (Oklahoma, Virginia).

Distribution

L. carinatus is found in the Upper Ordovician of the United States (Lower Member and Botetourt limestone Member, of the Edinburgh Formation, Shenandoah County, Virginia, 39.0° N, 78.4° W Blackriveran 460.9 - 449.5 Ma) L. clavulus is present in the Middle Ordovician of Newfoundland, Canada (Histiodella kristinae conodont zone, Table Cove Formation; Table Point, "Middle Table Head" and Table Cove). L. mcgeheei is present in the Upper Ordovician of Oklahoma, United States (Bromide Formation, Sandbian). L. retrolatus was collected from the Ordovician of Nevada (Eureka Quartzite, sandy limestone, 60–90 ft above base, Ranger Mountains, Nevada Test Site)) L. rostratus is known from the Upper Ordovician of Estonia (Narva open pit, and Lasnamägi, Kukruse Stage, Sandbian) and Latvia (Remte 3 borehole, and Adze 6 borehole, Kukruse Stage, Sandbian). L. suriensis was excavated from the Middle Ordovician of Argentina (Portillo del Cajón, Cerro Morado; Cerro Suri; Puesto El Despacho; Las Pircas; all La Rioja) L. volborthi occurs in the Lower Ordovician of the Russian Federation (Volkhovian level, Syas River, Putilovo and Babino quarries, St.Petersburg region). It was originally described as Ampyx volborthi but assigned to Lonchodomas in 1952 by Steinar Skjeseth.

Description Like all raphiophorids, Lonchodomas is eyeless. The headshield (or cephalon) and tailshield (or pygidium) are subtriangular in outline. Lonchodomas looks a lot like Ampyx but the glabella is diamond-shaped in outline, and it has a ridge along the midline (it is carinate). The glabella gradually transforms into the spine, which makes it difficult to determine where the spine begins. The long median glabellar spine is subquadrate in section and is directed horizontally forward, from the frontal tip of the glabella. The glabella has 2 pairs of muscle scars. The genal spines are also subquadrate in section. The thorax has 5 segments. The pleural regions of pygidium have 2 pairs of narrow pleural furrows.

References

Illustrations

Worked examples

Example 1 — a first encounter with Lonchodomas

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

In research: Lonchodomas 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 Lonchodomas 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: Lonchodomas is common in secondary-school and first-year university syllabi. It links to neighbouring topics Asaphida genera, Bromide Formation, Fossils of Argentina, so understanding it makes those chapters shorter.
In everyday life: Look for Lonchodomas 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.

Affiliate

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

How to study Lonchodomas in 20 minutes

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

Frequently asked questions

What is Lonchodomas in simple terms?

Why does Lonchodomas 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 Lonchodomas?

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 Lonchodomas.