biology

Ohaniella

Ohaniella 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 Ohaniella rather than just read about it. In short: Ohaniella (IPA: [ɔː.hɑ.ni.ɛl.la]) (named after Tamiko Ohana Japanese: 大花民子) is a monotypic whole-plant genus of williamsoniacean bennettitalean from the Tochikubo Formation of Fukushima, northeast Japan. The type species is Ohaniella ptilofolia, known from various whole-plant specimens comprising leaf-bearing branches and disarticulated leaves of the Ptilophyllum jurassicum-type, a mature or maturing seed cone of t…

Key takeaways

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

Reference excerpt

Ohaniella (IPA: [ɔː.hɑ.ni.ɛl.la]) (named after Tamiko Ohana Japanese: 大花民子) is a monotypic whole-plant genus of williamsoniacean bennettitalean from the Tochikubo Formation of Fukushima, northeast Japan. The type species is Ohaniella ptilofolia, known from various whole-plant specimens comprising leaf-bearing branches and disarticulated leaves of the Ptilophyllum jurassicum-type, a mature or maturing seed cone of the Bennetticarpus-type, and potential male reproductive organs of the Weltrichia-type.

Etymology The generic name (Ohaniella IPA: [ɔː.hɑ.ni.ɛl.la]) is after Tamiko Ohana (IPA: [tamiko ɔːhɑnɑ]) (Japanese: 大花民子 IPA: [ɔː.hɑ.nɑ ta.mi.ko]) using the Latin suffix -ella (a commonly used suffix in binomial nomenclature named after a person) "in honour of her excellent contributions to Japanese palaeobotany". The specific name (ptilofolia (IPA: [ptí.lo.ˈfɔː.li.a]) is from the Ancient Greek word πτίλον (ptĭ́lon (IPA: [ptí.lon])) (which translates to feather) and the Latin folium (IPA: [ˈfɔː.li.um])) (which translates to leaf) in reference to the Ptilophyllum jurassicum-type foliage of the plant.

Description

Pott and Takimoto (2025) investigated six specimens, two of which they designated the holotype (MM-000940) and epitype (MM-000941). Both specimens consist of a branched axis with attached leaves. The holotype preserves a Bennetticarpus-type mature or maturing seed cone at the terminal end of the axis, while MM-000951 and MM-000949 preserve possible microsporangiate organs (pollen cones) of the Weltrichia-type besides the associated Ptilophyllum jurassicum-type foliage. This led the authors to refrain from making a confirmed referral but still mention the possibility that these could be the microsporangiate organs of the plant.

'Penultimate pinnae' ?Nipponoptilophyllum bipinnatum In their description of Ohaniella, Pott and Takimoto also examined more than 50 additional specimens of disarticulated leaves. In the process, they re-examined the original material of Nipponoptilophyllum bipinnatum and found that not only was the assumed bipinnate nature of the leaves not conclusive based on the available material, but also that 49 specimens of detached leaves (referred to as 'penultimate pinnae' in a previous paper) may be conspecific with P. jurassicum if the bipinnate nature of the leaves is not reflective of the actual anatomy.

Ptilophyllum oshikaense In the examination of disarticulated leaves, the authors concluded that the differences between P. oshikaense and P. jurassicum are "so marginal that they better range within the limits of intraspecific variation than discriminate between leaf taxa", making "P. oshikaense" a junior synonym of P. jurassicum.

Palaeobiology Ohaniella preserves similar growth structures to other bennettitaleans, including divaricately branched growth with the reproductive organs growing on the terminal end of the main axis, later inducing lateral branching during the next growth period (the period probably being seasonally or annually). Pott and Takimoto further interpreted Ohaniella as having a similar overall architecture to the whole-plant williamsoniacean Kimuriella, specifically a "low-growing shrub-like [plant] probably up to 1–2 m tall... [with] divaricately branched axes [that] probably formed tangled shrub thickets with interlaced axes". They noted that the two plants still warrant different genera as "the foliage of the two plants [is] placed in two different but sound genera" with Kimuriella possessing Zamites-type foliage and Ohaniella possessing Ptilophyllum-type foliage respectively.

Palaeoecology The Tochikubo Formation, from which Ohaniella is known, has been interpreted as a mostly non-marine fluvial to near-shore and low-energy lake deposit, with the facies of the formation changing in ascending order from fluvial to lake association, flood plain, alluvial fan into a delta-front coastal environment in its uppermost part. The authors that described the plant state that "it is reasonable to assume that O. ptilofolia...also extended its habitat into brackish to tidal mudflat areas or tidelands similar to those found in modern mangroves or saltmarshes," growing in "brackish to tidal mudflat areas or delta settings that were regularly flooded such as in mangroves or tideland habitats."

References

Illustrations

Worked examples

Example 1 — a first encounter with Ohaniella

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

In research: Ohaniella 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 Ohaniella 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: Ohaniella is common in secondary-school and first-year university syllabi. It links to neighbouring topics Bennettitales, Fossil taxa described in 2025, Jurassic plants, so understanding it makes those chapters shorter.
In everyday life: Look for Ohaniella 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 Ohaniella in 20 minutes

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

Frequently asked questions

What is Ohaniella in simple terms?

Why does Ohaniella 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 Ohaniella?

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 Ohaniella.