science

Proceratosauridae

Proceratosauridae is a science 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 Proceratosauridae rather than just read about it. In short: Proceratosauridae is a family or clade of tyrannosauroid theropod dinosaurs from the Middle Jurassic to the Early Cretaceous. Distinguishing features Unlike the advanced tyrannosaurids but similar to primitive tyrannosauroids like Dilong, proceratosaurids were generally small (with the exception of the possible proceratosaurids Yutyrannus and Sinotyrannus) and had fairly long, three-fingered arms capable of grasping…

Key takeaways

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

Reference excerpt

Proceratosauridae is a family or clade of tyrannosauroid theropod dinosaurs from the Middle Jurassic to the Early Cretaceous.

Distinguishing features Unlike the advanced tyrannosaurids but similar to primitive tyrannosauroids like Dilong, proceratosaurids were generally small (with the exception of the possible proceratosaurids Yutyrannus and Sinotyrannus) and had fairly long, three-fingered arms capable of grasping prey. In comparison to other members of Tyrannosauroidea, proceratosaurids can be distinguished by the following features according to phylogenetic analyses by Averianov et al. (2010) and Loewen et al. (2013) :

A sagittal cranial crest formed by the nasals starting at the junction of the premaxilla and nasals. Extremely elongated external nares, with posterior margins posterior to the anterior margin of the antorbital fossa and maxillary fenestrae. A short ventral margin of the premaxilla. The depth of the antorbital fossa ventral to the antorbital fenestra being much greater than that of the maxilla below the antorbital fossa. A ventrally concave ischium. A convex tubercule on the anterior margin of the pubis just ventral to contact with the ilium. A short and shallow concave step on the anterior margin of the maxilla.

Classification

The family belongs or is closely related to the tyrannosaur lineage. It was first named in 2010 by Oliver Rauhut and colleagues in their re-evaluation of the type genus, Proceratosaurus. Their study supported the idea that Proceratosaurus is a coelurosaur, a tyrannosauroid, and most closely related to the Chinese tyrannosauroid Guanlong. They defined the clade containing these two dinosaurs as all theropods closer to Proceratosaurus than to Tyrannosaurus, Allosaurus, Compsognathus, Coelurus, Ornithomimus, or Deinonychus. Later studies included the Russian Kileskus and the Chinese Sinotyrannus in the family. By the mid-2010s, Proceratosauridae was considered to include Proceratosaurus, Guanlong, Kileskus, Sinotyrannus, and the genera Stokesosaurus, Juratyrant, and Dilong previously recognized as non-proceratosaurid tyrannosauroids. In their re-evaluation of Proceratosaurus, Rauhut et al. stated that tooth taxa from the Late Jurassic and Early Cretaceous previously assigned to the dromaeosaurid subfamily Velociraptorinae may instead be proceratosaurid in nature, due to the similarity between the teeth of the two groups and the fact that velociraptorines are otherwise unknown from the fossil record until the Late Cretaceous. This would mean that Nuthetes and other dubious genera are potential proceratosaurids. Below is the cladogram by Loewen et al. in 2013.

An analysis by Brusatte et al. in 2016 provides both parsimony and Bayesian phylogenetic analyses, with Yutyrannus being placed within Proceratosauridae as a sister taxon to Sinotyrannus and Juratyrant and Stokesosaurus being placed as more advanced tyrannosauroids in each instance. The Bayesian analysis is shown below.

Below is a cladogram from Naish and Cau (2022):

In their comprehensive revision of the enigmatic Brazilian coelurosaurians Mirischia and Santanaraptor, Delcourt et al. (2025) consistently supported a clade containing Dilong, Guanlong, Kileskus and Proceratosaurus. Tanycolagreus was grouped with this clade in equal-weight phylogenetic analyses, but was also grouped with Mirischia, Santanaraptor and Juratyrant in implied-weight phylogenetic analyses. Unlike previous analyses, they found the Proceratosauridae as early-diverging maniraptoromorphs outside Tyrannosauroidea.

Illustrations

Worked examples

Example 1 — a first encounter with Proceratosauridae

Start with the simplest possible case. Write down what Proceratosauridae claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 Proceratosauridae 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 Proceratosauridae 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 Proceratosauridae

In research: Proceratosauridae appears in science 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 Proceratosauridae 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: Proceratosauridae is common in secondary-school and first-year university syllabi. It links to neighbouring topics Dinosaur families, Proceratosauridae, so understanding it makes those chapters shorter.
In everyday life: Look for Proceratosauridae 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 Proceratosauridae in 20 minutes

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

Frequently asked questions

What is Proceratosauridae in simple terms?

Proceratosauridae is a family or clade of tyrannosauroid theropod dinosaurs from the Middle Jurassic to the Early Cretaceous. Distinguishing features Unlike the advanced tyrannosaurids but similar to primitive tyrannosauroids like Dilong, proceratosaurids were generally small (with the exception of…

Why does Proceratosauridae matter?

Because it connects several science 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 Proceratosauridae?

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 Proceratosauridae.