biology

Gryposuchinae

Gryposuchinae 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 Gryposuchinae rather than just read about it. In short: Gryposuchinae is an extinct subfamily of gavialid crocodylians. Gryposuchines lived mainly in the Miocene of South America.

Key takeaways

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

Reference excerpt

Gryposuchinae is an extinct subfamily of gavialid crocodylians. Gryposuchines lived mainly in the Miocene of South America. However, "Ikanogavialis" papuensis may have survived more recently, into the Late Pleistocene/Holocene. Most were long-snouted coastal forms. The group was named in 2007 and includes genera such as Gryposuchus and Aktiogavialis, although a 2018 study indicates that the group might be paraphyletic and rather an evolutionary grade towards the gharial.

Description

Gryposuchines had long, narrow snouts and most had protruding eye sockets. One distinguishing feature of the group is the lack of a large exposure of the prootic bone around the trigeminal foramen, a hole in the side of the braincase wall. Many Gryposuchines reached exceptionally large sizes, and are among the largest crocodilians ever described, with general like Gryposuchus containing individuals estimated to reach 10 meters.

Classification Gryposuchinae was named in 2007 as a subfamily of closely related gavialid crocodilians. It was cladistically defined as a stem-based taxon including Gryposuchus jessei and all crocodilians more closely related to it than to Gavialis gangeticus (the gharial) or Tomistoma schlegelii (the False gharial). The tomistomines (including the living false gharial) were long thought to be classified as crocodiles and not closely related to gavialoids. However, recent molecular studies using DNA sequencing have consistently indicated that the false gharial (Tomistoma) (and by inference other related extinct forms in Tomistominae) actually belong to Gavialoidea (and Gavialidae). A phylogenetic analysis conducted in the 2007 study found Gryposuchinae to include the genera Aktiogavialis, Gryposuchus, Ikanogavialis, Piscogavialis, and Siquisiquesuchus. The below cladogram is from the 2007 analysis showing the phylogenetic relationships of gryposuchines among gavialoids. Hesperogavialis was excluded due to a lack of skull material, and Dadagavialis due to its 2018 discovery.

Alternatively, phylogenetic studies recovering the tomistomines (including the living false gharial) within Gavialidae have indicated that the members of Gryposuchinae and the genus Gryposuchus may in fact be paraphyletic and rather an evolutionary grade towards Gavialis and the gharial, as shown in the cladogram below:

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Gryposuchinae

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

In research: Gryposuchinae 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 Gryposuchinae 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: Gryposuchinae is common in secondary-school and first-year university syllabi. It links to neighbouring topics Chattian first appearances, Gavialidae, Neogene crocodylomorphs, so understanding it makes those chapters shorter.
In everyday life: Look for Gryposuchinae 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 Gryposuchinae in 20 minutes

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

Frequently asked questions

What is Gryposuchinae in simple terms?

Gryposuchinae is an extinct subfamily of gavialid crocodylians. Gryposuchines lived mainly in the Miocene of South America.

Why does Gryposuchinae 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 Gryposuchinae?

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 Gryposuchinae.