biology

Indosaurus

Indosaurus 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 Indosaurus rather than just read about it. In short: Indosaurus (lit. 'Indian lizard') is a genus of carnivorous theropod dinosaur that lived in what is now India, about 69 to 66 million years ago during the Maastrichtian division of the Late Cretaceous. Discovery and naming The now-lost holotype was discovered between 1917 and 1919 in Jabalpur, India (GSI K27/565), by Charles Alfred Matley.The type species, Indosaurus matleyi, was named by Huene and Matley in 1933 ma…

Key takeaways

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

Reference excerpt

Discovery and naming

The now-lost holotype was discovered between 1917 and 1919 in Jabalpur, India (GSI K27/565), by Charles Alfred Matley.The type species, Indosaurus matleyi, was named by Huene and Matley in 1933 making Indosaurus the first majungasaurine to be discovered. The generic name refers to India and the specific name honours Matley. This species now also includes Megalosaurus matleyi. Some paleontologists have speculated that Indosuchus, Lametasaurus and Indosaurus should be considered as nomina dubia.

Description The parietal of the frontal-parietal region is broad whereas the lower surface of the frontal is wide, the transverse crest lies above and behind the orbit. The frontals are concave and decline in to the front of the cranium. The supratemporal fossa is short and broad as in Antrodemus. The incomplete skull is of unusual thickness, although it lacked a dome on frontal bones as seen in Majungasaurus. It would have also lacked the paired frontal horns seen in Carnotaurus. Both Indosuchus and Indosaurus had a conservative skull roof which was dorsoventrally thickened but did not process prominences above the skull roof, similar to the condition seen in Abelisaurus. The species I. matleyi weighed roughly 700 kg (1,500 lb).

Classification Originally assigned by Huene to the Allosauridae, Indosaurus is today considered a member of the Abelisauridae family. It shows similarities to the other Abelisaurids from India, such as Rajasaurus and Rahiolisaurus, and is hence usually placed within Abelisauridae, though the fragmentary nature for this taxon makes it difficult to recognize its exact taxonomic validity. In 2014 Thierry Tortosa erected the subfamily Majungasaurinae. This was to separate Arcovenator, Majungasaurus, Indosaurus, Rahiolisaurus, and Rajasaurus from South American abelisaurids based on physical characteristics such as elongated antorbital fenestrae in front of the eye sockets, and a sagittal crest that widens into a triangular surface towards the front of the head. It was suggested that the abelisaurids migrated between Africa, Europe, India and Madagascar, which would isolate the South American abelisaurids. It is possible that migration occurred between Europe and India across Africa given its proximity to both, and the volcanic Dras-Kohistan island arc may have allowed island hopping and an indirect path to Asia, though these are still questionable explanations. The following cladogram was recovered by Tortosa (2014):

Paleoecology Indosaurus lived in the Lameta Formation during the Maastrichtian age of the Cretaceous period. It is known to have lived alongside sauropods like Isisaurus, Jainosaurus and the dubious Titanosaurus, which it may have preyed upon. Other ceratosaurs such as the abelisaurid Rajasaurus, Rahiolisaurus and Indosuchus are known from the formation, along with the noasaurid Laevisuchus. The ichnogenus Deltapodus is also known from the formation, which may belong to the youngest know stegosaurid. The madtsoiid snake Sanajeh was also contemporaneous to Indosaurus. The rocks of the Lameta formation appear to have been deposited in fluvial or lacustrine conditions. The environment at the time of deposition has alternatively been considered semi-arid, or tropical humid. The dinosaurs in India probably all went extinct due to volcanic activity around 350,000 years before the Cretaceous–Paleogene boundary. Dinosaurs probably avoided areas with volcanic fissure vents and lava flows.

Illustrations

Worked examples

Example 1 — a first encounter with Indosaurus

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

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

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

Frequently asked questions

What is Indosaurus in simple terms?

Indosaurus (lit. 'Indian lizard') is a genus of carnivorous theropod dinosaur that lived in what is now India, about 69 to 66 million years ago during the Maastrichtian division of the Late Cretaceous. Discovery and naming The now-lost holotype was discovered between 1917 and 1919 in Jabalpur, Indi…

Why does Indosaurus 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 Indosaurus?

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 Indosaurus.