biology

Uragasaurus

Uragasaurus 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 Uragasaurus rather than just read about it. In short: Uragasaurus (lit. 'serpent lizard') is an extinct genus of mamenchisaurid sauropod dinosaur known from the Late Jurassic Phu Kradung Formation of Thailand. The genus contains a single species, Uragasaurus kalasinensis, known from a single dorsal (trunk) vertebra.

Key takeaways

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

Reference excerpt

Uragasaurus (lit. 'serpent lizard') is an extinct genus of mamenchisaurid sauropod dinosaur known from the Late Jurassic Phu Kradung Formation of Thailand. The genus contains a single species, Uragasaurus kalasinensis, known from a single dorsal (trunk) vertebra. It is the first member of the family Mamenchisauridae named from Thailand.

Discovery and naming

The Uragasaurus fossil material was discovered in outcrops of the lower Phu Kradung Formation (Phu Noi locality), part of the Khorat Group, in Kalasin Province of northeastern Thailand. The specimen is housed in the Palaeontological Research and Education Centre (PRC) at Mahasarakham University, where it is permanently accessioned as specimen PRC 460. It consists of a single anterior (toward the front) dorsal vertebra. Taphonomic compression has flattened the bone anteroposteriorly (from front to back). In 2026, Apirut Nilpanapan and colleagues described Uragasaurus kalasinensis as a new genus and species of mamenchisaurid sauropod based on these fossil remains, establishing PRC 460 as the holotype specimen. The generic name, Uragasaurus, combines the Sanskrit word उरग, meaning 'serpent' or 'snake', with the Ancient Greek σαῦρος (saûros), meaning 'lizard'. The specific name, kalasinensis, references the discovery of the species in Kalasin Province. A middle cervical vertebra, right cervical rib, two anterior dorsal vertebral neural arches and a mid-posterior (toward the rear) dorsal vertebra, a left coracoid, and a left fibula were found disarticulated but in close association with the holotype of U. kalasinensis. They cannot be confidently referred to this species due to the absence of shared or diagnostic anatomical features. An isolated dorsal vertebra from the mid-late Jurassic Khlong Min Formation of Thailand was described by Buffetaut et al. in 2005, which represents the oldest mamenchisaurid occurrence in Southeast Asia. Suteethorn et al. (2013) then described a posterior cervical vertebra from the Phu Kradung Formation (Phu Dan Ma locality). These specimens remained unnamed, making Uragasaurus the first mamenchisaurid from the country to be given a scientific name.

Description

Nilpanapan et al. (2026) recognized a single autapomorphy (unique derived character) distinguishing Uragasaurus from all other mamenchisaurids: the distal (toward the tip) end of the transverse processes on the anterior dorsal vertebra have a prominent pneumatic fossa in an elongate teardrop shape. More complete relatives are characterized by their greatly elongated necks.

Classification To test the affinities and relationships of Uragasaurus, Nilpanapan et al. (2026) included it in an updated version of the phylogenetic matrix of Moore et al. (2023). Uragasaurus was recovered as an early-diverging member of the eusauropod clade Mamenchisauridae, diverging after Tienshanosaurus but before Qijianglong. These results are displayed in the cladogram below. The relationships among mamenchisaurids in their analysis were weakly supported, partly due to the fragmentary nature of some taxa, such as Uragasaurus. The clade including Tienshanosaurus and all more derived mamenchisaurids is supported by three anatomical characters, only one of which can be recognized in Uragasaurus: the presence of a bifurcated (split into two) neural spine on the anterior dorsal vertebra.

References

Illustrations

Worked examples

Example 1 — a first encounter with Uragasaurus

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

In research: Uragasaurus 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 Uragasaurus 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: Uragasaurus is common in secondary-school and first-year university syllabi. It links to neighbouring topics Dinosaur genera, Dinosaurs of Thailand, Fossil taxa described in 2026, so understanding it makes those chapters shorter.
In everyday life: Look for Uragasaurus 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 Uragasaurus in 20 minutes

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

Frequently asked questions

What is Uragasaurus in simple terms?

Why does Uragasaurus 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 Uragasaurus?

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 Uragasaurus.