biology

Sandstone night lizard

Sandstone night lizard 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 Sandstone night lizard rather than just read about it. In short: The sandstone night lizard (Xantusia gracilis) is a species of lizard in the family Xantusiidae. It is endemic to Truckhaven Rocks, a 3 km2 (1.2 sq mi) area in the southeastern part of the Santa Rosa Mountains of California, United States.

Key takeaways

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

Reference excerpt

The sandstone night lizard (Xantusia gracilis) is a species of lizard in the family Xantusiidae. It is endemic to Truckhaven Rocks, a 3 km2 (1.2 sq mi) area in the southeastern part of the Santa Rosa Mountains of California, United States.

Taxonomy The first description of Xantusia gracilis was published by Lee Grismer and Mark Galvan in 1986, who used the name Xantusia henshawi gracilis. The name gracilis is taken from the Latin for 'slender', chosen in reference to the lizard's form. The holotype, a male, was collected by Grismer and Galvan in February 1985, with the type locality being Truckhaven Rocks, Anza-Borrego Desert State Park, California. Robert Lovich was first to recognized gracilis as being a separate species from Xantusia henshawi, doing so in 2001 after conducting a molecular study.

Description The sandstone night lizard usually has a snout–vent length of 60–71 mm (2.4–2.8 in) in adulthood. Its back is white to yellow with small, uniform black dots, and its underside is white with minor black dotting in some areas. The colouration is in contrast to its relatives Xantusia henshawi and Xantusia bolsonae, who have much more extensive markings on their backs and significant black dotting on their undersides. Other morphological differences to its relatives include a greatly enlarged temporal scale and a narrower head. It also spends more time on the ground instead of climbing than its relatives do.

Distribution and habitat The sandstone night lizard is only known to inhabit a region in the southeastern part of the Santa Rosa Mountains known as Truckhaven Rocks, located 24.5 km (15.2 mi) to the east and 6.3 km (3.9 mi) to the north of Borrego Springs, San Diego County. The region consists mainly of sandstone and siltstone, sits at an elevation of about 240–305 m (787–1,001 ft), and is roughly 3 km (1.9 mi) long east to west and 1.3 km (0.81 mi) long north to south, covering an area of about 3 km2 (1.2 sq mi). Sandstone crevices and burrows make up the sandstone night lizard's habitat, with most of these being found in and along the many canyons of Truckhaven Rocks, most of which are 30–60 m (98–197 ft) deep. The species was listed as vulnerable on the IUCN Red List after a 2007 assessment due to the very limited extent of its habitat.

References

Illustrations

Worked examples

Example 1 — a first encounter with Sandstone night lizard

Start with the simplest possible case. Write down what Sandstone night lizard 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 Sandstone night lizard 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 Sandstone night lizard 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 Sandstone night lizard

In research: Sandstone night lizard 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 Sandstone night lizard 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: Sandstone night lizard is common in secondary-school and first-year university syllabi. It links to neighbouring topics Endemic fauna of California, Fauna of the Colorado Desert, IUCN Red List vulnerable species, so understanding it makes those chapters shorter.
In everyday life: Look for Sandstone night lizard 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Sandstone night lizard” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Sandstone night lizard in 20 minutes

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

Frequently asked questions

What is Sandstone night lizard in simple terms?

Why does Sandstone night lizard 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 Sandstone night lizard?

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 Sandstone night lizard.