biology

Sonorasaurus

Sonorasaurus 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 Sonorasaurus rather than just read about it. In short: Sonorasaurus is a genus of brachiosaurid sauropod dinosaur from the Early to Late Cretaceous (Albian to Cenomanian stages, around 112 to 93 million years ago). Its fossils have been found in southern Arizona, United States.

Key takeaways

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

Reference excerpt

Sonorasaurus is a genus of brachiosaurid sauropod dinosaur from the Early to Late Cretaceous (Albian to Cenomanian stages, around 112 to 93 million years ago). Its fossils have been found in southern Arizona, United States. Its name, which means "Sonora lizard", comes from the Sonora River that flows in the Sonoran Desert where its fossils were first found. The type species is S. thompsoni, described by Ratkevich in 1998.

Discovery Fossilized remains were discovered in November 1994 by geology student Richard Thompson in the Turney Ranch Formation in the Whetstone Mountains, located in the Chihuahua Desert region of the Sonoran Desert in southern Arizona. Thompson had investigated a previously almost unexplored region, where fossils proved to be plentiful and directly accessible on the surface. A relatively complete sauropod skeleton was weathering out on a rock wall. He informed paleontologist Ronald Paul Ratkevich of the Arizona-Sonora Desert Museum, Tucson of the find. Ratkevich assembled a team of volunteers and began securing the bones in the spring of 1995; excavations would only end in 1999. He assumed the fossils represented a sauropod but was no expert on that taxon. The curator of geology of the museum, David W. Thayer, thought it might be a therizinosaur, mistaking a tail chevron bone for the long hand claw typical of that group. In 1995, Ratkevich and Tayer first reported the find, already using the name "Sonorasaurus" but informally, so that it remained a nomen nudum. Both men now asked dinosaur expert Edwin Harris Colbert to identify the animal. Colbert, having seen only pictures, suggested it might be a member of the Hadrosauridae. Ratkevich and Thayer then visited the displays in the American Museum of Natural History, concluding their find was rather dissimilar to the hadrosaurid skeletons shown there, so that it must represent a species new to science. Ratkevich considered naming it "Chihuahuasaurus" but ultimately shied away from the comical contrast between the gigantic sauropod and the minute dog breed. In 1996, a subsequent article tried to fit the bones found, in a diagram of the hadrosaurid Kritosaurus. This attempt largely failed, with an ilium being mistaken for a shoulder blade. Again, the name "Sonorasaurus" was used but still invalidly. Sonorasaurus was finally formally described in 1998 by Ratkevich, who identified it as a brachiosaurid sauropod. Dating of the specimen found it to be the earliest known brachiosaurid to have lived in the 'middle' Cretaceous Period of North America. On April 10, 2018, Sonorasaurus was declared the state dinosaur of Arizona.

Description The holotype of Sonorasaurus, ASDM 500, is an incomplete skeleton consisting of various postcranial elements, many of which are fragmentary. A complete dorsal rib from the same horizon, ASDM 807, may also be referrable to S. thompsoni. Sonorasaurus is estimated to have been about 15 meters (49 feet) long, 8 meters (26 feet) tall, and weighed 10 metric tons (11 short tons), which is about one third of the size of Brachiosaurus.

Classification Ratkevich initially identified Sonorasaurus as a brachiosaurid. However phylogenetic studies in the following years failed to find a consensus, with some finding it to lie within Brachiosauridae and others outside of it. In no analysis was the recovered phylogenetic position of Sonorasaurus strongly supported until D'Emic et al. (2016), which found Sonorasaurus to fall confidently within the Brachiosauridae. However the authors noted that additional data was still required to firmly establish its lower-level affinities. Sonorasaurus in a cladogram of Brachiosauridae after Mannion et al. (2017).

In Mannion et al. (2019) it is still described as a brachiosaurid.

References

External links "Sonorasaurus RATKEVICH, 1998". paleofile.com. Archived from the original on June 8, 2023. "Sauropoda: Macronaria". palaeos.com. Archived from the original on April 21, 2023. "Sonorasaurus". Discover.{{cite web}}: CS1 maint: deprecated archival service (link) "Analysis of the Sonorasaurus site (technical)". arizona.edu. Archived from the original on October 27, 2021.

Illustrations

Worked examples

Example 1 — a first encounter with Sonorasaurus

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

In research: Sonorasaurus 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 Sonorasaurus 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: Sonorasaurus is common in secondary-school and first-year university syllabi. It links to neighbouring topics Albian dinosaurs, Brachiosauridae, Cenomanian dinosaurs, so understanding it makes those chapters shorter.
In everyday life: Look for Sonorasaurus 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 Sonorasaurus in 20 minutes

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

Frequently asked questions

What is Sonorasaurus in simple terms?

Why does Sonorasaurus 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 Sonorasaurus?

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 Sonorasaurus.