biology

Genusaurus

Genusaurus 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 Genusaurus rather than just read about it. In short: Genusaurus ( JEN-yuu-SOR-əs; meaning "knee lizard") is a genus of abelisaurid theropod from the Early Cretaceous. Its fossils were found in France.

Key takeaways

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

Reference excerpt

Genusaurus ( JEN-yuu-SOR-əs; meaning "knee lizard") is a genus of abelisaurid theropod from the Early Cretaceous. Its fossils were found in France. Genusaurus is believed to have lived during the Albian stage, around 112-100 million years ago.

Description Genusaurus possesses several distinguishing traits. The dorsal vertebrae are elongated. The elements of the pelvis are strongly fused. The thighbone shows a low bone plateau below the major trochanter; to the front an accessory trochanter is present. The epicondyle of the inner femoral condyle is well-developed. The cnemial crest strongly extends to the front and is curved upwards. The fibula has a distinctive boss serving as an attachment for the Musculus iliofibularis. The upper inner side of the fibula is strongly hollowed out.

Size Genusaurus was originally estimated to have been 3.16 metres (10.4 ft) long. From the 38 centimetres (15 in) thighbone, a weight of 129.6 kilograms (286 lb) was extrapolated. Later estimates, while confirming the length of 3 metres (9.8 ft), have reduced the weight to 50 kilograms (110 lb), or even 35 kilograms (77 lb). In 2016, its length was estimated at 3.6 metres (12 ft), making it among the smallest known abelisaurids.

Discovery and naming The type species, Genusaurus sisteronis, is the only named species. It is based on a partial skeleton found in 1984-1986 in the Albian Bevons Beds, holotype MNHN Bev.1. The holotype contains seven partial dorsal vertebrae, a piece of a sacral, a piece of an ilium, the top of a pubic bone, a thighbone, the top of a shinbone, the top of a fibula and a metatarsal. It was named and described by Hugues Accarie, Bernard Beaudoin, Jean Dejax, Gérard Friès, Jean-Guy Michard and Philippe Taquet in 1995. The genus name is derived from the Latin word genu (knee) and refers to the cnemial crest in front of the proximal end of the tibia. The specific name refers to Sisteron, the town near which the specimen was found.

Classification Accarie et al. assigned Genusaurus to the ceratosaur group of theropods, more precisely to the Coelophysoidea. A 2008 cladistic analysis by Carrano and Sampson placed Genusaurus in the Noasauridae along with Laevisuchus, Masiakasaurus, Noasaurus, and Velocisaurus; in turn, noasaurids are part of the Abelisauroidea group, which is part of the ceratosaur group. Subsequent phylogenetic analyses found Genusaurus to be either a member of the Noasauridae or Abelisauridae. In 2025, Eric Buffetaut reexamined the holotype and suggested that it should be placed into Furileusauria.

Worked examples

Example 1 — a first encounter with Genusaurus

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

In research: Genusaurus 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 Genusaurus 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: Genusaurus is common in secondary-school and first-year university syllabi. It links to neighbouring topics Abelisauridae, Albian dinosaurs, Dinosaur genera, so understanding it makes those chapters shorter.
In everyday life: Look for Genusaurus 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 Genusaurus in 20 minutes

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

Frequently asked questions

What is Genusaurus in simple terms?

Genusaurus ( JEN-yuu-SOR-əs; meaning "knee lizard") is a genus of abelisaurid theropod from the Early Cretaceous. Its fossils were found in France.

Why does Genusaurus 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 Genusaurus?

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 Genusaurus.