science

Pachycorioolithus

Pachycorioolithus 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 Pachycorioolithus rather than just read about it. In short: Pachycorioolithus is an oogenus of small, thin-shelled fossil egg from the early Cretaceous in China. It probably belongs to a bird, though there is a possibility the parent was a non-avian theropod.

Key takeaways

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

Reference excerpt

Pachycorioolithus is an oogenus of small, thin-shelled fossil egg from the early Cretaceous in China. It probably belongs to a bird, though there is a possibility the parent was a non-avian theropod. It was named in 2016, based on a single specimen found in Zhejiang.

Description Pachycorioolithus is represented in the fossil record by a single, 80% complete fossil egg. It is elongated, measuring 50 mm (2.0 in) long by 32 mm (1.3 in) across, and smooth-surfaced. Thin pores (20 to 30 μm in diameter) cut through the eggshell. The eggshell is very thin, measuring only 166 μm thick, and is composed of three structural layers: the mammillary, continuous, and external layers. Pachycorioolithus is unique for having an external layer thicker than its continuous layer, with an external to continuous layer ratio of 1.6:1. This sets it apart from nearly all other known eggs. An unnamed Brazilian fossil egg also has an external layer thicker than continuous layer, but only barely thicker. Also, a few modern bird eggs have a similar, extremely thick external layer. These examples appear to result from convergent evolution, as they represent isolated cases in different clades. Based on its unique characteristics, Lawver et al. (2016) assigned Pachycorioolithus to its own monotypic oofamily, Pachycorioolithidae.

Parentage Though no embryo was found in the egg, Pachycorioolithus can be referred to Theropoda by the characteristics of its eggshell. However, it is uncertain whether the parent was a bird or not. Most non-avian dinosaurs have a two- or one-layered eggshell, whereas birds typically have a three-layered eggshell (like Pachycorioolithus). However, most Mesozoic bird eggs have only two layers and some non-avian dinosaur eggs have three layers, so this trait alone cannot be used to identify bird eggs. Lawver et al. (2016) believed it likely that P. jinyunensis pertains to a bird because of its small size and extremely thin shell, but they could not exclude the possibility that it was laid by a small, non-avian, theropod.

Distribution The only known P. jinyunensis specimen was discovered in a quarry near Shuhong, a town in Jinyun County in Zhejiang. This site is part of the Liangtoutang Formation, dating to the Albian.

Discovery and Naming Pachycorioolithus was first described in 2016 by a team of paleontologists consisting of Daniel R. Lawver and Frankie D. Jackson of the Montana State University, Jin Xingsheng of the Zhejiang Museum of Natural History, and Wang Qiongying of the Jinyun Museum. It was based on a single egg specimen housed in the Jinyun Museum. They gave it the name Pachycorioolithus jinyunensis, from the Greek "pachys" (thick) and "corys" (helmet), a reference to its thick outer layer, combined with "oolithus", the standard suffix for oogenus names, meaning "stone egg". The specific epithet means "from Jinyun", the county where it was found.

References

Worked examples

Example 1 — a first encounter with Pachycorioolithus

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

In research: Pachycorioolithus 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 Pachycorioolithus 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: Pachycorioolithus is common in secondary-school and first-year university syllabi. It links to neighbouring topics Dinosaur reproduction, Egg fossils, Fossil parataxa described in 2016, so understanding it makes those chapters shorter.
In everyday life: Look for Pachycorioolithus 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 Pachycorioolithus in 20 minutes

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

Frequently asked questions

What is Pachycorioolithus in simple terms?

Pachycorioolithus is an oogenus of small, thin-shelled fossil egg from the early Cretaceous in China. It probably belongs to a bird, though there is a possibility the parent was a non-avian theropod.

Why does Pachycorioolithus 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 Pachycorioolithus?

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 Pachycorioolithus.