biology

Toxochelys

Toxochelys 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 Toxochelys rather than just read about it. In short: Toxochelys () is an extinct genus of marine turtle from the Late Cretaceous period. It is the most commonly found fossilized turtle species in the Smoky Hill Chalk, in western Kansas.

Key takeaways

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

Reference excerpt

Toxochelys () is an extinct genus of marine turtle from the Late Cretaceous period. It is the most commonly found fossilized turtle species in the Smoky Hill Chalk, in western Kansas.

Description Toxochelys had carapace about 90 centimetres (3.0 ft) in length. Two species in the genus are recognized, Toxochelys latiremis and Toxochelys moorevillensis. Phylogenetic analysis shows that Toxochelys belong to an extinct lineage of turtles transitional between modern sea turtles and other turtles. Toxochelys bauri Williston, 1905, based on the skeleton YPM 1786, is a synonym of Ctenochelys stenoporus. Toxochelys are currently thought to be the oldest member and the last common ancestor of all extinct marine turtles. Even though Toxochelys shared similar limb characteristics with other species as Cheloniidae and Protostegidae, they evolved independently to pass down new limb features to future generations. These features allowed for advanced mobility of the hand.

Phylogeny Toxochelys latiremis in a cladogram from the analysis of Gentry et al., 2019:

References

Further reading Cope, E. D. 1873. [On Toxochelys latiremis]. Proceedings of the Academy of Natural Sciences of Philadelphia 25:10. Hay, O. P. 1896. On the skeleton of Toxochelys latiremis. Publ. Field Columbian Museum, Zoological Ser. (later Fieldiana: Zoology), 1(5):101–106, pls. 14 &15. Case, E.C. 1898. Toxochelys. The University Geological Survey of Kansas, Part IV. 4:370–385. pls. 79–84. Hay, O.P. 1905. A revision of the species of the family of fossil turtles called Toxochelyidae, with descriptions of two new species of Toxochelys and a new species of Porthochelys. Bulletin of the American Museum of Natural History 21(10):177–185. Druckenmiller, P. S., A. J. Daun, J. L. Skulan and J. C. Pladziewicz. 1993. Stomach contents in the upper Cretaceous shark Squalicorax falcatus. Journal of Vertebrate Paleontology. 13(supplement. to no. 3):33A. Carrino, M.H. 2007. Taxonomic comparison and stratigraphic distribution of Toxochelys (Testudines: Cheloniidae) of South Dakota. pp. 111–132 in Martin, J.E. and Parris D.C. (eds.), The Geology and Paleontology of the Late Cretaceous Marine Deposits of the Dakotas. Geological Society of America, Special Paper 427. Konuki, R. 2008. Biostratigraphy of sea turtles and possible bite marks on a Toxochelys (Testudine, Chelonioidea) from the Niobrara Formation (Late Santonian), Logan County, Kansas and paleoecological implications for predator–prey relationships among large marine vertebrates. Unpublished Masters thesis, Fort Hays State University, Hays, Kansas, 141 pp, Appen. I-VI. Matzke, A.T. 2008. A juvenile Toxochelys latiremis (Testudines, Cheloniidae) from the Upper Cretaceous Niobrara Formation of Kansas, USA. Neues Jahrbuch für Geologie und Paläontologie. Abhandlungen 249(3):371–380. Matzke, A.T. 2009. Osteology of the skull of Toxochelys (Testudines, Chelonioidea) (with 25 text-figures). Palaeontographica Abteilung A 288(4):93–150.

External links www.scistp.org gsa.confex.com njfossils.net

Illustrations

Worked examples

Example 1 — a first encounter with Toxochelys

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

In research: Toxochelys 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 Toxochelys 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: Toxochelys is common in secondary-school and first-year university syllabi. It links to neighbouring topics Chelonioidea, Extinct turtles, Fossil taxa described in 1873, so understanding it makes those chapters shorter.
In everyday life: Look for Toxochelys 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 Toxochelys in 20 minutes

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

Frequently asked questions

What is Toxochelys in simple terms?

Toxochelys () is an extinct genus of marine turtle from the Late Cretaceous period. It is the most commonly found fossilized turtle species in the Smoky Hill Chalk, in western Kansas.

Why does Toxochelys 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 Toxochelys?

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 Toxochelys.